Simple way to display IMAP errors:

* raise a specific exception in the imap connector,
 * Add a simple middleware to catch this exception and return a specific response that will be correctly displayed by the webmail.

see #127

extensions/webmail/lib.py

@@ -18,6 +18,19 @@ from modoboa.lib import decode, tables, imap_utf7, Singleton
 from modoboa.lib.email_listing import MBconnector, EmailListing, Email
 from modoboa.lib import tables, imap_utf7, parameters, static_url, u2u_decode
 
+class WebmailError(Exception):
+    errorexpr = re.compile("\[([^\]]+)\]\s*([^\.]+)")
+
+    def __init__(self, reason, ajax=False):
+        m = WebmailError.errorexpr.match(reason)
+        if m is None:
+            self.reason = reason
+        else:
+            self.reason = "%s: %s" % (_("Server response"), m.group(2))
+        self.ajax = ajax
+
+    def __str__(self):
+        return self.reason
 
 class WMtable(tables.Table):
     tableid = "emails"
@@ -315,20 +328,20 @@ class IMAPconnector(object):
             name = "%s.%s" % (parent, name)
         typ, data = self.m.create(self._encodefolder(name))
         if typ == "NO":
-            return False
+            raise WebmailError(data[0])
         return True
 
     def rename_folder(self, oldname, newname):
         typ, data = self.m.rename(self._encodefolder(oldname),
                                   self._encodefolder(newname))
         if typ == "NO":
-            return False
+            raise WebmailError(data[0], ajax=True)
         return True
 
     def delete_folder(self, name):
         typ, data = self.m.delete(self._encodefolder(name))
         if typ == "NO":
-            return False
+            raise WebmailError(data[0])
         return True
 
     def getquota(self, folder):

extensions/webmail/middleware.py

@@ -0,0 +1,11 @@
+# coding: utf-8
+
+from modoboa.lib import ajax_response
+from modoboa.extensions.webmail.lib import WebmailError
+
+class WebmailErrorMiddleware(object):
+    def process_exception(self, request, exception):
+        if not isinstance(exception, WebmailError):
+            return None
+        return ajax_response(request, status="ko", 
+                             error=str(exception), norefresh=True)

extensions/webmail/static/js/webmail.js

@@ -59,14 +59,8 @@ function viewmail_cb(resp) {
   $$("a[name=forward]").addEvent("click", forward_loader);
   $$("a[name=delete]").addEvent("click", function(event) {
     var lnk = event.target;
-
     event.stop();
-    new Request.JSON({
-      url: lnk.get("href"), onSuccess: function(resp) {
-        current_anchor.parse_string(resp.next).update();
-        select_folder($$("a[href=" + current_anchor.getbaseurl() + "]"));
-      }
-    }).get();
+    simple_request(lnk.get("href"));
   });
   $$("a[name=activate_links]").addEvent("click", function(evt) {
     evt.stop();
@@ -219,9 +213,22 @@ function simple_request(url, params) {
   new Request.JSON({
     url : url,
     onSuccess : function(response) {
-      get_callback("folder")(response);
-      infobox.info(gettext("Done"));
-      infobox.hide(1);
+      if (response.status == "ok") {
+        if (!$defined(response.next)) {
+          get_callback("folder")(response);
+        }
+        infobox.info(gettext("Done"));
+        if ($defined(response.next)) {
+          (function(response) {
+            current_anchor.parse_string(response.next).update();
+            select_folder($$("a[href=" + current_anchor.getbaseurl() + "]"));
+          }).delay(500, this, response);
+        } else {
+          infobox.hide(1);
+        }
+      } else {
+        infobox.error(response.error);
+      }
     }
   }).get(params);
 }

extensions/webmail/templates/webmail/folder.html

@@ -29,6 +29,7 @@
 {% endblock %}
 {% block content %}
 <div class="title"><h1>{{ title }}</h1></div>
+<div id="error" class="error">{{ error }}</div>
 <form action="" method="POST" id="{{ fname }}" name="{{ fname }}">
   <input type="hidden" name="oldname" value="{{ oldname }}" />
   {% include "common/genericform.html" %}

extensions/webmail/views.py

@@ -105,7 +105,8 @@ def folder(request, name, updatenav=True):
         optparams["criteria"] = request.session["criteria"]
     else:
         optparams["reset"] = True
-        optparams["elems_per_page"] = int(parameters.get_user(request.user, "MESSAGES_PER_PAGE"))
+        optparams["elems_per_page"] = \
+            int(parameters.get_user(request.user, "MESSAGES_PER_PAGE"))
     lst = ImapListing(request.user, request.session["password"],
                       baseurl=name, folder=name, order=order, 
                       **optparams)
@@ -457,9 +458,9 @@ def newfolder(request, tplname="webmail/folder.html"):
         if form.is_valid():
             pf = request.POST.has_key("parent_folder") \
                 and request.POST["parent_folder"] or None
-            if mbc.create_folder(form.cleaned_data["name"], pf):
-                return ajax_response(request, ajaxnav=True)
-
+            mbc.create_folder(form.cleaned_data["name"], pf)
+            return ajax_response(request, ajaxnav=True)
+            
         ctx["form"] = form
         ctx["selected"] = None
         return ajax_response(request, status="ko", template=tplname, **ctx)
@@ -492,8 +493,7 @@ def editfolder(request, tplname="webmail/folder.html"):
                         or (pf is not None and pf != oldparent):
                     newname = form.cleaned_data["name"] if pf is None \
                         else "%s.%s" % (pf, form.cleaned_data["name"])
-                    if not mbc.rename_folder(request.POST["oldname"], newname):
-                        raise Exception
+                    mbc.rename_folder(request.POST["oldname"], newname)
                     extra["url"] = newname
                 return ajax_response(request, ajaxnav=True, **extra)
             except Exception:
@@ -518,6 +518,5 @@ def delfolder(request):
         return
     mbc = IMAPconnector(user=request.user.username, 
                         password=request.session["password"])
-    if mbc.delete_folder(request.GET["name"]):
-        return ajax_response(request)
+    mbc.delete_folder(request.GET["name"])
     return ajax_response(request, status="ko")

lib/__init__.py

@@ -74,7 +74,9 @@ def getctx(status, level=1, callback=None, **kwargs):
         ctx[kw] = v
     return ctx
 
-def ajax_response(request, status="ok", url="", ajaxnav=False, template=None, **kwargs):
+def ajax_response(request, status="ok", error=None,
+                  url="", ajaxnav=False, norefresh=False, 
+                  template=None, **kwargs):
     """Ajax response shortcut
 
     Simple shortcut that sends an JSON response. If a template is
@@ -95,10 +97,13 @@ def ajax_response(request, status="ok", url="", ajaxnav=False, template=None, **
     else:
         content = ""
     jsonctx = {"status" : status, "content" : content}
+    if error is not None:
+        jsonctx["error"] = error
     if ajaxnav:
         jsonctx["ajaxnav"] = True
     if url != "":
         jsonctx["url"] = url
+    jsonctx["norefresh"] = norefresh
     return HttpResponse(simplejson.dumps(jsonctx), mimetype="application/json")
 
 def decode(s, encodings=('utf8', 'latin1', 'windows-1252', 'ascii'), charset=None):

static/js/form.js

@@ -49,15 +49,19 @@ function ajax_submit(event) {
   new Request({
     method: form.get("method"),
     data: data,
-    onSuccess: function(responseText) {
+    onSuccess: function(responseText){
       var response = JSON.decode(responseText);
 
       if (response.status == "ko") {
-        $(document.body).set("html", response.content);
-	$(document.body).addEvent("submit", ajax_submit);
-	if ($defined(error_callbacks[myid])) {
-	  error_callbacks[myid]();
-	}
+        if ($defined(response.norefresh) && response.norefresh == true) {
+          $("error").set("html", response.error);
+        } else {
+          $(document.body).set("html", response.content);
+	  $(document.body).addEvent("submit", ajax_submit);
+	  if ($defined(error_callbacks[myid])) {
+	    error_callbacks[myid]();
+	  }
+        }
       } else {
         if ($defined(response.ajaxnav)) {
           if ($defined(response.url)) {