Contributor users receive an upload error when attempting to set a Featured Image

[rickybanister]

Contributors are not permitted to upload media, however they are still displayed the 'featured image' widget on post-new.php.

Furthermore, if they attempt to upload media in the media overlay their upload fails and displays an upload error

The featured image widget should be hidden from contributors. If the widget is removed, the upload error becomes irrelevant.

[rickybanister]

Additionally, media items that were previously uploaded by admin users do not load for contributors.

Contributors see the spinner, but no media ever loads.

[SergeyBiryukov]

Related: #19817, #19834.

[ericlewis]

Wow. So if you're a contributor, you can't create a post with any media in it. That's a serious editorial workflow issue.

I think we should add 'upload_files' to the contributor role. Thoughts?

[kpdesign]

Replying to ericlewis:

Wow. So if you're a contributor, you can't create a post with any media in it. That's a serious editorial workflow issue.

I think we should add 'upload_files' to the contributor role. Thoughts?

I don't think we should add the upload_files cap to the Contributor role.

A Contributor can delete and edit their own posts, and read. They don't have the capability to publish their own post - any post they create has to be submitted for review.

The Contributor role only has a minimum level of trust. If a contributor is trusted enough to allow them to upload files, then their role should be changed to Author by the site admin.

The post editor doesn't show the Add Media button to contributors, so the Featured Image meta box should be hidden from that role as well.

[ericlewis]

Replying to kpdesign:

I don't think we should add the upload_files cap to the Contributor role.

I tend to agree with you after reading the discussion on #19834 (More Robust Capabilities for Attachments). I think this ticket is more or less a duplicate of that. However, as this cites a specific bug that needs to be fixed, let's leave this open and follow-up on the user capabilities discussion in that ticket.

[MikeHansenMe]

check if user can upload files

[ryan]

Upload error messages in the modal are not at all helpful. Another instance is failed video uploads. Even a tiny 3 second video upload will fail on most hosts. Our error messages are useless dead ends. We need to see these messages in the context of flows like this and make them relevant and useful.

[ryan]

This prompted me to do a visual record as a contributor.

​http://make.wordpress.org/flow/2014/07/10/setting-featured-image-as-a-contributor-macnchrome-4-0-beta1/

28327.diff removes the featured image meta box for contributors. Administrators still see the box and all seems well when setting a featured image. I did not test with other roles. Looks good. Other tickets to improve error messages for this flow and video upload flow would be great.

[ryan]

#28367

[SergeyBiryukov]

#29113 was marked as a duplicate.

[SergeyBiryukov]

So, contributors cannot upload new images by default, and cannot use existing images either, since wp_ajax_query_attachments()​ requires upload_files capability.

28327.diff​ looks good to me.

[SergeyBiryukov]

Since we don't show the Add Media button​ if the user cannot upload files, I guess there's no point in calling wp_enqueue_media() either. See 28327.2.diff​.

[wonderboymusic]

In 29402:

Don't show the Featured Image metabox for users with the contributor role. Do enqueue media so that TinyMCE previews work for YouTube embeds, etc.

Props SergeyBiryukov.
Fixes #28327.

[SergeyBiryukov]

The props should have gone to MikeHansenMe.