Added json schema generation for models

cellardoor/__init__.py

@@ -2,6 +2,7 @@
 from version import __version__
 from .model import Model
 from .collection import Collection
+from .spec.jsonschema import to_jsonschema
 
 
 class CellarDoor(object):
@@ -36,4 +37,8 @@ def __init__(self, collections=(), authenticators=(), storage=None):
 						v = v.__name__
 					referenced_collection = self.collections_by_class_name.get(v)
 					new_links[k] = referenced_collection
-			collection.links = new_links
+			collection.links = new_links
+
+
+	def schema(self):
+		return to_jsonschema(self.model.entities)

cellardoor/spec/jsonschema.py

@@ -0,0 +1,124 @@
+from .. import model
+
+
+class JSONSchemaSerializer(object):
+
+	fallbacks = (
+		model.Text, model.Integer, model.Float, model.DateTime,
+		model.Boolean, model.Enum, model.ListOf, model.OneOf
+	)
+
+	def create_schema(self, entities):
+		return {
+			"$schema": "http://json-schema.org/draft-04/schema#",
+			"definitions": self.get_definitions(entities)
+		}
+
+
+	def get_definitions(self, entities):
+		definitions = {}
+		for e in entities:
+			definitions[e.__name__] = self.get_definition(e)
+		return definitions
+
+
+	def get_definition(self, entity):
+		props = {}
+		required_props = []
+		for k,v in entity.fields.items():
+			props[k] = self.get_property(v)
+			if v.required:
+				required_props.append(k)
+		definition =  {
+			'properties': props
+		}
+		if required_props:
+			definition['required'] = required_props
+		return definition
+
+
+	def get_property(self, field):
+		prop = {}
+		if field.help:
+			prop['description'] = field.help
+		type_name = field.__class__.__name__
+		method_name = 'handle_%s' % type_name
+		if not hasattr(self, method_name):
+			method_name = None
+			for cls in self.fallbacks:
+				if isinstance(field, cls):
+					method_name = 'handle_%s' % cls.__name__
+					break
+			if not method_name:
+				raise ValueError, "No handler for %s" % type_name
+		getattr(self, method_name)(field, prop)
+		return prop
+
+
+	def handle_Text(self, field, prop):
+		prop['type'] = 'string'
+		if field.maxlength:
+			prop['maxLength'] = field.maxlength
+		if field.minlength:
+			prop['maxLength'] = field.maxlength
+		if field.regex:
+			prop['pattern'] = field.regex.pattern
+
+
+	def handle_Integer(self, field, prop):
+		prop['type'] = 'integer'
+		if field.min:
+			prop['minimum'] = field.min
+		if field.max:
+			prop['maximum'] = field.max
+
+
+	def handle_Float(self, field, prop):
+		prop['type'] = 'number'
+
+
+	def handle_DateTime(self, field, prop):
+		self.handle_Text(field, prop)
+		prop['format'] = 'date-time'
+
+
+	def handle_Email(self, field, prop):
+		self.handle_Text(field, prop)
+		prop['format'] = 'email'
+
+
+	def handle_URL(self, field, prop):
+		self.handle_Text(field, prop)
+		prop['format'] = 'uri'
+
+
+	def handle_Boolean(self, field, prop):
+		prop['type'] = 'boolean'
+
+
+	def handle_Enum(self, field, prop):
+		prop['enum'] = field.values
+
+
+	def handle_ListOf(self, field, prop):
+		prop['type'] = 'array'
+		prop['items'] = self.get_property(field.field)
+
+
+	def handle_OneOf(self, field, prop):
+		prop['oneOf'] = map(self.get_property, field.fields)
+
+
+	def handle_Reference(self, field, prop):
+		self.handle_Text(field, prop)
+		prop['format'] = 'reference'
+		prop['schema'] = '#/definitions/%s' % field.entity.__name__
+
+
+
+def to_jsonschema(entities, cls=JSONSchemaSerializer):
+	serializer = cls()
+	return serializer.create_schema(entities)
+
+
+