Merge: nitrpg: Move `nitrpg` to its own repository
[nit.git] / lib / github / api.nit
index 18880ec..fb6fff9 100644 (file)
 module api
 
 import github_curl
+intrude import json::serialization_read
 
 # Client to Github API
 #
 # To access the API you need an instance of a `GithubAPI` client.
 #
-# ~~~
+# ~~~nitish
 # # Get Github authentification token.
 # var token = get_github_oauth
 # assert not token.is_empty
@@ -36,7 +37,7 @@ import github_curl
 #
 # The API client allows you to get Github API entities.
 #
-# ~~~
+# ~~~nitish
 # var repo = api.load_repo("nitlang/nit")
 # assert repo != null
 # assert repo.name == "nit"
@@ -88,28 +89,40 @@ class GithubAPI
                ghcurl = new GithubCurl(auth, user_agent)
        end
 
+       # Deserialize an object
+       fun deserialize(string: String): nullable Object do
+               var deserializer = new GithubDeserializer(string)
+               var res = deserializer.deserialize
+               # print deserializer.errors.join("\n") # DEBUG
+               return res
+       end
+
        # Execute a GET request on Github API.
        #
        # This method returns raw json data.
        # See other `load_*` methods to use more expressive types.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var obj = api.get("repos/nitlang/nit")
-       #     assert obj isa JsonObject
-       #     assert obj["name"] == "nit"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var obj = api.get("/repos/nitlang/nit")
+       # assert obj isa JsonObject
+       # assert obj["name"] == "nit"
+       # ~~~
        #
        # Returns `null` in case of `error`.
        #
-       #     obj = api.get("foo/bar/baz")
-       #     assert obj == null
-       #     assert api.was_error
-       #     var err = api.last_error
-       #     assert err isa GithubError
-       #     assert err.name == "GithubAPIError"
-       #     assert err.message == "Not Found"
-       fun get(path: String): nullable Jsonable do
+       # ~~~nitish
+       # obj = api.get("/foo/bar/baz")
+       # assert obj == null
+       # assert api.was_error
+       # var err = api.last_error
+       # assert err isa GithubError
+       # assert err.name == "GithubAPIError"
+       # assert err.message == "Not Found"
+       # ~~~
+       fun get(path: String): nullable Serializable do
                path = sanitize_uri(path)
-               var res = ghcurl.get_and_parse("{api_url}/{path}")
+               var res = ghcurl.get_and_parse("{api_url}{path}")
                if res isa Error then
                        last_error = res
                        was_error = true
@@ -138,188 +151,389 @@ class GithubAPI
 
        # Load the json object from Github.
        # See `GithubEntity::load_from_github`.
-       protected fun load_from_github(key: String): JsonObject do
+       protected fun load_from_github(key: String): nullable GithubEntity do
                message(1, "Get {key} (github)")
                var res = get(key)
-               if was_error then return new JsonObject
-               return res.as(JsonObject)
+               if was_error then return null
+               return deserialize(res.as(JsonObject).to_json).as(nullable GithubEntity)
+       end
+
+       # Get the Github logged user from `auth` token.
+       #
+       # Loads the `User` from the API or returns `null` if the user cannot be found.
+       #
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var user = api.load_auth_user
+       # assert user.login == "Morriar"
+       # ~~~
+       fun load_auth_user: nullable User do
+               var user = load_from_github("/user")
+               if was_error then return null
+               return user.as(nullable User)
        end
 
        # Get the Github user with `login`
        #
        # Loads the `User` from the API or returns `null` if the user cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var user = api.load_user("Morriar")
-       #     assert user.login == "Morriar"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var user = api.load_user("Morriar")
+       # print user or else "null"
+       # assert user.login == "Morriar"
+       # ~~~
        fun load_user(login: String): nullable User do
-               var user = new User(self, login)
-               return user.load_from_github
+               return load_from_github("/users/{login}").as(nullable User)
        end
 
        # Get the Github repo with `full_name`.
        #
        # Loads the `Repo` from the API or returns `null` if the repo cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo.name == "nit"
-       #     assert repo.owner.login == "nitlang"
-       #     assert repo.default_branch.name == "master"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo.name == "nit"
+       # assert repo.owner.login == "nitlang"
+       # assert repo.default_branch == "master"
+       # ~~~
        fun load_repo(full_name: String): nullable Repo do
-               var repo = new Repo(self, full_name)
-               return repo.load_from_github
+               return load_from_github("/repos/{full_name}").as(nullable Repo)
+       end
+
+       # List of branches associated with their names.
+       fun load_repo_branches(repo: Repo): Array[Branch] do
+               message(1, "Get branches for {repo.full_name}")
+               var array = get("/repos/{repo.full_name}/branches")
+               var res = new Array[Branch]
+               if not array isa JsonArray then return res
+               var deser = deserialize(array.to_json)
+               if not deser isa Array[Object] then return res # empty array
+               for branch in deser do
+                       if not branch isa Branch then continue
+                       res.add branch
+               end
+               return res
+       end
+
+       # List of issues associated with their ids.
+       fun load_repo_issues(repo: Repo): Array[Issue] do
+               message(1, "Get issues for {repo.full_name}")
+               var res = new Array[Issue]
+               var issue = load_repo_last_issue(repo)
+               if issue == null then return res
+               res.add issue
+               while issue != null and issue.number > 1 do
+                       issue = load_issue(repo, issue.number - 1)
+                       if issue == null then continue
+                       res.add issue
+               end
+               return res
+       end
+
+       # Search issues in this repo form an advanced query.
+       #
+       # Example:
+       #
+       # ~~~nitish
+       # var issues = repo.search_issues("is:open label:need_review")
+       # ~~~
+       #
+       # See <https://developer.github.com/v3/search/#search-issues>.
+       fun search_repo_issues(repo: Repo, query: String): Array[Issue] do
+               query = "/search/issues?q={query} repo:{repo.full_name}"
+               var res = new Array[Issue]
+               var response = get(query)
+               if was_error then return res
+               var arr = response.as(JsonObject)["items"].as(JsonArray)
+               return deserialize(arr.to_json).as(Array[Issue])
+       end
+
+       # Get the last published issue.
+       fun load_repo_last_issue(repo: Repo): nullable Issue do
+               var array = get("/repos/{repo.full_name}/issues")
+               if not array isa JsonArray then return null
+               if array.is_empty then return null
+               var obj = array.first
+               if not obj isa JsonObject then return null
+               return deserialize(obj.to_json).as(nullable Issue)
+       end
+
+       # List of labels associated with their names.
+       fun load_repo_labels(repo: Repo): Array[Label] do
+               message(1, "Get labels for {repo.full_name}")
+               var array = get("repos/{repo.full_name}/labels")
+               if not array isa JsonArray then return new Array[Label]
+               return deserialize(array.to_json).as(Array[Label])
+       end
+
+       # List of milestones associated with their ids.
+       fun load_repo_milestones(repo: Repo): Array[Milestone] do
+               message(1, "Get milestones for {repo.full_name}")
+               var array = get("/repos/{repo.full_name}/milestones")
+               if not array isa JsonArray then return new Array[Milestone]
+               return deserialize(array.to_json).as(Array[Milestone])
+       end
+
+       # List of pull-requests associated with their ids.
+       #
+       # Implementation notes: because PR numbers are not consecutive,
+       # PR are loaded from pages.
+       # See: https://developer.github.com/v3/pulls/#list-pull-requests
+       fun load_repo_pulls(repo: Repo): Array[PullRequest] do
+               message(1, "Get pulls for {repo.full_name}")
+               var key = "/repos/{repo.full_name}"
+               var res = new Array[PullRequest]
+               var page = 1
+               loop
+                       var array = get("{key}/pulls?page={page}").as(JsonArray)
+                       if array.is_empty then break
+                       for obj in array do
+                               if not obj isa JsonObject then continue
+                               var pr = deserialize(array.to_json).as(nullable PullRequest)
+                               if pr == null then continue
+                               res.add pr
+                       end
+                       page += 1
+               end
+               return res
+       end
+
+       # List of contributor related statistics.
+       fun load_repo_contrib_stats(repo: Repo): Array[ContributorStats] do
+               message(1, "Get contributor stats for {repo.full_name}")
+               var res = new Array[ContributorStats]
+               var array = get("/repos/{repo.full_name}/stats/contributors")
+               if not array isa JsonArray then return res
+               return deserialize(array.to_json).as(Array[ContributorStats])
        end
 
        # Get the Github branch with `name`.
        #
        # Returns `null` if the branch cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var branch = api.load_branch(repo, "master")
-       #     assert branch.name == "master"
-       #     assert branch.commit isa Commit
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var branch = api.load_branch(repo, "master")
+       # assert branch.name == "master"
+       # assert branch.commit isa Commit
+       # ~~~
        fun load_branch(repo: Repo, name: String): nullable Branch do
-               var branch = new Branch(self, repo, name)
-               return branch.load_from_github
+               return load_from_github("/repos/{repo.full_name}/branches/{name}").as(nullable Branch)
+       end
+
+       # List all commits in `self`.
+       #
+       # This can be long depending on the branch size.
+       # Commit are returned in an unspecified order.
+       fun load_branch_commits(branch: Branch): Array[Commit] do
+               var res = new Array[Commit]
+               var done = new HashSet[String]
+               var todos = new Array[Commit]
+               todos.add branch.commit
+               loop
+                       if todos.is_empty then break
+                       var commit = todos.pop
+                       if done.has(commit.sha) then continue
+                       done.add commit.sha
+                       res.add commit
+                       var parents = commit.parents
+                       if parents == null then continue
+                       for parent in parents do
+                               todos.add parent
+                       end
+               end
+               return res
        end
 
        # Get the Github commit with `sha`.
        #
        # Returns `null` if the commit cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var commit = api.load_commit(repo, "64ce1f")
-       #     assert commit isa Commit
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var commit = api.load_commit(repo, "64ce1f")
+       # assert commit isa Commit
+       # ~~~
        fun load_commit(repo: Repo, sha: String): nullable Commit do
-               var commit = new Commit(self, repo, sha)
-               return commit.load_from_github
+               return load_from_github("/repos/{repo.full_name}/commits/{sha}").as(nullable Commit)
        end
 
        # Get the Github issue #`number`.
        #
        # Returns `null` if the issue cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var issue = api.load_issue(repo, 1)
-       #     assert issue.title == "Doc"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var issue = api.load_issue(repo, 1)
+       # assert issue.title == "Doc"
+       # ~~~
        fun load_issue(repo: Repo, number: Int): nullable Issue do
-               var issue = new Issue(self, repo, number)
-               return issue.load_from_github
+               return load_from_github("/repos/{repo.full_name}/issues/{number}").as(nullable Issue)
+       end
+
+       # List of event on this issue.
+       fun load_issue_comments(repo: Repo, issue: Issue): Array[IssueComment] do
+               var res = new Array[IssueComment]
+               var count = issue.comments or else 0
+               var page = 1
+               loop
+                       var array = get("/repos/{repo.full_name}/issues/{issue.number}/comments?page={page}")
+                       if not array isa JsonArray then break
+                       if array.is_empty then break
+                       for obj in array do
+                               if not obj isa JsonObject then continue
+                               var id = obj["id"].as(Int)
+                               var comment = load_issue_comment(repo, id)
+                               if comment == null then continue
+                               res.add(comment)
+                       end
+                       if res.length >= count then break
+                       page += 1
+               end
+               return res
+       end
+
+       # List of events on this issue.
+       fun load_issue_events(repo: Repo, issue: Issue): Array[IssueEvent] do
+               var res = new Array[IssueEvent]
+               var key = "/repos/{repo.full_name}/issues/{issue.number}"
+               var page = 1
+               loop
+                       var array = get("{key}/events?page={page}")
+                       if not array isa JsonArray or array.is_empty then break
+                       for obj in array do
+                               if not obj isa JsonObject then continue
+                               var event = deserialize(obj.to_json).as(nullable IssueEvent)
+                               if event == null then continue
+                               res.add event
+                       end
+                       page += 1
+               end
+               return res
        end
 
        # Get the Github pull request #`number`.
        #
        # Returns `null` if the pull request cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var pull = api.load_pull(repo, 1)
-       #     assert pull.title == "Doc"
-       #     assert pull.user.login == "Morriar"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var pull = api.load_pull(repo, 1)
+       # assert pull.title == "Doc"
+       # assert pull.user.login == "Morriar"
+       # ~~~
        fun load_pull(repo: Repo, number: Int): nullable PullRequest do
-               var pull = new PullRequest(self, repo, number)
-               return pull.load_from_github
+               return load_from_github("/repos/{repo.full_name}/pulls/{number}").as(nullable PullRequest)
        end
 
        # Get the Github label with `name`.
        #
        # Returns `null` if the label cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var labl = api.load_label(repo, "ok_will_merge")
-       #     assert labl != null
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var labl = api.load_label(repo, "ok_will_merge")
+       # assert labl != null
+       # ~~~
        fun load_label(repo: Repo, name: String): nullable Label do
-               var labl = new Label(self, repo, name)
-               return labl.load_from_github
+               return load_from_github("/repos/{repo.full_name}/labels/{name}").as(nullable Label)
        end
 
        # Get the Github milestone with `id`.
        #
        # Returns `null` if the milestone cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var stone = api.load_milestone(repo, 4)
-       #     assert stone.title == "v1.0prealpha"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var stone = api.load_milestone(repo, 4)
+       # assert stone.title == "v1.0prealpha"
+       # ~~~
        fun load_milestone(repo: Repo, id: Int): nullable Milestone do
-               var milestone = new Milestone(self, repo, id)
-               return milestone.load_from_github
+               return load_from_github("/repos/{repo.full_name}/milestones/{id}").as(nullable Milestone)
        end
 
        # Get the Github issue event with `id`.
        #
        # Returns `null` if the event cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo isa Repo
-       #     var event = api.load_issue_event(repo, 199674194)
-       #     assert event.actor.login == "privat"
-       #     assert event.event == "labeled"
-       #     assert event.labl.name == "need_review"
-       #     assert event.issue.number == 945
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo isa Repo
+       # var event = api.load_issue_event(repo, 199674194)
+       # assert event isa IssueEvent
+       # assert event.actor.login == "privat"
+       # assert event.event == "labeled"
+       # assert event.labl isa Label
+       # assert event.labl.name == "need_review"
+       # ~~~
        fun load_issue_event(repo: Repo, id: Int): nullable IssueEvent do
-               var event = new IssueEvent(self, repo, id)
-               return event.load_from_github
+               return load_from_github("/repos/{repo.full_name}/issues/events/{id}").as(nullable IssueEvent)
        end
 
        # Get the Github commit comment with `id`.
        #
        # Returns `null` if the comment cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var comment = api.load_commit_comment(repo, 8982707)
-       #     assert comment.user.login == "Morriar"
-       #     assert comment.body == "For testing purposes..."
-       #     assert comment.commit.sha == "7eacb86d1e24b7e72bc9ac869bf7182c0300ceca"
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var comment = api.load_commit_comment(repo, 8982707)
+       # assert comment.user.login == "Morriar"
+       # assert comment.body == "For testing purposes...\n"
+       # assert comment.commit_id == "7eacb86d1e24b7e72bc9ac869bf7182c0300ceca"
+       # ~~~
        fun load_commit_comment(repo: Repo, id: Int): nullable CommitComment do
-               var comment = new CommitComment(self, repo, id)
-               return comment.load_from_github
+               return load_from_github("/repos/{repo.full_name}/comments/{id}").as(nullable CommitComment)
        end
 
        # Get the Github issue comment with `id`.
        #
        # Returns `null` if the comment cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var comment = api.load_issue_comment(repo, 6020149)
-       #     assert comment.user.login == "privat"
-       #     assert comment.created_at.to_s == "2012-05-30T20:16:54Z"
-       #     assert comment.issue.number == 10
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var comment = api.load_issue_comment(repo, 6020149)
+       # assert comment.user.login == "privat"
+       # assert comment.created_at.to_s == "2012-05-30T20:16:54Z"
+       # assert comment.issue_number == 10
+       # ~~~
        fun load_issue_comment(repo: Repo, id: Int): nullable IssueComment do
-               var comment = new IssueComment(self, repo, id)
-               return comment.load_from_github
+               return load_from_github("/repos/{repo.full_name}/issues/comments/{id}").as(nullable IssueComment)
        end
 
        # Get the Github diff comment with `id`.
        #
        # Returns `null` if the comment cannot be found.
        #
-       #     var api = new GithubAPI(get_github_oauth)
-       #     var repo = api.load_repo("nitlang/nit")
-       #     assert repo != null
-       #     var comment = api.load_review_comment(repo, 21010363)
-       #     assert comment.path == "src/modelize/modelize_property.nit"
-       #     assert comment.original_position == 26
-       #     assert comment.pull.number == 945
+       # ~~~nitish
+       # var api = new GithubAPI(get_github_oauth)
+       # var repo = api.load_repo("nitlang/nit")
+       # assert repo != null
+       # var comment = api.load_review_comment(repo, 21010363)
+       # assert comment.path == "src/modelize/modelize_property.nit"
+       # assert comment.original_position == 26
+       # assert comment.pull_number == 945
+       # ~~~
        fun load_review_comment(repo: Repo, id: Int): nullable ReviewComment do
-               var comment = new ReviewComment(self, repo, id)
-               return comment.load_from_github
+               return load_from_github("/repos/{repo.full_name}/pulls/comments/{id}").as(nullable ReviewComment)
        end
 end
 
@@ -327,34 +541,10 @@ end
 #
 # Mainly a Nit wrapper around a JSON objet.
 abstract class GithubEntity
-
-       # Github API instance.
-       var api: GithubAPI
-
-       # FIXME constructor should be private
-
-       # Key used to access this entity from Github api base.
-       fun key: String is abstract
-
-       # JSON representation of `self`.
-       #
-       # This is the same json structure than used by Github API.
-       var json: JsonObject is noinit, protected writable
-
-       # Load `json` from Github API.
-       private fun load_from_github: nullable SELF do
-               json = api.load_from_github(key)
-               if api.was_error then return null
-               return self
-       end
-
-       redef fun to_s do return json.to_json
+       serialize
 
        # Github page url.
-       fun html_url: String do return json["html_url"].as(String)
-
-       # Set page url.
-       fun html_url=(url: String) do json["html_url"] = url
+       var html_url: nullable String is writable
 end
 
 # A Github user
@@ -362,24 +552,23 @@ end
 # Provides access to [Github user data](https://developer.github.com/v3/users/).
 # Should be accessed from `GithubAPI::load_user`.
 class User
-       super GithubEntity
-
-       redef var key is lazy do return "users/{login}"
+       super GitUser
+       serialize
 
        # Github login.
-       var login: String
-
-       # Init `self` from a `json` object.
-       init from_json(api: GithubAPI, json: JsonObject) do
-               init(api, json["login"].as(String))
-               self.json = json
-       end
+       var login: String is writable
 
        # Avatar image url for this user.
-       fun avatar_url: String do return json["avatar_url"].as(String)
+       var avatar_url: nullable String is writable
 
-       # Set avatar url.
-       fun avatar_url=(url: String) do json["avatar_url"] = url
+       # User public name if any.
+       var name: nullable String is writable
+
+       # User public email if any.
+       var email: nullable String is writable
+
+       # User public blog if any.
+       var blog: nullable String is writable
 end
 
 # A Github repository.
@@ -388,179 +577,19 @@ end
 # Should be accessed from `GithubAPI::load_repo`.
 class Repo
        super GithubEntity
-
-       redef var key is lazy do return "repos/{full_name}"
+       serialize
 
        # Repo full name on Github.
-       var full_name: String
-
-       # Init `self` from a `json` object.
-       init from_json(api: GithubAPI, json: JsonObject) do
-               init(api, json["full_name"].as(String))
-               self.json = json
-       end
+       var full_name: String is writable
 
        # Repo short name on Github.
-       fun name: String do return json["name"].as(String)
-
-       # Set repo full name
-       fun name=(name: String) do json["name"] = name
+       var name: String is writable
 
        # Get the repo owner.
-       fun owner: User do return new User.from_json(api, json["owner"].as(JsonObject))
-
-       # Set repo owner
-       fun owner=(owner: User) do json["owner"] = owner.json
-
-       # List of branches associated with their names.
-       fun branches: Map[String, Branch] do
-               api.message(1, "Get branches for {full_name}")
-               var array = api.get("repos/{full_name}/branches")
-               var res = new HashMap[String, Branch]
-               if not array isa JsonArray then return res
-               for obj in array do
-                       if not obj isa JsonObject then continue
-                       var name = obj["name"].as(String)
-                       res[name] = new Branch.from_json(api, self, obj)
-               end
-               return res
-       end
-
-       # List of issues associated with their ids.
-       fun issues: Map[Int, Issue] do
-               api.message(1, "Get issues for {full_name}")
-               var res = new HashMap[Int, Issue]
-               var issue = last_issue
-               if issue == null then return res
-               res[issue.number] = issue
-               while issue.number > 1 do
-                       issue = api.load_issue(self, issue.number - 1)
-                       assert issue isa Issue
-                       res[issue.number] = issue
-               end
-               return res
-       end
-
-       # Search issues in this repo form an advanced query.
-       #
-       # Example:
-       #
-       # ~~~nitish
-       # var issues = repo.search_issues("is:open label:need_review")
-       # ~~~
-       #
-       # See <https://developer.github.com/v3/search/#search-issues>.
-       fun search_issues(query: String): nullable Array[Issue] do
-               query = "search/issues?q={query} repo:{full_name}"
-               var response = api.get(query)
-               if api.was_error then return null
-               var arr = response.as(JsonObject)["items"].as(JsonArray)
-               var res = new Array[Issue]
-               for obj in arr do
-                       res.add new Issue.from_json(api, self, obj.as(JsonObject))
-               end
-               return res
-       end
+       var owner: User is writable
 
-       # Get the last published issue.
-       fun last_issue: nullable Issue do
-               var array = api.get("repos/{full_name}/issues")
-               if not array isa JsonArray then return null
-               if array.is_empty then return null
-               var obj = array.first
-               if not obj isa JsonObject then return null
-               return new Issue.from_json(api, self, obj)
-       end
-
-       # List of labels associated with their names.
-       fun labels: Map[String, Label] do
-               api.message(1, "Get labels for {full_name}")
-               var array = api.get("repos/{full_name}/labels")
-               var res = new HashMap[String, Label]
-               if not array isa JsonArray then return res
-               for obj in array do
-                       if not obj isa JsonObject then continue
-                       var name = obj["name"].as(String)
-                       res[name] = new Label.from_json(api, self, obj)
-               end
-               return res
-       end
-
-       # List of milestones associated with their ids.
-       fun milestones: Map[Int, Milestone] do
-               api.message(1, "Get milestones for {full_name}")
-               var array = api.get("repos/{full_name}/milestones")
-               var res = new HashMap[Int, Milestone]
-               if array isa JsonArray then
-                       for obj in array do
-                               if not obj isa JsonObject then continue
-                               var number = obj["number"].as(Int)
-                               res[number] = new Milestone.from_json(api, self, obj)
-                       end
-               end
-               return res
-       end
-
-       # List of pull-requests associated with their ids.
-       #
-       # Implementation notes: because PR numbers are not consecutive,
-       # PR are loaded from pages.
-       # See: https://developer.github.com/v3/pulls/#list-pull-requests
-       fun pulls: Map[Int, PullRequest] do
-               api.message(1, "Get pulls for {full_name}")
-               var res = new HashMap[Int, PullRequest]
-               var page = 1
-               var array = api.get("{key}/pulls?page={page}").as(JsonArray)
-               while not array.is_empty do
-                       for obj in array do
-                               if not obj isa JsonObject then continue
-                               var number = obj["number"].as(Int)
-                               res[number] = new PullRequest.from_json(api, self, obj)
-                       end
-                       page += 1
-                       array = api.get("{key}/pulls?page={page}").as(JsonArray)
-               end
-               return res
-       end
-
-       # List of contributor related statistics.
-       fun contrib_stats: Array[ContributorStats] do
-               api.message(1, "Get contributor stats for {full_name}")
-               var res = new Array[ContributorStats]
-               var array = api.get("{key}/stats/contributors")
-               if array isa JsonArray then
-                       for obj in array do
-                               res.add new ContributorStats.from_json(api, obj.as(JsonObject))
-                       end
-               end
-               return res
-       end
-
-       # Repo default branch.
-       fun default_branch: Branch do
-               var name = json["default_branch"].as(String)
-               var branch = api.load_branch(self, name)
-               assert branch isa Branch
-               return branch
-       end
-
-       # Set the default branch
-       fun default_branch=(branch: Branch) do json["default_branch"] = branch.json
-end
-
-# A `RepoEntity` is something contained in a `Repo`.
-abstract class RepoEntity
-       super GithubEntity
-
-       # Repo that contains `self`.
-       var repo: Repo
-
-       # Init `self` from a `json` object.
-       init from_json(api: GithubAPI, repo: Repo, json: JsonObject) do
-               self.api = api
-               self.repo = repo
-               self.json = json
-       end
+       # Repo default branch name.
+       var default_branch: String is writable
 end
 
 # A Github branch.
@@ -569,44 +598,14 @@ end
 #
 # See <https://developer.github.com/v3/repos/#list-branches>.
 class Branch
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/branches/{name}"
+       super GithubEntity
+       serialize
 
        # Branch name.
-       var name: String
-
-       redef init from_json(api, repo, json) do
-               self.name = json["name"].as(String)
-               super
-       end
+       var name: String is writable
 
        # Get the last commit of `self`.
-       fun commit: Commit do return new Commit.from_json(api, repo, json["commit"].as(JsonObject))
-
-       # Set the last commit
-       fun commit=(commit: Commit) do json["commit"] = commit.json
-
-       # List all commits in `self`.
-       #
-       # This can be long depending on the branch size.
-       # Commit are returned in an unspecified order.
-       fun commits: Array[Commit] do
-               var res = new Array[Commit]
-               var done = new HashSet[String]
-               var todos = new Array[Commit]
-               todos.add commit
-               while not todos.is_empty do
-                       var commit = todos.pop
-                       if done.has(commit.sha) then continue
-                       done.add commit.sha
-                       res.add commit
-                       for parent in commit.parents do
-                               todos.add parent
-                       end
-               end
-               return res
-       end
+       var commit: Commit is writable
 end
 
 # A Github commit.
@@ -615,103 +614,86 @@ end
 #
 # See <https://developer.github.com/v3/repos/commits/>.
 class Commit
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/commits/{sha}"
+       super GithubEntity
+       serialize
 
        # Commit SHA.
-       var sha: String
-
-       redef init from_json(api, repo, json) do
-               self.sha = json["sha"].as(String)
-               super
-       end
+       var sha: String is writable
 
        # Parent commits of `self`.
-       fun parents: Array[Commit] do
-               var res = new Array[Commit]
-               var parents = json.get_or_null("parents")
-               if not parents isa JsonArray then return res
-               for obj in parents do
-                       if not obj isa JsonObject then continue
-                       res.add(api.load_commit(repo, obj["sha"].as(String)).as(not null))
-               end
-               return res
-       end
-
-       # Set parent commits.
-       fun parents=(parents: Array[Commit]) do
-               var res = new JsonArray
-               for parent in parents do res.add parent.json
-               json["parents"] = res
-       end
+       var parents: nullable Array[Commit] = null is writable
 
        # Author of the commit.
-       fun author: nullable User do
-               var user = json.get_or_null("author")
-               if user isa JsonObject then return new User.from_json(api, user)
-               return null
-       end
-
-       # Set commit author.
-       fun author=(user: nullable User) do
-               if user == null then
-                       json["author"] = null
-               else
-                       json["author"] = user.json
-               end
-       end
+       var author: nullable GitUser is writable
 
        # Committer of the commit.
-       fun committer: nullable User do
-               var user = json.get_or_null("author")
-               if user isa JsonObject then return new User.from_json(api, user)
-               return null
-       end
+       var committer: nullable GitUser is writable
 
-       # Set commit committer.
-       fun committer=(user: nullable User) do
-               if user == null then
-                       json["committer"] = null
-               else
-                       json["committer"] = user.json
-               end
-       end
+       # Authoring date as String.
+       var author_date: nullable String is writable
 
        # Authoring date as ISODate.
-       fun author_date: ISODate do
-               var commit = json["commit"].as(JsonObject)
-               var author = commit["author"].as(JsonObject)
-               return new ISODate.from_string(author["date"].as(String))
+       fun iso_author_date: nullable ISODate do
+               var author_date = self.author_date
+               if author_date == null then return null
+               return new ISODate.from_string(author_date)
        end
 
+       # Commit date as String.
+       var commit_date: nullable String is writable
+
        # Commit date as ISODate.
-       fun commit_date: ISODate do
-               var commit = json["commit"].as(JsonObject)
-               var author = commit["committer"].as(JsonObject)
-               return new ISODate.from_string(author["date"].as(String))
+       fun iso_commit_date: nullable ISODate do
+               var commit_date = self.commit_date
+               if commit_date == null then return null
+               return new ISODate.from_string(commit_date)
        end
 
        # List files staged in this commit.
-       fun files: Array[GithubFile] do
-               var res = new Array[GithubFile]
-               var files = json.get_or_null("files")
-               if not files isa JsonArray then return res
-               for obj in files do
-                       res.add(new GithubFile(obj.as(JsonObject)))
-               end
-               return res
-       end
+       var files: nullable Array[GithubFile] = null is optional, writable
 
-       # Set commit files.
-       fun files=(files: Array[GithubFile]) do
-               var res = new JsonArray
-               for file in files do res.add file.json
-               json["files"] = res
-       end
+       # Commit message.
+       var message: nullable String is writable
+
+       # Git commit representation linked to this commit.
+       var commit: nullable GitCommit
+end
+
+# A Git Commit representation
+class GitCommit
+       super GithubEntity
+       serialize
+
+       # Commit SHA.
+       var sha: nullable String is writable
+
+       # Parent commits of `self`.
+       var parents: nullable Array[GitCommit] = null is writable
+
+       # Author of the commit.
+       var author: nullable GitUser is writable
+
+       # Committer of the commit.
+       var committer: nullable GitUser is writable
 
        # Commit message.
-       fun message: String do return json["commit"].as(JsonObject)["message"].as(String)
+       var message: nullable String is writable
+end
+
+# Git user authoring data
+class GitUser
+       super GithubEntity
+       serialize
+
+       # Authoring date.
+       var date: nullable String = null is writable
+
+       # Authoring date as ISODate.
+       fun iso_date: nullable ISODate do
+               var date = self.date
+               if date == null then return null
+               return new ISODate.from_string(date)
+       end
 end
 
 # A Github issue.
@@ -720,210 +702,75 @@ end
 #
 # See <https://developer.github.com/v3/issues/>.
 class Issue
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/issues/{number}"
+       super GithubEntity
+       serialize
 
        # Issue Github ID.
-       var number: Int
-
-       redef init from_json(api, repo, json) do
-               self.number = json["number"].as(Int)
-               super
-       end
+       var number: Int is writable
 
        # Issue id.
-       fun id: Int do return json["id"].as(Int)
-
-       # Set issue id.
-       fun id=(id: Int) do json["id"] = id
+       var id: nullable Int is writable
 
        # Issue title.
-       fun title: String do return json["title"].as(String)
-
-       # Set issue title
-       fun title=(title: String) do json["title"] = title
+       var title: String is writable
 
        # User that created this issue.
-       fun user: User do return new User.from_json(api, json["user"].as(JsonObject))
-
-       # Set issue creator.
-       fun user=(user: User) do json["user"] = user.json
+       var user: nullable User is writable
 
        # List of labels on this issue associated to their names.
-       fun labels: Map[String, Label] do
-               var res = new HashMap[String, Label]
-               var lbls = json.get_or_null("labels")
-               if not lbls isa JsonArray then return res
-               for obj in lbls do
-                       if not obj isa JsonObject then continue
-                       var name = obj["name"].as(String)
-                       res[name] = new Label.from_json(api, repo, obj)
-               end
-               return res
-       end
+       var labels: nullable Array[Label] is writable
 
        # State of the issue on Github.
-       fun state: String do return json["state"].as(String)
-
-       # Set the state of this issue.
-       fun state=(state: String) do json["state"] = state
+       var state: String is writable
 
        # Is the issue locked?
-       fun locked: Bool do return json["locked"].as(Bool)
-
-       # Set issue locked state.
-       fun locked=(locked: Bool) do json["locked"] = locked
+       var locked: nullable Bool is writable
 
        # Assigned `User` (if any).
-       fun assignee: nullable User do
-               var assignee = json.get_or_null("assignee")
-               if assignee isa JsonObject then return new User.from_json(api, assignee)
-               return null
-       end
-
-       # Set issue assignee.
-       fun assignee=(user: nullable User) do
-               if user == null then
-                       json["assignee"] = null
-               else
-                       json["assignee"] = user.json
-               end
-       end
+       var assignee: nullable User is writable
 
        # `Milestone` (if any).
-       fun milestone: nullable Milestone do
-               var milestone = json.get_or_null("milestone")
-               if milestone isa JsonObject then return new Milestone.from_json(api, repo, milestone)
-               return null
-       end
-
-       # Set issue milestone.
-       fun milestone=(milestone: nullable Milestone) do
-               if milestone == null then
-                       json["milestone"] = null
-               else
-                       json["milestone"] = milestone.json
-               end
-       end
-
-       # List of comments made on this issue.
-       fun comments: Array[IssueComment] do
-               var res = new Array[IssueComment]
-               var count = comments_count
-               var page = 1
-               var array = api.get("{key}/comments?page={page}")
-               if not array isa JsonArray then
-                       return res
-               end
-               while not array.is_empty and res.length < count do
-                       for obj in array do
-                               if not obj isa JsonObject then continue
-                               var id = obj["id"].as(Int)
-                               var comment = api.load_issue_comment(repo, id)
-                               if comment == null then continue
-                               res.add(comment)
-                       end
-                       page += 1
-                       var json = api.get("{key}/comments?page={page}")
-                       if not json isa JsonArray then
-                               return res
-                       end
-                       array = json
-               end
-               return res
-       end
+       var milestone: nullable Milestone is writable
 
        # Number of comments on this issue.
-       fun comments_count: Int do return json["comments"].as(Int)
+       var comments: nullable Int is writable
 
-       # Creation time in ISODate format.
-       fun created_at: ISODate do return new ISODate.from_string(json["created_at"].as(String))
+       # Creation time as String.
+       var created_at: String is writable
 
-       # Set issue creation time.
-       fun created_at=(created_at: nullable ISODate) do
-               if created_at == null then
-                       json["created_at"] = null
-               else
-                       json["created_at"] = created_at.to_s
-               end
+       # Creation time as ISODate.
+       fun iso_created_at: ISODate do
+               return new ISODate.from_string(created_at)
        end
 
-       # Last update time in ISODate format (if any).
-       fun updated_at: nullable ISODate do
-               var res = json.get_or_null("updated_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
+       # Last update time as String (if any).
+       var updated_at: nullable String is writable
 
-       # Set issue last update time.
-       fun updated_at=(updated_at: nullable ISODate) do
-               if updated_at == null then
-                       json["updated_at"] = null
-               else
-                       json["updated_at"] = updated_at.to_s
-               end
+       # Last update date as ISODate.
+       fun iso_updated_at: nullable ISODate do
+               var updated_at = self.updated_at
+               if updated_at == null then return null
+               return new ISODate.from_string(updated_at)
        end
 
-       # Close time in ISODate format (if any).
-       fun closed_at: nullable ISODate do
-               var res = json.get_or_null("closed_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
+       # Close time as String (if any).
+       var closed_at: nullable String is writable
 
-       # Set issue close time.
-       fun closed_at=(closed_at: nullable ISODate) do
-               if closed_at == null then
-                       json["closed_at"] = null
-               else
-                       json["closed_at"] = closed_at.to_s
-               end
+       # Close time as ISODate.
+       fun iso_closed_at: nullable ISODate do
+               var closed_at = self.closed_at
+               if closed_at == null then return null
+               return new ISODate.from_string(closed_at)
        end
 
-       # TODO link to pull request
-
        # Full description of the issue.
-       fun body: String do return json["body"].as(String)
-
-       # Set description body
-       fun body=(body: String) do json["body"] = body
-
-       # List of events on this issue.
-       fun events: Array[IssueEvent] do
-               var res = new Array[IssueEvent]
-               var page = 1
-               var array = api.get("{key}/events?page={page}")
-               if not array isa JsonArray then return res
-               while not array.is_empty do
-                       for obj in array do
-                               if not obj isa JsonObject then continue
-                               res.add new IssueEvent.from_json(api, repo, obj)
-                       end
-                       page += 1
-                       array = api.get("{key}/events?page={page}").as(JsonArray)
-               end
-               return res
-       end
+       var body: nullable String is writable
 
        # User that closed this issue (if any).
-       fun closed_by: nullable User do
-               var closer = json.get_or_null("closed_by")
-               if closer isa JsonObject then return new User.from_json(api, closer)
-               return null
-       end
-
-       # Set user that closed the issue.
-       fun closed_by=(user: nullable User) do
-               if user == null then
-                       json["closed_by"] = null
-               else
-                       json["closed_by"] = user.json
-               end
-       end
+       var closed_by: nullable User is writable
 
        # Is this issue linked to a pull request?
-       fun is_pull_request: Bool do return json.has_key("pull_request")
+       var is_pull_request: Bool = false is writable
 end
 
 # A Github pull request.
@@ -934,158 +781,80 @@ end
 # See <https://developer.github.com/v3/pulls/>.
 class PullRequest
        super Issue
+       serialize
 
-       redef var key is lazy do return "{repo.key}/pulls/{number}"
+       # Merge time as String (if any).
+       var merged_at: nullable String is writable
 
-       # Merge time in ISODate format (if any).
-       fun merged_at: nullable ISODate do
-               var res = json.get_or_null("merged_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
-
-       # Set pull request merge time.
-       fun merged_at=(merged_at: nullable ISODate) do
-               if merged_at == null then
-                       json["merged_at"] = null
-               else
-                       json["merged_at"] = merged_at.to_s
-               end
+       # Merge time as ISODate.
+       fun iso_merged_at: nullable ISODate do
+               var merged_at = self.merged_at
+               if merged_at == null then return null
+               return new ISODate.from_string(merged_at)
        end
 
        # Merge commit SHA.
-       fun merge_commit_sha: String do return json["merge_commit_sha"].as(String)
-
-       # Set merge_commit_sha
-       fun merge_commit_sha=(sha: String) do json["merge_commit_sha"] = sha
+       var merge_commit_sha: nullable String is writable
 
        # Count of comments made on the pull request diff.
-       fun review_comments: Int do return json["review_comments"].as(Int)
-
-       # Set review_comments
-       fun review_comments=(count: Int) do json["review_comments"] = count
+       var review_comments: Int is writable
 
        # Pull request head (can be a commit SHA or a branch name).
-       fun head: PullRef do
-               var json = json["head"].as(JsonObject)
-               return new PullRef(api, json)
-       end
-
-       # Set head
-       fun head=(head: PullRef) do json["head"] = head.json
+       var head: PullRef is writable
 
        # Pull request base (can be a commit SHA or a branch name).
-       fun base: PullRef do
-               var json = json["base"].as(JsonObject)
-               return new PullRef(api, json)
-       end
-
-       # Set base
-       fun base=(base: PullRef) do json["base"] = base.json
+       var base: PullRef is writable
 
        # Is this pull request merged?
-       fun merged: Bool do return json["merged"].as(Bool)
-
-       # Set merged
-       fun merged=(merged: Bool) do json["merged"] = merged
+       var merged: Bool is writable
 
        # Is this pull request mergeable?
-       fun mergeable: Bool do return json["mergeable"].as(Bool)
-
-       # Set mergeable
-       fun mergeable=(mergeable: Bool) do json["mergeable"] = mergeable
+       var mergeable: nullable Bool is writable
 
        # Mergeable state of this pull request.
        #
        # See <https://developer.github.com/v3/pulls/#list-pull-requests>.
-       fun mergeable_state: Int do return json["mergeable_state"].as(Int)
-
-       # Set mergeable_state
-       fun mergeable_state=(mergeable_state: Int) do json["mergeable_state"] = mergeable_state
+       var mergeable_state: String is writable
 
        # User that merged this pull request (if any).
-       fun merged_by: nullable User do
-               var merger = json.get_or_null("merged_by")
-               if merger isa JsonObject then return new User.from_json(api, merger)
-               return null
-       end
-
-       # Set merged_by.
-       fun merged_by=(merged_by: nullable User) do
-               if merged_by == null then
-                       json["merged_by"] = null
-               else
-                       json["merged_by"] = merged_by.json
-               end
-       end
+       var merged_by: nullable User is writable
 
        # Count of commits in this pull request.
-       fun commits: Int do return json["commits"].as(Int)
-
-       # Set commits
-       fun commits=(commits: Int) do json["commits"] = commits
+       var commits: Int is writable
 
        # Added line count.
-       fun additions: Int do return json["additions"].as(Int)
-
-       # Set additions
-       fun additions=(additions: Int) do json["additions"] = additions
+       var additions: Int is writable
 
        # Deleted line count.
-       fun deletions: Int do return json["deletions"].as(Int)
-
-       # Set deletions
-       fun deletions=(deletions: Int) do json["deletions"] = deletions
+       var deletions: Int is writable
 
        # Changed files count.
-       fun changed_files: Int do return json["changed_files"].as(Int)
+       var changed_files: Int is writable
 
-       # Set changed_files
-       fun changed_files=(changed_files: Int) do json["changed_files"] = changed_files
+       # URL to patch file
+       var patch_url: nullable String is writable
 end
 
 # A pull request reference (used for head and base).
 class PullRef
-
-       # Api instance that maintains self.
-       var api: GithubAPI
-
-       # JSON representation.
-       var json: JsonObject
+       serialize
 
        # Label pointed by `self`.
-       fun labl: String do return json["label"].as(String)
-
-       # Set labl
-       fun labl=(labl: String) do json["label"] = labl
+       var labl: String is writable, serialize_as("label")
 
        # Reference pointed by `self`.
-       fun ref: String do return json["ref"].as(String)
-
-       # Set ref
-       fun ref=(ref: String) do json["ref"] = ref
+       var ref: String is writable
 
        # Commit SHA pointed by `self`.
-       fun sha: String do return json["sha"].as(String)
-
-       # Set sha
-       fun sha=(sha: String) do json["sha"] = sha
+       var sha: String is writable
 
        # User pointed by `self`.
-       fun user: User do
-               return new User.from_json(api, json["user"].as(JsonObject))
-       end
-
-       # Set user
-       fun user=(user: User) do json["user"] = user.json
+       var user: User is writable
 
-       # Repo pointed by `self`.
-       fun repo: Repo do
-               return new Repo.from_json(api, json["repo"].as(JsonObject))
-       end
-
-       # Set repo
-       fun repo=(repo: Repo) do json["repo"] = repo.json
+       # Repo pointed by `self` (if any).
+       #
+       # A `null` value means the `repo` was deleted.
+       var repo: nullable Repo is writable
 end
 
 # A Github label.
@@ -1094,23 +863,14 @@ end
 #
 # See <https://developer.github.com/v3/issues/labels/>.
 class Label
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/labels/{name}"
+       super GithubEntity
+       serialize
 
        # Label name.
-       var name: String
-
-       redef init from_json(api, repo, json) do
-               self.name = json["name"].as(String)
-               super
-       end
+       var name: String is writable
 
        # Label color code.
-       fun color: String do return json["color"].as(String)
-
-       # Set color
-       fun color=(color: String) do json["color"] = color
+       var color: String is writable
 end
 
 # A Github milestone.
@@ -1119,110 +879,68 @@ end
 #
 # See <https://developer.github.com/v3/issues/milestones/>.
 class Milestone
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/milestones/{number}"
+       super GithubEntity
+       serialize
 
        # The milestone id on Github.
-       var number: Int
-
-       redef init from_json(api, repo, json) do
-               super
-               self.number = json["number"].as(Int)
-       end
+       var number: nullable Int = null is writable
 
        # Milestone title.
-       fun title: String do return json["title"].as(String)
-
-       # Set title
-       fun title=(title: String) do json["title"] = title
+       var title: String is writable
 
        # Milestone long description.
-       fun description: String do return json["description"].as(String)
-
-       # Set description
-       fun description=(description: String) do json["description"] = description
+       var description: nullable String is writable
 
        # Count of opened issues linked to this milestone.
-       fun open_issues: Int do return json["open_issues"].as(Int)
-
-       # Set open_issues
-       fun open_issues=(open_issues: Int) do json["open_issues"] = open_issues
+       var open_issues: nullable Int = null is writable
 
        # Count of closed issues linked to this milestone.
-       fun closed_issues: Int do return json["closed_issues"].as(Int)
-
-       # Set closed_issues
-       fun closed_issues=(closed_issues: Int) do json["closed_issues"] = closed_issues
+       var closed_issues: nullable Int = null is writable
 
        # Milestone state.
-       fun state: String do return json["state"].as(String)
+       var state: nullable String is writable
 
-       # Set state
-       fun state=(state: String) do json["state"] = state
+       # Creation time as String.
+       var created_at: nullable String is writable
 
-       # Creation time in ISODate format.
-       fun created_at: ISODate do
-               return new ISODate.from_string(json["created_at"].as(String))
+       # Creation time as ISODate.
+       fun iso_created_at: nullable ISODate do
+               var created_at = self.created_at
+               if created_at == null then return null
+               return new ISODate.from_string(created_at)
        end
 
-       # Set created_at
-       fun created_at=(created_at: ISODate) do json["created_at"] = created_at.to_s
-
        # User that created this milestone.
-       fun creator: User do
-               return new User.from_json(api, json["creator"].as(JsonObject))
-       end
+       var creator: nullable User is writable
 
-       # Set creator
-       fun creator=(creator: User) do json["creator"] = creator.json
+       # Due time as String (if any).
+       var due_on: nullable String is writable
 
        # Due time in ISODate format (if any).
-       fun due_on: nullable ISODate do
-               var res = json.get_or_null("updated_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
+       fun iso_due_on: nullable ISODate do
+               var due_on = self.due_on
+               if due_on == null then return null
+               return new ISODate.from_string(due_on)
        end
 
-       # Set due_on.
-       fun due_on=(due_on: nullable ISODate) do
-               if due_on == null then
-                       json["due_on"] = null
-               else
-                       json["due_on"] = due_on.to_s
-               end
-       end
-
-       # Update time in ISODate format (if any).
-       fun updated_at: nullable ISODate do
-               var res = json.get_or_null("updated_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
+       # Last update time as String (if any).
+       var updated_at: nullable String is writable
 
-       # Set updated_at.
-       fun updated_at=(updated_at: nullable ISODate) do
-               if updated_at == null then
-                       json["updated_at"] = null
-               else
-                       json["updated_at"] = updated_at.to_s
-               end
+       # Last update date as ISODate.
+       fun iso_updated_at: nullable ISODate do
+               var updated_at = self.updated_at
+               if updated_at == null then return null
+               return new ISODate.from_string(updated_at)
        end
 
-       # Close time in ISODate format (if any).
-       fun closed_at: nullable ISODate do
-               var res = json.get_or_null("closed_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
+       # Close time as String (if any).
+       var closed_at: nullable String is writable
 
-       # Set closed_at.
-       fun closed_at=(closed_at: nullable ISODate) do
-               if closed_at == null then
-                       json["closed_at"] = null
-               else
-                       json["closed_at"] = closed_at.to_s
-               end
+       # Close time as ISODate.
+       fun iso_closed_at: nullable ISODate do
+               var closed_at = self.closed_at
+               if closed_at == null then return null
+               return new ISODate.from_string(closed_at)
        end
 end
 
@@ -1234,57 +952,38 @@ end
 # * `IssueComment` are made on an issue or pull request page.
 # * `ReviewComment` are made on the diff associated to a pull request.
 abstract class Comment
-       super RepoEntity
+       super GithubEntity
+       serialize
 
        # Identifier of this comment.
-       var id: Int
-
-       redef init from_json(api, repo, json) do
-               self.id = json["id"].as(Int)
-               super
-       end
+       var id: Int is writable
 
        # User that made this comment.
-       fun user: User do
-               return new User.from_json(api, json["user"].as(JsonObject))
-       end
+       var user: User is writable
 
-       # Set user
-       fun user=(user: User) do json["user"] = user.json
+       # Creation time as String.
+       var created_at: String is writable
 
-       # Creation time in ISODate format.
-       fun created_at: ISODate do
-               return new ISODate.from_string(json["created_at"].as(String))
+       # Creation time as ISODate.
+       fun iso_created_at: nullable ISODate do
+               return new ISODate.from_string(created_at)
        end
 
-       # Set created_at
-       fun created_at=(created_at: ISODate) do json["created_at"] = created_at.to_s
+       # Last update time as String (if any).
+       var updated_at: nullable String is writable
 
-       # Last update time in ISODate format (if any).
-       fun updated_at: nullable ISODate do
-               var res = json.get_or_null("updated_at")
-               if res isa String then return new ISODate.from_string(res)
-               return null
-       end
-
-       # Set updated_at.
-       fun updated_at=(updated_at: nullable ISODate) do
-               if updated_at == null then
-                       json["updated_at"] = null
-               else
-                       json["updated_at"] = updated_at.to_s
-               end
+       # Last update date as ISODate.
+       fun iso_updated_at: nullable ISODate do
+               var updated_at = self.updated_at
+               if updated_at == null then return null
+               return new ISODate.from_string(updated_at)
        end
 
        # Comment body text.
-       fun body: String do return json["body"].as(String)
-
-       # Set body
-       fun body=(body: String) do json["body"] = body
+       var body: String is writable
 
        # Does the comment contain an acknowledgement (+1)
-       fun is_ack: Bool
-       do
+       fun is_ack: Bool do
                return body.has("\\+1\\b".to_re) or body.has(":+1:") or body.has(":shipit:")
        end
 end
@@ -1292,42 +991,19 @@ end
 # A comment made on a commit.
 class CommitComment
        super Comment
-
-       redef var key is lazy do return "{repo.key}/comments/{id}"
+       serialize
 
        # Commented commit.
-       fun commit: Commit do
-               return api.load_commit(repo, json["commit_id"].as(String)).as(not null)
-       end
-
-       # Set commit
-       fun commit=(commit: Commit) do json["commit_id"] = commit.json
+       var commit_id: String is writable
 
        # Position of the comment on the line.
-       fun position: nullable String do
-               var res = json.get_or_null("position")
-               if res isa String then return res
-               return null
-       end
-
-       # Set position.
-       fun position=(position: nullable String) do json["position"] = position
+       var position: nullable Int is writable
 
        # Line of the comment.
-       fun line: nullable String do
-               var res = json.get_or_null("line")
-               if res isa String then return res
-               return null
-       end
-
-       # Set line.
-       fun line=(line: nullable String) do json["line"] = line
+       var line: nullable Int is writable
 
        # Path of the commented file.
-       fun path: String do return json["path"].as(String)
-
-       # Set path.
-       fun path=(path: String) do json["path"] = path
+       var path: nullable String is writable
 end
 
 # Comments made on Github issue and pull request pages.
@@ -1337,20 +1013,13 @@ end
 # See <https://developer.github.com/v3/issues/comments/>.
 class IssueComment
        super Comment
-
-       redef var key is lazy do return "{repo.key}/issues/comments/{id}"
+       serialize
 
        # Issue that contains `self`.
-       fun issue: Issue do
-               var number = issue_url.split("/").last.to_i
-               return api.load_issue(repo, number).as(not null)
-       end
+       fun issue_number: Int do return issue_url.split("/").last.to_i
 
        # Link to the issue document on API.
-       fun issue_url: String do return json["issue_url"].as(String)
-
-       # Set issue_url.
-       fun issue_url=(issue_url: String) do json["issue_url"] = issue_url
+       var issue_url: String is writable
 end
 
 # Comments made on Github pull request diffs.
@@ -1360,56 +1029,31 @@ end
 # See <https://developer.github.com/v3/pulls/comments/>.
 class ReviewComment
        super Comment
-
-       redef var key is lazy do return "{repo.key}/pulls/comments/{id}"
+       serialize
 
        # Pull request that contains `self`.
-       fun pull: PullRequest do
-               var number = pull_request_url.split("/").last.to_i
-               return api.load_pull(repo, number).as(not null)
-       end
+       fun pull_number: Int do return pull_request_url.split("/").last.to_i
 
        # Link to the pull request on API.
-       fun pull_request_url: String do return json["pull_request_url"].as(String)
-
-       # Set pull_request_url.
-       fun pull_request_url=(pull_request_url: String) do json["pull_request_url"] = pull_request_url
+       var pull_request_url: String is writable
 
        # Diff hunk.
-       fun diff_hunk: String do return json["diff_hunk"].as(String)
-
-       # Set diff_hunk.
-       fun diff_hunk=(diff_hunk: String) do json["diff_hunk"] = diff_hunk
+       var diff_hunk: String is writable
 
        # Path of commented file.
-       fun path: String do return json["path"].as(String)
-
-       # Set path.
-       fun path=(path: String) do json["path"] = path
+       var path: String is writable
 
        # Position of the comment on the file.
-       fun position: Int do return json["position"].as(Int)
-
-       # Set position.
-       fun position=(position: Int) do json["position"] = position
+       var position: nullable Int is writable
 
        # Original position in the diff.
-       fun original_position: Int do return json["original_position"].as(Int)
-
-       # Set original_position.
-       fun original_position=(original_position: Int) do json["original_position"] = original_position
+       var original_position: Int is writable
 
        # Commit referenced by this comment.
-       fun commit_id: String do return json["commit_id"].as(String)
-
-       # Set commit_id.
-       fun commit_id=(commit_id: String) do json["commit_id"] = commit_id
+       var commit_id: String is writable
 
        # Original commit id.
-       fun original_commit_id: String do return json["original_commit_id"].as(String)
-
-       # Set original_commit_id.
-       fun original_commit_id=(commit_id: String) do json["original_commit_id"] = commit_id
+       var original_commit_id: String is writable
 end
 
 # An event that occurs on a Github `Issue`.
@@ -1418,183 +1062,74 @@ end
 #
 # See <https://developer.github.com/v3/issues/events/>.
 class IssueEvent
-       super RepoEntity
-
-       redef var key is lazy do return "{repo.key}/issues/events/{id}"
+       super GithubEntity
+       serialize
 
        # Event id on Github.
-       var id: Int
-
-       redef init from_json(api, repo, json) do
-               self.id = json["id"].as(Int)
-               super
-       end
-
-       # Issue that contains `self`.
-       fun issue: Issue do
-               return new Issue.from_json(api, repo, json["issue"].as(JsonObject))
-       end
-
-       # Set issue.
-       fun issue=(issue: Issue) do json["issue"] = issue.json
+       var id: Int is writable
 
        # User that initiated the event.
-       fun actor: User do
-               return new User.from_json(api, json["actor"].as(JsonObject))
-       end
+       var actor: User is writable
 
-       # Set actor.
-       fun actor=(actor: User) do json["actor"] = actor.json
+       # Creation time as String.
+       var created_at: String is writable
 
-       # Creation time in ISODate format.
-       fun created_at: ISODate do
-               return new ISODate.from_string(json["created_at"].as(String))
+       # Creation time as ISODate.
+       fun iso_created_at: nullable ISODate do
+               return new ISODate.from_string(created_at)
        end
 
-       # Set created_at.
-       fun created_at=(created_at: ISODate) do json["created_at"] = created_at.to_s
-
        # Event descriptor.
-       fun event: String do return json["event"].as(String)
-
-       # Set event.
-       fun event=(event: String) do json["event"] = event
+       var event: String is writable
 
        # Commit linked to this event (if any).
-       fun commit_id: nullable String do
-               var res = json.get_or_null("commit_id")
-               if res isa String then return res
-               return null
-       end
-
-       # Set commit_id.
-       fun commit_id=(commit_id: nullable String) do json["commit_id"] = commit_id
+       var commit_id: nullable String is writable
 
        # Label linked to this event (if any).
-       fun labl: nullable Label do
-               var res = json.get_or_null("label")
-               if res isa JsonObject then return new Label.from_json(api, repo, res)
-               return null
-       end
-
-       # Set labl.
-       fun labl=(labl: nullable Label) do
-               if labl == null then
-                       json["labl"] = null
-               else
-                       json["labl"] = labl.json
-               end
-       end
+       var labl: nullable Label is writable, serialize_as("label")
 
        # User linked to this event (if any).
-       fun assignee: nullable User do
-               var res = json.get_or_null("assignee")
-               if res isa JsonObject then return new User.from_json(api, res)
-               return null
-       end
-
-       # Set assignee.
-       fun assignee=(assignee: nullable User) do
-               if assignee == null then
-                       json["assignee"] = null
-               else
-                       json["assignee"] = assignee.json
-               end
-       end
+       var assignee: nullable User is writable
 
        # Milestone linked to this event (if any).
-       fun milestone: nullable Milestone do
-               var res = json.get_or_null("milestone")
-               if res isa JsonObject then return new Milestone.from_json(api, repo, res)
-               return null
-       end
-
-       # Set milestone.
-       fun milestone=(milestone: nullable User) do
-               if milestone == null then
-                       json["milestone"] = null
-               else
-                       json["milestone"] = milestone.json
-               end
-       end
+       var milestone: nullable Milestone is writable
 
        # Rename linked to this event (if any).
-       fun rename: nullable RenameAction do
-               var res = json.get_or_null("rename")
-               if res isa JsonObject then return new RenameAction(res)
-               return null
-       end
-
-       # Set rename.
-       fun rename=(rename: nullable User) do
-               if rename == null then
-                       json["rename"] = null
-               else
-                       json["rename"] = rename.json
-               end
-       end
+       var rename: nullable RenameAction is writable
 end
 
 # A rename action maintains the name before and after a renaming action.
 class RenameAction
-
-       # JSON content.
-       var json: JsonObject
+       serialize
 
        # Name before renaming.
-       fun from: String do return json["from"].as(String)
-
-       # Set from.
-       fun from=(from: String) do json["from"] = from
+       var from: String is writable
 
        # Name after renaming.
-       fun to: String do return json["to"].as(String)
-
-       # Set to.
-       fun to=(to: String) do json["to"] = to
+       var to: String is writable
 end
 
-# Contributors list with additions, deletions, and commit counts.
 #
 # Should be accessed from `Repo::contrib_stats`.
 #
 # See <https://developer.github.com/v3/repos/statistics/>.
 class ContributorStats
        super Comparable
+       serialize
 
        redef type OTHER: ContributorStats
 
        # Github API client.
-       var api: GithubAPI
-
-       # Json content.
-       var json: JsonObject
-
-       # Init `self` from a `json` object.
-       init from_json(api: GithubAPI, json: JsonObject) do
-               self.api = api
-               self.json = json
-       end
+       var api: GithubAPI is writable
 
        # User these statistics are about.
-       fun author: User do
-               return new User.from_json(api, json["author"].as(JsonObject))
-       end
-
-       # Set author.
-       fun author=(author: User) do json["author"] = author.json
+       var author: User is writable
 
        # Total number of commit.
-       fun total: Int do return json["total"].as(Int)
-
-       # Set total.
-       fun total=(total: Int) do json["total"] = total
+       var total: Int is writable
 
        # Are of weeks of activity with detailed statistics.
-       fun weeks: JsonArray do return json["weeks"].as(JsonArray)
-
-       # Set weeks.
-       fun weeks=(weeks: JsonArray) do json["weeks"] = weeks
+       var weeks: JsonArray is writable
 
        # ContributorStats can be compared on the total amount of commits.
        redef fun <(o) do return total < o.total
@@ -1604,13 +1139,69 @@ end
 #
 # Mostly a wrapper around a json object.
 class GithubFile
-
-       # Json content.
-       var json: JsonObject
+       serialize
 
        # File name.
-       fun filename: String do return json["filename"].as(String)
+       var filename: String is writable
+end
+
+# Make ISO Datew serilizable
+redef class ISODate
+       serialize
+end
 
-       # Set filename.
-       fun filename=(filename: String) do json["filename"] = filename
+# JsonDeserializer specific for Github objects.
+class GithubDeserializer
+       super JsonDeserializer
+
+       redef fun class_name_heuristic(json_object) do
+               if json_object.has_key("login") then
+                       return "User"
+               else if json_object.has_key("full_name") then
+                       return "Repo"
+               else if json_object.has_key("name") and json_object.has_key("commit") then
+                       return "Branch"
+               else if json_object.has_key("sha") and json_object.has_key("ref") then
+                       return "PullRef"
+               else if (json_object.has_key("sha") and json_object.has_key("commit")) or (json_object.has_key("id") and json_object.has_key("tree_id")) then
+                       return "Commit"
+               else if json_object.has_key("sha") and json_object.has_key("tree") then
+                       return "GitCommit"
+               else if json_object.has_key("name") and json_object.has_key("date") then
+                       return "GitUser"
+               else if json_object.has_key("number") and json_object.has_key("patch_url") then
+                       return "PullRequest"
+               else if json_object.has_key("open_issues") and json_object.has_key("closed_issues") then
+                       return "Milestone"
+               else if json_object.has_key("number") and json_object.has_key("title") then
+                       return "Issue"
+               else if json_object.has_key("color") then
+                       return "Label"
+               else if json_object.has_key("event") then
+                       return "IssueEvent"
+               else if json_object.has_key("original_commit_id") then
+                       return "ReviewComment"
+               else if json_object.has_key("commit_id") then
+                       return "CommitComment"
+               else if json_object.has_key("issue_url") then
+                       return "IssueComment"
+               end
+               return null
+       end
+
+       redef fun deserialize_class(name) do
+               if name == "Issue" then
+                       var issue = super.as(Issue)
+                       if path.last.has_key("pull_request") then
+                               issue.is_pull_request = true
+                       end
+                       return issue
+               else if name == "Commit" then
+                       var commit = super.as(Commit)
+                       var git_commit = commit.commit
+                       if git_commit != null then commit.message = git_commit.message
+                       return commit
+               end
+               return super
+       end
 end