Refactor error messages.

When we didn't pass the redirect parameter in exceptions.handle() then
'_alert_message.html' template is used to displays the error messages.
If details are empty in a case but it still shows the 'Details' href
which is wrong and this patch adds a condition in that template to fix
that issue.

This patch also fix review comment of change-id
5081359295 and define a constant for
'\u2026' and use it in all files.

Note: '\u2026' is used for unicode glyph representing '...'.

Closes-Bug: #1893305

Partially-Implements blueprint refactor-error-messages

Change-Id: If4409a1245c983fb51712c6c817c11e884916694
Co-Author: Ivan Kolodyazhny <e0ne@e0ne.info>

horizon/exceptions.py

@@ -31,6 +31,8 @@ from horizon import messages
 
 LOG = logging.getLogger(__name__)
 
+SEPERATOR = '\u2026'
+
 
 class HorizonReporterFilter(SafeExceptionReporterFilter):
     """Error report filter that's always active, even in DEBUG mode."""
@@ -261,7 +263,7 @@ HANDLE_EXC_METHODS = [
 
 
 def _append_detail(message, details):
-    return encoding.force_text(message) + '\u2026' + \
+    return encoding.force_text(message) + SEPERATOR + \
         encoding.force_text(details)
 
 

horizon/static/horizon/js/horizon.messages.js

@@ -49,6 +49,12 @@ horizon.alert = function (type, message, extra_tags, details) {
     };
   var this_alert = $(template.render(params)).hide().prependTo("#main_content .messages").fadeIn(100);
   horizon.autoDismissAlert(this_alert);
+
+  // NOTE: messages template engine doesn't support conditional rendering yet
+  // So it's a temporary work-around to hide details link when details is empty.
+  if (details === undefined || details === "") {
+    this_alert.find("#details_link").remove();
+  }
   return this_alert;
 };
 

horizon/templates/horizon/client_side/_alert_message.html

@@ -15,7 +15,8 @@
     [[/safe]]
     [[^safe]]
       [[message]]
-      <a href="#message_details"  data-toggle="collapse" data-target="#message_details">Details</a>
+      <a id="details_link" href="#message_details"  data-toggle="collapse"
+         data-target="#message_details">Details</a>
       <div id="message_details" class="collapse">
       [[details]]
       </div>

horizon/templatetags/splitfilter.py

@@ -12,9 +12,11 @@
 
 from django import template
 
+from horizon import exceptions
+
 register = template.Library()
 
 
 @register.filter(name='split_message')
 def split_message(value):
-    return value.split('\u2026')
+    return value.split(exceptions.SEPERATOR)

horizon/test/unit/test_exceptions.py

@@ -26,7 +26,8 @@ class HandleTests(test.TestCase):
         # 'Because the container is not empty, it can not be deleted.'
 
         expected = ['error', force_text(translated_unicode +
-                                        '\u2026' + translated_unicode), '']
+                                        exceptions.SEPERATOR +
+                                        translated_unicode), '']
 
         req = self.request
         req.META['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest'
@@ -80,7 +81,7 @@ class HandleTests(test.TestCase):
         message = u"Couldn't make the thing"
         exc_msg = u"Exception string"
         details = "custom detail message"
-        expected = ['error', message + '\u2026' + details, '']
+        expected = ['error', message + exceptions.SEPERATOR + details, '']
         req = self.request
         req.META['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest'