mediagoblin/plugins/piwigo/tools.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2013 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 from collections import namedtuple
  18 import logging
  19
  20 import six
  21 import lxml.etree as ET
  22 from werkzeug.exceptions import MethodNotAllowed, BadRequest
  23
  24 from mediagoblin.tools.request import setup_user_in_request
  25 from mediagoblin.tools.response import Response
  26
  27
  28 _log = logging.getLogger(__name__)
  29
  30
  31 PwgError = namedtuple("PwgError", ["code", "msg"])
  32
  33
  34 class PwgNamedArray(list):
  35     def __init__(self, l, item_name, as_attrib=()):
  36         self.item_name = item_name
  37         self.as_attrib = as_attrib
  38         list.__init__(self, l)
  39
  40     def fill_element_xml(self, el):
  41         for it in self:
  42             n = ET.SubElement(el, self.item_name)
  43             if isinstance(it, dict):
  44                 _fill_element_dict(n, it, self.as_attrib)
  45             else:
  46                 _fill_element(n, it)
  47
  48
  49 def _fill_element_dict(el, data, as_attr=()):
  50     for k, v in six.iteritems(data):
  51         if k in as_attr:
  52             if not isinstance(v, six.string_types):
  53                 v = str(v)
  54             el.set(k, v)
  55         else:
  56             n = ET.SubElement(el, k)
  57             _fill_element(n, v)
  58
  59
  60 def _fill_element(el, data):
  61     if isinstance(data, bool):
  62         if data:
  63             el.text = "1"
  64         else:
  65             el.text = "0"
  66     elif isinstance(data, six.string_types):
  67         el.text = data
  68     elif isinstance(data, int):
  69         el.text = str(data)
  70     elif isinstance(data, dict):
  71         _fill_element_dict(el, data)
  72     elif isinstance(data, PwgNamedArray):
  73         data.fill_element_xml(el)
  74     else:
  75         _log.warn("Can't convert to xml: %r", data)
  76
  77
  78 def response_xml(result):
  79     r = ET.Element("rsp")
  80     r.set("stat", "ok")
  81     status = None
  82     if isinstance(result, PwgError):
  83         r.set("stat", "fail")
  84         err = ET.SubElement(r, "err")
  85         err.set("code", str(result.code))
  86         err.set("msg", result.msg)
  87         if result.code >= 100 and result.code < 600:
  88             status = result.code
  89     else:
  90         _fill_element(r, result)
  91     return Response(ET.tostring(r, encoding="utf-8", xml_declaration=True),
  92                     mimetype='text/xml', status=status)
  93
  94
  95 class CmdTable(object):
  96     _cmd_table = {}
  97
  98     def __init__(self, cmd_name, only_post=False):
  99         assert not cmd_name in self._cmd_table
 100         self.cmd_name = cmd_name
 101         self.only_post = only_post
 102
 103     def __call__(self, to_be_wrapped):
 104         assert not self.cmd_name in self._cmd_table
 105         self._cmd_table[self.cmd_name] = (to_be_wrapped, self.only_post)
 106         return to_be_wrapped
 107
 108     @classmethod
 109     def find_func(cls, request):
 110         if request.method == "GET":
 111             cmd_name = request.args.get("method")
 112         else:
 113             cmd_name = request.form.get("method")
 114         entry = cls._cmd_table.get(cmd_name)
 115         if not entry:
 116             return entry
 117         _log.debug("Found method %s", cmd_name)
 118         func, only_post = entry
 119         if only_post and request.method != "POST":
 120             _log.warn("Method %s only allowed for POST", cmd_name)
 121             raise MethodNotAllowed()
 122         return func
 123
 124
 125 def check_form(form):
 126     if not form.validate():
 127         _log.error("form validation failed for form %r", form)
 128         for f in form:
 129             if len(f.errors):
 130                 _log.error("Errors for %s: %r", f.name, f.errors)
 131         raise BadRequest()
 132     dump = []
 133     for f in form:
 134         dump.append("%s=%r" % (f.name, f.data))
 135     _log.debug("form: %s", " ".join(dump))
 136
 137
 138 class PWGSession(object):
 139     session_manager = None
 140
 141     def __init__(self, request):
 142         self.request = request
 143         self.in_pwg_session = False
 144
 145     def __enter__(self):
 146         # Backup old state
 147         self.old_session = self.request.session
 148         self.old_user = self.request.user
 149         # Load piwigo session into state
 150         self.request.session = self.session_manager.load_session_from_cookie(
 151             self.request)
 152         setup_user_in_request(self.request)
 153         self.in_pwg_session = True
 154         return self
 155
 156     def __exit__(self, *args):
 157         # Restore state
 158         self.request.session = self.old_session
 159         self.request.user = self.old_user
 160         self.in_pwg_session = False
 161
 162     def save_to_cookie(self, response):
 163         assert self.in_pwg_session
 164         self.session_manager.save_session_to_cookie(self.request.session,
 165             self.request, response)