Add task_list demo.

demo/README.md

@@ -1,7 +1,15 @@
-# ndb demo application
+# ndb demo applications
 
 ## Overview
 
+There are three separate demos:
+
+* app: a Google App Engine application with a set of example uses
+* shell: an application that sets up the ndb environment then opens up a python shell for you to interact with.
+* task_list: a basic application which runs inside Compute Engine.
+
+## app (App Engine Application)
+
 This demo shows various ways to use ndb. The application consists of serveral
 different handlers.
 * hello.py: a simple hello world application.
@@ -13,7 +21,7 @@ different handlers.
 
 This folder also has a demo for using ndb from outside of App Engine. You can use `shell.py` to interact with your Datastore using ndb through the Cloud Datastore API.
 
-## Setup (demo application)
+### Setup
 
 1. Copy ndb (the entire folder) into the demo subdirectory.
 2. Deploy the demo application using the command:
@@ -24,18 +32,44 @@ This folder also has a demo for using ndb from outside of App Engine. You can us
 
            gcloud config set project <project-id>
 
-## Shell
+## shell
+
+1. Follow the instructions below to setup ndb in GCE.
+
+2. Run the shell. From here you can write ndb code to interact with Datastore. Don't forget, this shell is interacting with the production Datastore of your <project-id>.
+
+           python demo/shell.py
+
+## Task List
+
+1. Follow the instructions below to setup ndb in GCE.
+
+2. Run the task list application. Don't forget, this application is interacting with the production Datastore of your <project-id>.
+
+           python demo/task_list.py
 
-1. First, ensure your environment is setup.
+# Setup from your local machine or from Google Compute Engine
+
+1. Install pip
+
+           sudo apt-get update
+           sudo apt-get install python-pip
+
+2. Install the Google App Engine SDK and point ndb to the installation. If you installed `gcloud` to a different location then your App Engine SDK may be installed in a different location. 
+
+           sudo gcloud components install app-engine-python
+           export GAE=/usr/local/share/google/google-cloud-sdk/platform/google_appengine
+
+3. Install ndb
+
+           pip install --pre ndb
+
+4. Setup your environment.
 
            export DATASTORE_PROJECT_ID=<project-id>
            export DATASTORE_USE_PROJECT_ID_AS_APP_ID=true
 
-2. Then, make sure you have authenticated using gcloud.
+5. Finally, make sure you have authenticated using gcloud.
 
            gcloud auth login
 
-3. Finally, run the shell. From here you can write ndb code to interact with Datastore. Don't forget, this shell is interacting with the production Datastore of your <project-id>.
-
-           python demo/shell.py
-

demo/app/__init__.py

@@ -0,0 +1,17 @@
+#
+# Copyright 2016 The ndb Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# This file intentionally left blank.

demo/task_list.py

@@ -0,0 +1,183 @@
+#!/usr/bin/python
+
+# Copyright 2015 Google Inc. All Rights Reserved.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# [START all]
+"""Sample for Cloud Datastore using the NDB client library.
+
+This is a command-line task list manager.
+
+From the command line, first setup the necessary environment variables.
+export DATASTORE_PROJECT_ID=<my-project-id>
+export DATASTORE_USE_PROJECT_ID_AS_APP_ID=true
+"""
+
+import ndb
+# [START build_service]
+# When running outside of App Engine, ndb caching policies should be adjusted.
+# The local cache is never evicted, so it should be turned off for any long
+# running processes. In order to use memcache, App Engine Remote API must be
+# installed. Note that if you are running ndb both inside and outside of
+# App Engine, your memcache policies *must* match. Otherwise, calling put may
+# not invalidate your cache and App Engine ndb will get stale results.
+ndb.get_context().set_cache_policy(False)
+ndb.get_context().set_memcache_policy(False)
+# [END build_service]
+
+
+# [START add_entity]
+# Define the model we will be using for the tasks.
+class Task(ndb.Model):
+  description = ndb.StringProperty()
+  created = ndb.DateTimeProperty(auto_now_add=True)
+  done = ndb.BooleanProperty(default=False)
+
+
+def add_task(description):
+  """Adds a new task to the Datastore.
+
+  Args:
+    description: A string description of the task.
+
+  Returns:
+    The key of the entity that was put.
+  """
+  return Task(description=description).put()
+# [END add_entity]
+
+
+# [START update_entity]
+@ndb.transactional
+def mark_done(task_id):
+  """Marks a task as done.
+
+  Args:
+    task_id: The integer id of the task to update.
+
+  Raises:
+    ValueError: if the requested task doesn't exist.
+  """
+  task = Task.get_by_id(task_id)
+  if task is None:
+    raise ValueError('Task with id %d does not exist' % task_id)
+  task.done = True
+  task.put()
+# [END update_entity]
+
+
+# [START retrieve_entities]
+def list_tasks():
+  """Lists all the task entities in ascending order of completion time.
+
+  Returns:
+    A list of tasks.
+  """
+  # Querying the tasks without an ancestor is eventually consistent.
+  return list(Task.query().order(Task.created))
+# [END retrieve_entities]
+
+
+# [START delete_entity]
+def delete_task(task_id):
+  """Deletes the given task.
+
+  Args:
+    task_id: The integer id of the task to delete.
+  """
+  ndb.Key('Task', task_id).delete()
+# [END delete_entity]
+
+
+# [START format_results]
+def format_tasks(tasks):
+  """Converts a list of tasks to a list of string representations.
+
+  Args:
+    tasks: A list of the tasks to convert.
+  Returns:
+    A list of string formatted tasks.
+  """
+  return ['%d : %s (%s)' % (task.key.id(),
+                            task.description,
+                            ('done' if task.done
+                             else 'created %s' % task.created))
+          for task in tasks]
+# [END format_results]
+
+
+def get_arg(cmds):
+  """Accepts a split string command and validates its size.
+
+  Args:
+    cmds: A split command line as a list of strings.
+
+  Returns:
+    The string argument to the command.
+
+  Raises:
+    ValueError: If there is no argument.
+  """
+  if len(cmds) != 2:
+    raise ValueError('%s needs an argument.' % cmds[0])
+  return cmds[1]
+
+
+def handle_command(command):
+  """Accepts a string command and performs an action.
+
+  Args:
+    command: the command to run as a string.
+  """
+  try:
+    cmds = command.split(None, 1)
+    cmd = cmds[0]
+    if cmd == 'new':
+      add_task(get_arg(cmds))
+    elif cmd == 'done':
+      mark_done(int(get_arg(cmds)))
+    elif cmd == 'list':
+      for task in format_tasks(list_tasks()):
+        print task
+    elif cmd == 'delete':
+      delete_task(int(get_arg(cmds)))
+    else:
+      print_usage()
+  except Exception, e:  # pylint: disable=broad-except
+    print e
+    print_usage()
+
+
+def print_usage():
+  """Print the usage of our task list command."""
+  print 'Usage:'
+  print ''
+  print '  new <description>  Adds a task with a description <description>'
+  print '  done <task-id>     Marks a task as done'
+  print '  list               Lists all tasks by creation time'
+  print '  delete <task-id>   Deletes a task'
+  print ''
+
+
+def main():
+  print 'Cloud Datastore Task List'
+  print ''
+  print_usage()
+  while True:
+    line = raw_input('> ')
+    if not line:
+      break
+    handle_command(line)
+
+if __name__ == '__main__':
+  main()
+# [END all]