# See the License for the specific language governing permissions and
# limitations under the License.
-# Services to read JSON: `from_json_string` and `JsonDeserializer`
+# Services to read JSON: `deserialize_json` and `JsonDeserializer`
module serialization_read
-import ::serialization::caching
-private import ::serialization::engine_tools
+import serialization::caching
+private import serialization::engine_tools
+import serialization::safe
+
private import static
-private import string_parser
import poset
# Deserializer from a Json string.
class JsonDeserializer
super CachingDeserializer
+ super SafeDeserializer
# Json text to deserialize from.
private var text: Text
- # Accepted parameterized classes to deserialize
- #
- # If `whitelist.empty`, all types are accepted.
- #
- # ~~~nitish
- # import json::serialization
- #
- # class MyClass
- # serialize
- # end
- #
- # var json_string = """
- # {"__class" = "MyClass"}
- # """
- #
- # var deserializer = new JsonDeserializer(json_string)
- # var obj = deserializer.deserialize
- # assert deserializer.errors.is_empty
- # assert obj isa MyClass
- #
- # deserializer = new JsonDeserializer(json_string)
- # deserializer.whitelist.add "Array[String]"
- # deserializer.whitelist.add "AnotherAcceptedClass"
- # obj = deserializer.deserialize
- # assert deserializer.errors.length == 1
- # assert obj == null
- # ~~~
- var whitelist = new Array[Text]
-
# Root json object parsed from input text.
private var root: nullable Object is noinit
# ref?
if kind == "ref" then
if not object.keys.has("__id") then
- errors.add new Error("Serialization Error: JSON object reference does not declare a `__id`.")
+ errors.add new Error("Deserialization Error: JSON object reference does not declare a `__id`.")
return object
end
var id = object["__id"]
if not id isa Int then
- errors.add new Error("Serialization Error: JSON object reference declares a non-integer `__id`.")
+ errors.add new Error("Deserialization Error: JSON object reference declares a non-integer `__id`.")
return object
end
if not cache.has_id(id) then
- errors.add new Error("Serialization Error: JSON object reference has an unknown `__id`.")
+ errors.add new Error("Deserialization Error: JSON object reference has an unknown `__id`.")
return object
end
id = object["__id"]
if not id isa Int then
- errors.add new Error("Serialization Error: JSON object declaration declares a non-integer `__id`.")
+ errors.add new Error("Deserialization Error: JSON object declaration declares a non-integer `__id`.")
return object
end
if cache.has_id(id) then
- errors.add new Error("Serialization Error: JSON object with `__id` {id} is deserialized twice.")
+ errors.add new Error("Deserialization Error: JSON object with `__id` {id} is deserialized twice.")
# Keep going
end
end
if class_name == null and static_type != null then
# Fallack to the static type, strip the `nullable` prefix
- var prefix = "nullable "
- if static_type.has(prefix) then
- class_name = static_type.substring_from(prefix.length)
- else class_name = static_type
+ class_name = static_type.strip_nullable
end
end
if class_name == null then
- errors.add new Error("Serialization Error: JSON object declaration does not declare a `__class`.")
+ errors.add new Error("Deserialization Error: JSON object declaration does not declare a `__class`.")
return object
end
if not class_name isa String then
- errors.add new Error("Serialization Error: JSON object declaration declares a non-string `__class`.")
+ errors.add new Error("Deserialization Error: JSON object declaration declares a non-string `__class`.")
return object
end
- if whitelist.not_empty and not whitelist.has(class_name) then
- errors.add new Error("Deserialization Error: '{class_name}' not in whitelist")
- return null
- end
+ if not accept(class_name, static_type) then return null
# advance on path
path.push object
# char?
if kind == "char" then
if not object.keys.has("__val") then
- errors.add new Error("Serialization Error: JSON `char` object does not declare a `__val`.")
+ errors.add new Error("Deserialization Error: JSON `char` object does not declare a `__val`.")
return object
end
var val = object["__val"]
if not val isa String or val.is_empty then
- errors.add new Error("Serialization Error: JSON `char` object does not declare a single char in `__val`.")
+ errors.add new Error("Deserialization Error: JSON `char` object does not declare a single char in `__val`.")
return object
end
return val.chars.first
end
- errors.add new Error("Serialization Error: JSON object has an unknown `__kind`.")
+ # byte?
+ if kind == "byte" then
+ var val = object.get_or_null("__val")
+ if not val isa Int then
+ errors.add new Error("Serialization Error: JSON `byte` object does not declare an integer `__val`.")
+ return object
+ end
+
+ return val.to_b
+ end
+
+ errors.add new Error("Deserialization Error: JSON object has an unknown `__kind`.")
return object
end
if object isa Array[nullable Object] then
# Can we use the static type?
if static_type != null then
- var prefix = "nullable "
- var class_name = if static_type.has(prefix) then
- static_type.substring_from(prefix.length)
- else static_type
-
opened_array = object
- var value = deserialize_class(class_name)
+ var value = deserialize_class(static_type.strip_nullable)
opened_array = null
return value
end
return array
end
+ if object isa String and object.length == 1 and static_type == "Char" then
+ # Char serialized as a JSON string
+ return object.chars.first
+ end
+
+ if object isa Int and static_type == "Byte" then
+ # Byte serialized as an integer
+ return object.to_b
+ end
+
return object
end
# Current array open for deserialization, used by `SimpleCollection::from_deserializer`
private var opened_array: nullable Array[nullable Object] = null
- redef fun deserialize
+ redef fun deserialize(static_type)
do
errors.clear
- return convert_object(root)
+ return convert_object(root, static_type)
end
# User customizable heuristic to infer the name of the Nit class to deserialize `json_object`
# Deserialize a `nullable Object` from this JSON formatted string
#
+ # If a `static_type` is given, only subtypes of the `static_type` are accepted.
+ #
# Warning: Deserialization errors are reported with `print_error` and
# may be returned as a partial object or as `null`.
#
# This method is not appropriate when errors need to be handled programmatically,
# manually use a `JsonDeserializer` in such cases.
- fun from_json_string: nullable Object
+ fun deserialize_json(static_type: nullable String): nullable Object
do
var deserializer = new JsonDeserializer(self)
- var res = deserializer.deserialize
+ var res = deserializer.deserialize(static_type)
if deserializer.errors.not_empty then
print_error "Deserialization Errors: {deserializer.errors.join(", ")}"
end
open_array = arr
end
- # Try to get the name of the single parameter type assuming it is E.
- # This does not work in non-generic subclasses,
- # when the first parameter is not E, or
- # when there is more than one parameter. (The last one could be fixed)
- var class_name = class_name
- var items_type = null
- var bracket_index = class_name.index_of('[')
- if bracket_index != -1 then
- var start = bracket_index + 1
- var ending = class_name.last_index_of(']')
- items_type = class_name.substring(start, ending-start)
- end
+ # Name of the dynamic name of E
+ var items_type_name = (new GetName[E]).to_s
# Fill array
for o in open_array do
- var obj = v.convert_object(o, items_type)
+ var obj = v.convert_object(o, items_type_name)
if obj isa E then
add obj
- else v.errors.add new AttributeTypeError(self, "items", obj, "E")
+ else v.errors.add new AttributeTypeError(self, "items", obj, items_type_name)
end
end
end
v.notify_of_creation self
init
+ var keys_type_name = (new GetName[K]).to_s
+ var values_type_name = (new GetName[V]).to_s
+
var length = v.deserialize_attribute("__length")
var keys = v.path.last.get_or_null("__keys")
var values = v.path.last.get_or_null("__values")
+ if keys == null and values == null then
+ # Fallback to a plain object
+ for key, value_src in v.path.last do
+
+ var value = v.convert_object(value_src, values_type_name)
+
+ if not key isa K then
+ v.errors.add new AttributeTypeError(self, "keys", key, keys_type_name)
+ continue
+ end
+
+ if not value isa V then
+ v.errors.add new AttributeTypeError(self, "values", value, values_type_name)
+ continue
+ end
+
+ self[key] = value
+ end
+ return
+ end
+
# Length is optional
if length == null and keys isa SequenceRead[nullable Object] then length = keys.length
return
end
+ # First, convert all keys to follow the order of the serialization
+ var converted_keys = new Array[K]
for i in length.times do
- var key = v.convert_object(keys[i])
- var value = v.convert_object(values[i])
+ var key = v.convert_object(keys[i], keys_type_name)
if not key isa K then
- v.errors.add new AttributeTypeError(self, "keys", key, "K")
+ v.errors.add new AttributeTypeError(self, "keys", key, keys_type_name)
continue
end
+ converted_keys.add key
+ end
+
+ # Then convert the values and build the map
+ for i in length.times do
+ var key = converted_keys[i]
+ var value = v.convert_object(values[i], values_type_name)
+
if not value isa V then
- v.errors.add new AttributeTypeError(self, "values", value, "V")
+ v.errors.add new AttributeTypeError(self, "values", value, values_type_name)
continue
end
# Metamodel
# Class inheritance graph as a `POSet[String]` serialized to JSON
-private fun class_inheritance_metamodel_json: NativeString is intern
+private fun class_inheritance_metamodel_json: CString is intern
redef class Sys
- # Class inheritance graph
- #
- # ~~~
- # var hierarchy = class_inheritance_metamodel
- # assert hierarchy.has_edge("String", "Object")
- # assert not hierarchy.has_edge("Object", "String")
- # ~~~
- var class_inheritance_metamodel: POSet[String] is lazy do
+ redef var class_inheritance_metamodel is lazy do
var engine = new JsonDeserializer(class_inheritance_metamodel_json.to_s)
+ engine.check_subtypes = false
engine.whitelist.add_all(
- ["String", "POSet[String]", "POSetElement[String]", "HashSet[String]", "HashMap[String, POSetElement[String]]"])
+ ["String", "POSet[String]", "POSetElement[String]",
+ "HashSet[String]", "HashMap[String, POSetElement[String]]"])
+
var poset = engine.deserialize
if engine.errors.not_empty then
- print_error engine.errors.join("\n")
+ print_error "Deserialization errors in class_inheritance_metamodel:"
+ print_error engine.errors.join("\n* ")
return new POSet[String]
end
+
if poset isa POSet[String] then return poset
return new POSet[String]
end
end
-
-redef class Deserializer
- redef fun deserialize_class(name)
- do
- if name == "POSet[String]" then return new POSet[String].from_deserializer(self)
- if name == "POSetElement[String]" then return new POSetElement[String].from_deserializer(self)
- if name == "HashSet[String]" then return new HashSet[String].from_deserializer(self)
- if name == "HashMap[String, POSetElement[String]]" then return new HashMap[String, POSetElement[String]].from_deserializer(self)
-
- return super
- end
-end