From: Alexandre Terrasa <alexandre@moz-code.org>
Date: Thu, 7 May 2015 05:42:31 +0000 (-0400)
Subject: contrib/nitiwiki: introduce wikilinks
X-Git-Tag: v0.7.5~30^2~7
X-Git-Url: http://nitlanguage.org

contrib/nitiwiki: introduce wikilinks

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
---

diff --git a/contrib/nitiwiki/src/wiki_links.nit b/contrib/nitiwiki/src/wiki_links.nit
index 9379c4d..bbbfea0 100644
--- a/contrib/nitiwiki/src/wiki_links.nit
+++ b/contrib/nitiwiki/src/wiki_links.nit
@@ -16,7 +16,76 @@
 module wiki_links
 
 import wiki_base
-import markdown
+intrude import markdown
+
+redef class Nitiwiki
+	# Looks up a WikiEntry by its `name`.
+	#
+	# Rules are:
+	# 1. Looks in the current section
+	# 2. Looks in the current section children
+	# 3. Looks in the current section parent
+	# 4. Looks up to wiki root
+	#
+	# Returns `null` if no article can be found.
+	fun lookup_entry_by_name(context: WikiEntry, name: String): nullable WikiEntry do
+		var section = context.parent
+		var res = section.lookup_entry_by_name(name)
+		if res != null then return res
+		while section != null do
+			if section.name == name then return section
+			if section.children.has_key(name) then return section.children[name]
+			section = section.parent
+		end
+		return null
+	end
+
+	# Looks up a WikiEntry by its `title`.
+	#
+	# Rules are:
+	# 1. Looks in the current section
+	# 2. Looks in the current section children
+	# 3. Looks in the current section parent
+	# 4. Looks up to wiki root
+	#
+	# Returns `null` if no article can be found.
+	fun lookup_entry_by_title(context: WikiEntry, title: String): nullable WikiEntry do
+		var section = context.parent
+		var res = section.lookup_entry_by_title(title)
+		if res != null then return res
+		while section != null do
+			if section.title == title then return section
+			for child in section.children.values do
+				if child.title == title then return child
+			end
+			section = section.parent
+		end
+		return null
+	end
+
+	# Looks up a WikiEntry by its `path`.
+	#
+	# Path can be relative from `context` like `context/entry`.
+	# Or absolute like `/entry1/entry2`.
+	#
+	# Returns `null` if no article can be found.
+	fun lookup_entry_by_path(context: WikiEntry, path: String): nullable WikiEntry do
+		var entry = context.parent
+		var parts = path.split_with("/")
+		if path.has_prefix("/") then
+			entry = root_section
+			if parts.is_empty then return root_section.index
+			parts.shift
+		end
+		while not parts.is_empty do
+			var name = parts.shift
+			if name.is_empty then continue
+			if not entry.children.has_key(name) then return null
+			entry = entry.children[name]
+		end
+		return entry
+	end
+end
 
 redef class WikiEntry
 
@@ -27,6 +96,28 @@ redef class WikiEntry
 		super
 		if not is_dirty and not wiki.force_render then return
 	end
+
+	# Search in `self` then `self.children` if an entry has the name `name`.
+	fun lookup_entry_by_name(name: String): nullable WikiEntry do
+		if children.has_key(name) then return children[name]
+		for child in children.values do
+			var res = child.lookup_entry_by_name(name)
+			if res != null then return res
+		end
+		return null
+	end
+
+	# Search in `self` then `self.children` if an entry has the title `title`.
+	fun lookup_entry_by_title(title: String): nullable WikiEntry do
+		for child in children.values do
+			if child.title == title then return child
+		end
+		for child in children.values do
+			var res = child.lookup_entry_by_title(title)
+			if res != null then return res
+		end
+		return null
+	end
 end
 
 redef class WikiSection
@@ -64,7 +155,7 @@ redef class WikiArticle
 	redef fun render do
 		super
 		if not is_dirty and not wiki.force_render or not has_source then return
-		var md_proc = new MarkdownProcessor
+		var md_proc = new NitiwikiMdProcessor(wiki, self)
 		content = md_proc.process(md.as(not null))
 		headlines.recover_with(md_proc.emitter.decorator.headlines)
 	end
@@ -81,3 +172,124 @@ class WikiSectionIndex
 
 	redef fun url do return section.url
 end
+
+# A MarkdownProcessor able to parse wiki links.
+class NitiwikiMdProcessor
+	super MarkdownProcessor
+
+	# Wiki used to resolve links.
+	var wiki: Nitiwiki
+
+	# Article parsed by `self`.
+	#
+	# Used to contextualize links.
+	var context: WikiArticle
+
+	init do
+		emitter = new MarkdownEmitter(self)
+		emitter.decorator = new NitiwikiDecorator(wiki, context)
+	end
+
+	redef fun token_at(text, pos) do
+		var token = super
+		if not token isa TokenLink then return token
+		if pos + 1 < text.length then
+			var c = text[pos + 1]
+			if c == '[' then return new TokenWikiLink(pos, c)
+		end
+		return token
+	end
+end
+
+private class NitiwikiDecorator
+	super HTMLDecorator
+
+	# Wiki used to resolve links.
+	var wiki: Nitiwiki
+
+	# Article used to contextualize links.
+	var context: WikiArticle
+
+	fun add_wikilink(v: MarkdownEmitter, link: Text, name, comment: nullable Text) do
+		var wiki = v.processor.as(NitiwikiMdProcessor).wiki
+		var target: nullable WikiEntry = null
+		var anchor: nullable String = null
+		if link.has("#") then
+			var parts = link.split_with("#")
+			link = parts.first
+			anchor = parts.subarray(1, parts.length - 1).join("#")
+		end
+		if link.has("/") then
+			target = wiki.lookup_entry_by_path(context, link.to_s)
+		else
+			target = wiki.lookup_entry_by_name(context, link.to_s)
+			if target == null then
+				target = wiki.lookup_entry_by_title(context, link.to_s)
+			end
+		end
+		v.add "<a "
+		if target != null then
+			if name == null then name = target.title
+			link = target.url
+		else
+			wiki.message("Warning: unknown wikilink `{link}` (in {context.src_path.as(not null)})", 0)
+			v.add "class=\"broken\" "
+		end
+		v.add "href=\""
+		append_value(v, link)
+		if anchor != null then append_value(v, "#{anchor}")
+		v.add "\""
+		if comment != null and not comment.is_empty then
+			v.add " title=\""
+			append_value(v, comment)
+			v.add "\""
+		end
+		v.add ">"
+		if name == null then name = link
+		v.emit_text(name)
+		v.add "</a>"
+	end
+end
+
+# A NitiWiki link token.
+#
+# Something of the form `[[foo]]`.
+#
+# Allowed formats:
+#
+# * `[[Wikilink]]`
+# * `[[Wikilink/Bar]]`
+# * `[[Wikilink#foo]]`
+# * `[[Wikilink/Bar#foo]]`
+# * `[[title|Wikilink]]`
+# * `[[title|Wikilink/Bar]]`
+# * `[[title|Wikilink/Bar#foo]]`
+class TokenWikiLink
+	super TokenLink
+
+	redef fun emit_hyper(v) do
+		v.decorator.as(NitiwikiDecorator).add_wikilink(v, link.as(not null), name, comment)
+	end
+
+	redef fun check_link(v, out, start, token) do
+		var md = v.current_text
+		var pos = start + 2
+		var tmp = new FlatBuffer
+		pos = md.read_md_link_id(tmp, pos)
+		if pos < start then return -1
+		var name = tmp.write_to_string
+		if name.has("|") then
+			var parts = name.split_once_on("|")
+			self.name = parts.first
+			self.link = parts[1]
+		else
+			self.name = null
+			self.link = name
+		end
+		pos += 1
+		pos = md.skip_spaces(pos)
+		if pos < start then return -1
+		pos += 1
+		return pos
+	end
+end