apps/ajaxable/utils.py

   1 from functools import wraps
   2
   3 from django.http import (HttpResponse, HttpResponseRedirect,
   4         HttpResponseForbidden)
   5 from django.shortcuts import render_to_response
   6 from django.template import RequestContext
   7 from django.utils.encoding import force_unicode
   8 from django.utils.functional import Promise
   9 from django.utils.http import urlquote_plus
  10 from django.utils import simplejson
  11 from django.utils.translation import ugettext_lazy as _
  12 from django.views.decorators.vary import vary_on_headers
  13 from honeypot.decorators import verify_honeypot_value
  14
  15
  16 class LazyEncoder(simplejson.JSONEncoder):
  17     def default(self, obj):
  18         if isinstance(obj, Promise):
  19             return force_unicode(obj)
  20         return obj
  21
  22 # shortcut for JSON reponses
  23 class JSONResponse(HttpResponse):
  24     def __init__(self, data={}, callback=None, **kwargs):
  25         # get rid of mimetype
  26         kwargs.pop('mimetype', None)
  27         data = simplejson.dumps(data)
  28         if callback:
  29             data = callback + "(" + data + ");"
  30         super(JSONResponse, self).__init__(data, mimetype="application/json", **kwargs)
  31
  32
  33 def method_decorator(function_decorator):
  34     """Converts a function decorator to a method decorator.
  35
  36     It just makes it ignore first argument.
  37     """
  38     def decorator(method):
  39         @wraps(method)
  40         def wrapped_method(self, *args, **kwargs):
  41             def function(*fargs, **fkwargs):
  42                 return method(self, *fargs, **fkwargs)
  43             return function_decorator(function)(*args, **kwargs)
  44         return wrapped_method
  45     return decorator
  46
  47
  48 def require_login(request):
  49     """Return 403 if request is AJAX. Redirect to login page if not."""
  50     if request.is_ajax():
  51         return HttpResponseForbidden('Not logged in')
  52     else:
  53         return HttpResponseRedirect('/uzytkownicy/zaloguj')# next?=request.build_full_path())
  54
  55
  56 def placeholdized(form):
  57     for field in form.fields.values():
  58         field.widget.attrs['placeholder'] = field.label
  59     return form
  60
  61
  62 class AjaxableFormView(object):
  63     """Subclass this to create an ajaxable view for any form.
  64
  65     In the subclass, provide at least form_class.
  66
  67     """
  68     form_class = None
  69     placeholdize = False
  70     # override to customize form look
  71     template = "ajaxable/form.html"
  72     submit = _('Send')
  73
  74     title = ''
  75     success_message = ''
  76     POST_login = False
  77     formname = "form"
  78     form_prefix = None
  79     full_template = "ajaxable/form_on_page.html"
  80     honeypot = False
  81
  82     @method_decorator(vary_on_headers('X-Requested-With'))
  83     def __call__(self, request, *args, **kwargs):
  84         """A view displaying a form, or JSON if request is AJAX."""
  85         obj = self.get_object(request, *args, **kwargs)
  86         form_args, form_kwargs = self.form_args(request, obj)
  87         if self.form_prefix:
  88             form_kwargs['prefix'] = self.form_prefix
  89
  90         if request.method == "POST":
  91             if self.honeypot:
  92                 response = verify_honeypot_value(request, None)
  93                 if response:
  94                     return response
  95
  96             # do I need to be logged in?
  97             if self.POST_login and not request.user.is_authenticated():
  98                 return require_login(request)
  99
 100             form_kwargs['data'] = request.POST
 101             form = self.form_class(*form_args, **form_kwargs)
 102             if form.is_valid():
 103                 add_args = self.success(form, request)
 104                 redirect = request.GET.get('next')
 105                 if not request.is_ajax() and redirect:
 106                     return HttpResponseRedirect(urlquote_plus(
 107                             redirect, safe='/?=&'))
 108                 response_data = {'success': True,
 109                     'message': self.success_message, 'redirect': redirect}
 110                 if add_args:
 111                     response_data.update(add_args)
 112             elif request.is_ajax():
 113                 # Form was sent with errors. Send them back.
 114                 if self.form_prefix:
 115                     errors = {}
 116                     for key, value in form.errors.items():
 117                         errors["%s-%s" % (self.form_prefix, key)] = value
 118                 else:
 119                     errors = form.errors
 120                 response_data = {'success': False, 'errors': errors}
 121             else:
 122                 response_data = None
 123             if request.is_ajax():
 124                 return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
 125         else:
 126             if (self.POST_login and not request.user.is_authenticated()
 127                     and not request.is_ajax()):
 128                 return require_login(request)
 129
 130             form = self.form_class(*form_args, **form_kwargs)
 131             response_data = None
 132
 133         title = self.title
 134         if request.is_ajax():
 135             template = self.template
 136         else:
 137             template = self.full_template
 138             cd = self.context_description(request, obj)
 139             if cd:
 140                 title += ": " + cd
 141         if self.placeholdize:
 142             form = placeholdized(form)
 143         context = {
 144                 self.formname: form,
 145                 "title": title,
 146                 "honeypot": self.honeypot,
 147                 "placeholdize": self.placeholdize,
 148                 "submit": self.submit,
 149                 "response_data": response_data,
 150                 "ajax_template": self.template,
 151                 "view_args": args,
 152                 "view_kwargs": kwargs,
 153             }
 154         context.update(self.extra_context(request, obj))
 155         return render_to_response(template, context,
 156             context_instance=RequestContext(request))
 157
 158     def redirect_or_refresh(self, request, path, message=None):
 159         """If the form is AJAX, refresh the page. If not, go to `path`."""
 160         if request.is_ajax():
 161             output = "<script>window.location.reload()</script>"
 162             if message:
 163                 output = "<div class='normal-text'>" + message + "</div>" + output
 164             return HttpResponse(output);
 165         else:
 166             return HttpResponseRedirect(path)
 167
 168     def get_object(self, request, *args, **kwargs):
 169         """Override to parse view args and get some associated data."""
 170         return None
 171
 172     def form_args(self, request, obj):
 173         """Override to parse view args and give additional args to the form."""
 174         return (), {}
 175
 176     def extra_context(self, request, obj):
 177         """Override to pass something to template."""
 178         return {}
 179
 180     def context_description(self, request, obj):
 181         """Description to appear in standalone form, but not in AJAX form."""
 182         return ""
 183
 184     def success(self, form, request):
 185         """What to do when the form is valid.
 186
 187         By default, just save the form.
 188
 189         """
 190         return form.save(request)