endpoints -> webapp2 adapter

appengine/components/components/endpoints_webapp2.py

Index: appengine/components/components/endpoints_webapp2.py
diff --git a/appengine/components/components/endpoints_webapp2.py b/appengine/components/components/endpoints_webapp2.py
new file mode 100644
index 0000000000000000000000000000000000000000..a296b0fb065cdb977dac8a985766edc442c0c1e5
--- /dev/null
+++ b/appengine/components/components/endpoints_webapp2.py
@@ -0,0 +1,132 @@
+# Copyright 2016 The LUCI Authors. All rights reserved.
+# Use of this source code is governed under the Apache License, Version 2.0
+# that can be found in the LICENSE file.
+
+import endpoints
+import httplib
+import posixpath
+
+from endpoints import protojson
+from protorpc import message_types
+from protorpc import messages
+from protorpc import remote
+import webapp2
+
+
+PROTOCOL = protojson.EndpointsProtoJson()
+
+
+def decode_field(field, value):
+  """Like PROTOCOL.decode_field, but also supports booleans."""
+  if isinstance(field, messages.BooleanField):
+    value = value.lower()
+    if value == 'true':
+      return True
+    elif value == 'false':
+      return False
+    else:
+      raise ValueError('boolean field must be either "true" or "false"')
+  return PROTOCOL.decode_field(field, value)
+
+
+def decode_message(remote_method_info, request):
+  """Decodes a protorpc message from an webapp2 request.
+
+  If method accepts a resource container, parses field values from URL too.
+  """
+  req_msg = endpoints.ResourceContainer.get_request_message(remote_method_info)
+  if isinstance(req_msg, endpoints.ResourceContainer):
+    res_container = req_msg
+    body_type = req_msg.body_message_class
+  else:
+    res_container = None
+    body_type = remote_method_info.request_type
+
+  body = PROTOCOL.decode_message(body_type, request.body)
+  if not res_container:
+    return body
+
+  msg = res_container.combined_message_class()
+  for f in body.all_fields():
+    setattr(msg, f.name, getattr(body, f.name))
+
+  # We expect fields in the resource container to be in the URL.
+  for f in res_container.parameters_message_class.all_fields():
+    if f.name in request.route_kwargs:
+      values = [request.route_kwargs[f.name]]
+    else:
+      values = request.get_all(f.name)
+    if values:
+      values = [decode_field(f, v) for v in values]
+      if f.repeated:
+        getattr(msg, f.name).extend(values)
+      else:
+        setattr(msg, f.name, values[0])
+  return msg
+
+
+def path_handler(api_class, api_method, service_path):
+  """Returns a webapp2.RequestHandler subclass for the API methods."""
+  # Why return a class? Because webapp2 explicitly checks if handler that we
+  # passed to Route is a class.
+
+  class Handler(webapp2.RequestHandler):
+    def dispatch(self):
+      api = api_class()
+      api.initialize_request_state(remote.HttpRequestState(
+          remote_host=None,
+          remote_address=self.request.remote_addr,
+          server_host=self.request.host,
+          server_port=self.request.server_port,
+          http_method=self.request.method,
+          service_path=service_path,
+          headers=self.request.headers.items()))
+
+      try:
+        req = decode_message(api_method.remote, self.request)
+      except (messages.DecodeError, messages.ValidationError, ValueError) as ex:
+        self.response.write(ex.message)
+        self.response.write('\n')
+        self.response.set_status(httplib.BAD_REQUEST)
+        return
+
+      try:
+        res = api_method(api, req)
+      except endpoints.ServiceException as ex:
+        self.response.write(ex.message)
+        self.response.write('\n')
+        self.response.set_status(ex.http_status)
+        return
+
+      res_encoded = PROTOCOL.encode_message(res)
+      if isinstance(res, message_types.VoidMessage):
+        self.response.set_status(204)
+      self.response.content_type = 'application/json; charset=utf-8'
+      self.response.out.write(res_encoded)
+
+  return Handler
+
+
+def path_template_to_webapp2(template):
+  return template

[Vadim Sh., 2016/07/10 14:12:08]

huh?

[nodir, 2016/07/12 16:11:52]

https://codereview.chromium.org/2142093002/

+
+
+def api_routes(api_class, base_path=None):
+  base_path = base_path or '/api/%s/%s' % (
+      api_class.api_info.name,
+      api_class.api_info.version)
+  routes = []
+  for m in api_class.all_remote_methods().itervalues():
+    info = m.method_info
+
+    method_path = info.get_path(api_class.api_info)
+    method_path = method_path.replace('{', '<').replace('}', '>')
+    template = posixpath.join(base_path, method_path)
+
+    http_method = info.http_method.upper() or 'POST'
+
+    routes.append(webapp2.Route(
+        template,
+        path_handler(api_class, m, base_path),
+        methods=[http_method]))
+  return routes