mediagoblin/tools/response.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 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 import werkzeug.utils
  18 from werkzeug.wrappers import Response as wz_Response
  19 from mediagoblin.tools.template import render_template
  20 from mediagoblin.tools.translate import (lazy_pass_to_ugettext as _,
  21                                          pass_to_ugettext)
  22
  23 class Response(wz_Response):
  24     """Set default response mimetype to HTML, otherwise we get text/plain"""
  25     default_mimetype = u'text/html'
  26
  27
  28 def render_to_response(request, template, context, status=200):
  29     """Much like Django's shortcut.render()"""
  30     return Response(
  31         render_template(request, template, context),
  32         status=status)
  33
  34
  35 def render_error(request, status=500, title=_('Oops!'),
  36                  err_msg=_('An error occured')):
  37     """Render any error page with a given error code, title and text body
  38
  39     Title and description are passed through as-is to allow html. Make
  40     sure no user input is contained therein for security reasons. The
  41     description will be wrapped in <p></p> tags.
  42     """
  43     return Response(render_template(request, 'mediagoblin/error.html',
  44         {'err_code': status, 'title': title, 'err_msg': err_msg}),
  45         status=status)
  46
  47
  48 def render_403(request):
  49     """Render a standard 403 page"""
  50     _ = pass_to_ugettext
  51     title = _('Operation not allowed')
  52     err_msg = _("Sorry Dave, I can't let you do that!</p><p>You have tried "
  53                 " to perform a function that you are not allowed to. Have you "
  54                 "been trying to delete all user accounts again?")
  55     return render_error(request, 403, title, err_msg)
  56
  57 def render_404(request):
  58     """Render a standard 404 page."""
  59     _ = pass_to_ugettext
  60     err_msg = _("There doesn't seem to be a page at this address. Sorry!</p>"
  61                 "<p>If you're sure the address is correct, maybe the page "
  62                 "you're looking for has been moved or deleted.")
  63     return render_error(request, 404, err_msg=err_msg)
  64
  65
  66 def render_http_exception(request, exc, description):
  67     """Return Response() given a werkzeug.HTTPException
  68
  69     :param exc: werkzeug.HTTPException or subclass thereof
  70     :description: message describing the error."""
  71     # If we were passed the HTTPException stock description on
  72     # exceptions where we have localized ones, use those:
  73     stock_desc = (description == exc.__class__.description)
  74
  75     if stock_desc and exc.code == 403:
  76         return render_403(request)
  77     elif stock_desc and exc.code == 404:
  78         return render_404(request)
  79
  80     return render_error(request, title=exc.args[0],
  81                         err_msg=description,
  82                         status=exc.code)
  83
  84
  85 def redirect(request, *args, **kwargs):
  86     """Redirects to an URL, using urlgen params or location string
  87
  88     :param querystring: querystring to be appended to the URL
  89     :param location: If the location keyword is given, redirect to the URL
  90     """
  91     querystring = kwargs.pop('querystring', None)
  92
  93     # Redirect to URL if given by "location=..."
  94     if 'location' in kwargs:
  95         location = kwargs.pop('location')
  96     else:
  97         location = request.urlgen(*args, **kwargs)
  98
  99     if querystring:
 100         location += querystring
 101     return werkzeug.utils.redirect(location)
 102
 103
 104 def redirect_obj(request, obj):
 105     """Redirect to the page for the given object.
 106
 107     Requires obj to have a .url_for_self method."""
 108     return redirect(request, location=obj.url_for_self(request.urlgen))