Merge pull request #37 from LiUGraphQL/query-by-key

Support for keys in API schema generation (Issue #33)

Author: hartig

graphql-api-generator/generator.py

@@ -96,6 +96,10 @@ def run(schema: GraphQLSchema, config: dict):
             schema = add_list_of_types(schema)
             schema = add_list_queries(schema)
 
+        if config.get('generation').get('query_by_key'):
+            schema = add_key_input_types(schema)
+            schema = add_key_queries(schema)
+
         # add input types
         if config.get('generation').get('input_to_create_objects'):
             schema = add_input_to_create(schema)

graphql-api-generator/resources/config.yml

@@ -21,6 +21,7 @@ generation:
     query_by_id: true
     query_type_filter: true
     query_list_of: true
+    query_by_key: true
     # add input types
     input_to_create_objects: true
     input_to_update_objects: true

graphql-api-generator/utils/utils.py

@@ -194,6 +194,71 @@ def add_input_to_create(schema: GraphQLSchema):
     return schema
 
 
+def _get_keys_for_type(type_: GraphQLType):
+    keys = []
+    if hasattr(type_, 'ast_node') and type_.ast_node is not None:
+        directives = {directive.name.value: directive for directive in type_.ast_node.directives}
+        if 'key' in directives:
+            arguments = {arg.name.value: arg for arg in directives['key'].arguments}
+            if 'fields' in arguments:
+                keys.append([val.value for val in arguments['fields'].value.values])
+    return keys
+
+
+def add_key_input_types(schema: GraphQLSchema):
+    """
+    Add create and connect types for creating objects.
+    :param schema:
+    :return:
+    """
+    # add create types (placeholders)
+    make_types = ''
+    extend_fields = ''
+    for _type in schema.type_map.values():
+        if not is_schema_defined_type(_type) or is_interface_type(_type):
+            continue
+        keys = _get_keys_for_type(_type)
+        # TODO: Modify this when we need to handle multiple keys.
+        if len(keys) > 0:
+            for key in keys[:1]:
+                make_types += f'input _KeyFor{_type.name} '
+                extend_fields += f'\nextend input _KeyFor{_type.name} {{ '
+                for key_field in key:
+                    if key_field not in _type.fields:
+                        raise Exception(f'Field "{key_field}" in @key directive for {_type} is not a field of {_type}!')
+                for field_name, field in _type.fields.items():
+                    # TODO: Modify this if we need to verify that the key fields are in the object
+                    if field_name not in key:
+                        continue
+                    extend_fields += f'{field_name}: {field.type} '
+                extend_fields += '} '
+    schema = add_to_schema(schema, make_types)
+    schema = add_to_schema(schema, extend_fields)
+    return schema
+
+
+def add_key_queries(schema: GraphQLSchema):
+    """
+    Add query to get object based on ID.
+    :param schema:
+    :return:
+    """
+    # Create queries for object types
+    make = ''
+    for _type in schema.type_map.values():
+        if not is_schema_defined_type(_type):
+            continue
+        keys = _get_keys_for_type(_type)
+        # TODO: Handle multiple keys here, somehow.
+        if len(keys) > 0:
+            # for key in keys[:1]:
+            query_name = f'{decapitalize(_type.name)}ByKey'
+            key_type = f'_KeyFor{_type.name}'
+            make += f'extend type Query {{ {query_name}(key:{key_type}!): {_type.name} }} '
+    schema = add_to_schema(schema, make)
+    return schema
+
+
 def extend_connect(schema: GraphQLSchema, _type: GraphQLType, field_type: GraphQLType, field_name: str):
     """
     Add connect type.