Source code for marshmallow_utils.fields.links
# -*- coding: utf-8 -*-
#
# Copyright (C) 2020 CERN.
#
# Marshmallow-Utils is free software; you can redistribute it and/or modify
# it under the terms of the MIT License; see LICENSE file for more details.
"""Link store and field for generating links."""
from marshmallow import fields, missing
from uritemplate import URITemplate
[docs]class Links(fields.Field):
"""A links field that knows to look in the context for the schema."""
# NOTE: forces serialization
_CHECK_ATTRIBUTE = False
def _serialize(self, value, attr, obj, *args, **kwargs):
"""Dump the field by using the contextual schema."""
factory = self.context.get("links_factory")
namespace = self.context.get("links_namespace")
schema = factory.get_schema(namespace, self.context) if factory else None
if schema:
return schema.dump(obj)
else:
return {}
def always(*args, **kwargs):
"""A function that returns True no matter what is passed to it."""
return True
[docs]class Link(fields.Field):
"""A link field that knows how to generate a link from an object."""
# NOTE: forces serialization
_CHECK_ATTRIBUTE = False
def __init__(
self, template=None, params=None, permission=None, when=always, **kwargs
):
"""Constructor."""
if isinstance(template, str):
template = URITemplate(template)
self.template = template
self.permission = permission
self.params = params
self.when = when
super().__init__(**kwargs)
def _serialize(self, value, attr, obj, *args, **kwargs):
"""Dump the link by using the context."""
factory = self.context.get("links_factory")
field_permission_check = self.context.get("field_permission_check")
if field_permission_check and self.permission:
if not field_permission_check(self.permission):
return missing
if not self.when(obj):
return missing
return factory.create_link(self.template, self.params(obj))
