standarize ajaxable dialogs

[wolnelektury.git] / apps / ajaxable / utils.py

diff --git a/apps/ajaxable/utils.py b/apps/ajaxable/utils.py
new file mode 100755 (executable)
index 0000000..14b5dfc
--- /dev/null
+++ b/apps/ajaxable/utils.py
@@ -0,0 +1,82 @@
+from django.http import HttpResponse, HttpResponseRedirect
+from django.shortcuts import render_to_response
+from django.template import RequestContext
+from django.utils.encoding import force_unicode
+from django.utils.functional import Promise
+from django.utils.http import urlquote_plus
+from django.utils import simplejson
+from django.utils.translation import ugettext_lazy as _
+
+
+class LazyEncoder(simplejson.JSONEncoder):
+    def default(self, obj):
+        if isinstance(obj, Promise):
+            return force_unicode(obj)
+        return obj
+
+# shortcut for JSON reponses
+class JSONResponse(HttpResponse):
+    def __init__(self, data={}, callback=None, **kwargs):
+        # get rid of mimetype
+        kwargs.pop('mimetype', None)
+        data = simplejson.dumps(data)
+        if callback:
+            data = callback + "(" + data + ");" 
+        super(JSONResponse, self).__init__(data, mimetype="application/json", **kwargs)
+
+
+
+class AjaxableFormView(object):
+    """Subclass this to create an ajaxable view for any form.
+
+    In the subclass, provide at least form_class.
+
+    """
+    form_class = None
+    # override to customize form look
+    template = "ajaxable/form.html"
+    # set to redirect after succesful ajax-less post
+    submit = _('Send')
+    redirect = None
+    title = ''
+    success_message = ''
+    formname = "form"
+    full_template = "ajaxable/form_on_page.html"
+
+    def __call__(self, request):
+        """A view displaying a form, or JSON if `ajax' GET param is set."""
+        ajax = request.GET.get('ajax', False)
+        if request.method == "POST":
+            form = self.form_class(data=request.POST)
+            if form.is_valid():
+                self.success(form, request)
+                redirect = request.GET.get('next')
+                if not ajax and redirect is not None:
+                    return HttpResponseRedirect(urlquote_plus(
+                                redirect, safe='/?='))
+                response_data = {'success': True, 'message': self.success_message}
+            else:
+                response_data = {'success': False, 'errors': form.errors}
+            if ajax:
+                return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
+        else:
+            form = self.form_class()
+            response_data = None
+
+        template = self.template if ajax else self.full_template
+        return render_to_response(template, {
+                self.formname: form, 
+                "title": self.title,
+                "submit": self.submit,
+                "response_data": response_data,
+                "ajax_template": self.template,
+            },
+            context_instance=RequestContext(request))
+
+    def success(self, form, request):
+        """What to do when the form is valid.
+        
+        By default, just save the form.
+
+        """
+        return form.save(request)