A Facebook Graph API preprocessor to get albums for Grow

facebook_graph_yaml.py

"""
Convert Facebook Graph API responses to YAML.

To keep data secure. Use environment variable FACEBOOK_ACCESS_TOKEN
instead of storing in podspec
"""

import grow
from protorpc import messages
import requests
import json
import os
import yaml

class Error(Exception):
  pass

class InvalidHttpCodeError(Error):
  pass

class NoAccessTokenError(Error):
  pass

class BaseFbGraphYamlPreprocessor(grow.Preprocessor):
  _graph_url = 'https://graph.facebook.com'

  def run(self, build=True):
    if self.config.access_token is None:
      try:
        self.config.access_token = os.environ['FACEBOOK_ACCESS_TOKEN']
      except:
        raise NoAccessTokenError
    self.execute(self.config)

  def execute(self, config):
    raise NotImplementedError

class FbAlbumYamlPreprocessor(BaseFbGraphYamlPreprocessor):
  KIND = 'facebook_album_yaml'
  _album_url_format = BaseFbGraphYamlPreprocessor._graph_url + '/{version}/{id}/albums?access_token={access_token}&fields={fields}'

  class Config(messages.Message):
    id = messages.IntegerField(1)
    fields = messages.StringField(2)
    data_path = messages.StringField(3)
    gen_paths = messages.BooleanField(4, default=False)
    content_base = messages.StringField(5, default='/content/pages')
    album_path = messages.StringField(6, default='/{root}/{base}')
    view_path = messages.StringField(7, default='/views/photo-viewer.html')
    version = messages.StringField(8, default='v2.8')
    access_token = messages.StringField(9)

  @classmethod
  def get_album_url(cls, config):
    return  cls._album_url_format.format(id=config.id,
                                          version=config.version,
                                          access_token=config.access_token,
                                          fields=config.fields)

  @classmethod
  def download(cls, url):
    r = requests.get(url)
    data = r.json()
    return data['data']

  def _parse_path(self, path):
    if ':' in path:
      return path.rsplit(':', 1)
    return path, None

  def _create_document_for_album(self, config, album_data):
    content = {
        '$title': album_data['name'],
        '$path': config.album_path,
        'partials': [{
          'partial': config.view_path,
          'title': album_data['name'],
          'album_id': album_data['id'],
          'data_doc': '/data/albums.yaml'
        }]
    }
    album_name = '-'.join(album_data['name'].split(' '))
    content = json.dumps(content)
    content = yaml.safe_dump(yaml.safe_load(content), default_flow_style=False)
    self.logger.info('Album Name: {}'.format(album_name))
    file_path = '{}/{}.yaml'.format(config.content_base, album_name.lower())
    self.logger.info('Generating file at -> {}'.format(file_path))
    self.pod.write_file(file_path, content)

  def execute(self, config):
    data_path, key_to_update = self._parse_path(config.data_path)
    album_url = FbAlbumYamlPreprocessor.get_album_url(config)
    content = FbAlbumYamlPreprocessor.download(album_url)
    for album in content:
      self._create_document_for_album(config, album)
    content = json.dumps(content)
    content = yaml.safe_dump(yaml.safe_load(content),
                               default_flow_style=False)
    self.logger.info('Downloaded Album Data -> {}'.format(data_path))
    self.pod.write_file(data_path, content)