More resistant javascript code

src/static/pretixpresale/js/ui/asynctask.js

@@ -1,4 +1,4 @@
-/*global $, waitingDialog, failsafe_gettext */
+/*global $, waitingDialog, gettext */
 var async_task_id = null;
 var async_task_timeout = null;
 var async_task_check_url = null;
@@ -10,7 +10,7 @@ function async_task_check() {
             'type': 'GET',
             'url': async_task_check_url,
             'success': async_task_check_callback,
-            'error': async_task_error,
+            'error': async_task_check_error,
             'context': this,
             'dataType': 'json'
         }
@@ -24,11 +24,32 @@ function async_task_check_callback(data, jqXHR, status) {
         return;
     }
     async_task_timeout = window.setTimeout(async_task_check, 250);
+    $("#loadingmodal p").text(gettext('Your request has been queued on the server and will now be ' +
+                                      'processed.'));
+}
+
+function async_task_check_error(jqXHR, textStatus, errorThrown) {
+    "use strict";
+    var c = $(jqXHR.responseText).filter('.container');
+    if (c.length > 0) {
+        waitingDialog.hide();
+        ajaxErrDialog.show(c.first().html());
+    } else {
+        if (jqXHR.status >= 400 && jqXHR.status < 500) {
+            waitingDialog.hide();
+            alert(gettext('An error of type {code} occured.').replace(/\{code\}/, jqXHR.status));
+        } else {
+            // 500 can be an application error or overload in some cases :(
+            $("#loadingmodal p").text(gettext('We currenctly cannot reach the server, but we keep trying.' +
+                                              ' Last error code: {code}').replace(/\{code\}/, jqXHR.status));
+            async_task_timeout = window.setTimeout(async_task_check, 5000);
+        }
+    }
 }
 
 function async_task_callback(data, jqXHR, status) {
     "use strict";
-    $(this).data('ajaxing', false);
+    $("body").data('ajaxing', false);
     if (data.redirect) {
         location.href = data.redirect;
         return;
@@ -36,17 +57,26 @@ function async_task_callback(data, jqXHR, status) {
     async_task_id = data.async_id;
     async_task_check_url = data.check_url;
     async_task_timeout = window.setTimeout(async_task_check, 100);
+
+    history.pushState({}, "Waiting", async_task_check_url.replace(/ajax=1/, ''));
 }
 
 function async_task_error(jqXHR, textStatus, errorThrown) {
     "use strict";
-    waitingDialog.hide();
-    // TODO: Handle status codes != 200
+    $("body").data('ajaxing', false);
     var c = $(jqXHR.responseText).filter('.container');
     if (c.length > 0) {
+        waitingDialog.hide();
         ajaxErrDialog.show(c.first().html());
     } else {
-        alert(failsafe_gettext('Unknown error.'));
+        if (jqXHR.status >= 400 && jqXHR.status < 500) {
+            waitingDialog.hide();
+            alert(gettext('An error of type {code} occured.').replace(/\{code\}/, jqXHR.status));
+        } else {
+            waitingDialog.hide();
+            alert(gettext('We currenctly cannot reach the server. Please try again. ' +
+                          'Error code: {code}').replace(/\{code\}/, jqXHR.status));
+        }
     }
 }
 
@@ -54,11 +84,12 @@ $(function () {
     "use strict";
     $("body").on('submit', 'form[data-asynctask]', function (e) {
         e.preventDefault();
-        if ($(this).data('ajaxing')) {
+        if ($("body").data('ajaxing')) {
             return;
         }
-        $(this).data('ajaxing', true);
-        waitingDialog.show(failsafe_gettext('We are processing your request …'));
+        async_task_id = null;
+        $("body").data('ajaxing', true);
+        waitingDialog.show(gettext('We are processing your request …'));
 
         $.ajax(
             {

src/static/pretixpresale/js/ui/cart.js

@@ -1,4 +1,4 @@
-/*global $,failsafe_gettext,failsafe_ngettext */
+/*global $,gettext,ngettext */
 
 var cart = {
     _deadline: null,
@@ -7,10 +7,10 @@ var cart = {
     draw_deadline: function () {
         var diff = Math.floor(cart._deadline.diff(moment()) / 1000 / 60);
         if (diff < 0) {
-            $("#cart-deadline").text(failsafe_gettext("The items in your cart are no longer reserved for you."));
+            $("#cart-deadline").text(gettext("The items in your cart are no longer reserved for you."));
             window.clearInterval(cart._deadline_interval);
         } else {
-            $("#cart-deadline").text(failsafe_ngettext(
+            $("#cart-deadline").text(ngettext(
                 "The items in your cart are reserved for you for one minute.",
                 "The items in your cart are reserved for you for {num} minutes.",
                 diff

src/static/pretixpresale/js/ui/main.js

@@ -1,12 +1,12 @@
 /*global $ */
 
-function failsafe_gettext(msgid) {
+function gettext(msgid) {
     if (typeof django !== 'undefined' && typeof django.gettext !== 'undefined') {
         return django.gettext(msgid);
     }
     return msgid;
 }
-function failsafe_ngettext(singular, plural, count) {
+function ngettext(singular, plural, count) {
     if (typeof django !== 'undefined' && typeof django.ngettext !== 'undefined') {
         return django.ngettext(singular, plural, count);
     }
@@ -54,7 +54,7 @@ var ajaxErrDialog = {
         "use strict";
         $("#ajaxerr").html(c);
         $("#ajaxerr .links").html("<a class='btn btn-default ajaxerr-close'>"
-                                  + failsafe_gettext("Close message") + "</a>");
+                                  + gettext("Close message") + "</a>");
         $("body").addClass("ajaxerr");
     },
     hide: function () {