Improve Edit/View behavior

[gnestor]

Follow up from #2203 (comment)

This makes the default path edit for files so that all files can edited. If a file is binary or otherwise uneditable, a user can still edit it and they will see the following error:

Error: [FILE] is not UTF-8 encoded
Saving is disabled.
See Console for more details.

They're browser won't crash or anything, so no harm, no foul.

If a file's MIME type matches text/html or the whitelist of viewable extensions (a list of browser-supported extensions borrowed from https://support.google.com/chromebook/answer/183093?hl=en), then it will use the view path by default.

[rgbkrk]

This seems like a pretty reasonable choice for edit.

[billgreenwald]

Sorry if this isnt the right thread for this question:

Since upgrading to jupyterhub 5.2.0, the default option for .pdf's switched from view to edit. Is this intentional?

Separately, where is this "white list" located, so that I could manually tell the hub to view .pdf's instead of edit them.

Thanks!

[takluyver]

(i'm guessing you mean jupyter notebook - jupyterhub is on version 0.8.1)

The list of viewable filetypes is here:

notebook/notebook/static/tree/js/notebooklist.js

Lines 558 to 561 in bbf0ead

	var html_types = ['htm', 'html', 'xhtml', 'xml', 'mht', 'mhtml'];
	var media_extension = ['3gp', 'avi', 'mov', 'mp4', 'm4v', 'm4a', 'mp3', 'mkv', 'ogv', 'ogm', 'ogg', 'oga', 'webm', 'wav'];
	var image_type = ['bmp', 'gif', 'jpg', 'jpeg', 'png', 'webp'];
	var other_type = ['ico'];

PDF should probably be on it.