Large templates and multi-part template content with many templates can take a very long time to load and in usability tests users thought that something was broken, clicking on the edit button many times.
This is the follow up to the investigation: T296386: Measure potential performance regression between the old and new VE template dialog sidebar
- Open dialog immediately after user clicks on edit or double clicks on an existing template
- When content needs time to load, show the header and blank overlay with OOUI widget Progress bar (indeterminate). Determine loading time for which it makes sense to show loading bar to assure user that loading is in progress vs adding to visual noise (if loading happens quickly).
- Replace overlay with template content when it's fully loaded.
Nice to have
- The overlay is 90% opacity and shows the elements behind as they load
Mocks and specs
Progress bar is 70% width of the dialog and is centered in both directions
90% Opacity (Nice to have):