How to show spinner until the tinymce editor is shown on the page

[chelsumz007]

Is your feature request related to a problem? Please describe. How to show spinner until the tinymce editor is shown on the page

Describe the solution you'd like A clear and concise description of what you want to happen.

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

[exalate-issue-sync[bot]]

Ref: INT-2591

[jscasca]

That can be a bit tricky but if you have your own spinner implementation the callback needs to be placed in init_instance_callback to know the editor has finished loading