Batch upload media after post editing is completed

[diegoreymendez]

Steps:

1. Insert an image into a post.
2. Quickly save the post before the image finishes uploading.
3. Reopen the post.

Current behaviour: the image will not show properly, because it's still pointing at the old local URL. Expected behaviour: we should probably let the user know that if they save before the image finishes uploading, the image will not be added to the post.

[diegoreymendez]

/cc @meremagee - For UX review, improvements, changes, etc.

[meremagee]

The production app currently displays the following

Instead of throwing an alert and/or discarding media upon state change, let's bundle media uploading with the post state change. In other words, when you're taken to the post list after hitting post/save, you'll see "UPLOADING..." progress indicator next to the post title. Let's just prolong this process to let media finish uploading before the post state is changed:

Down the road, we could add stages to the progress indicator to show the 2 processes more explicitly, like "media uploading..." then "saving post..."

[bummytime]

@meremagee I think for the 4.6 release, we should just uniformly implement the blocking dialog - not letting the user post until the upload is complete. I :heart: your solution, but fear that implementing it will be a can of worms and technically goes against our code freeze rulez.

/cc @diegoreymendez

[bummytime]

Sorry, should've pinged @thianhlu here too....

[thianhlu]

Let's keep the blocking alert for now. Let's change the text.

You are currently uploading media. Please wait until this completes.

[bummytime]

Renaming this issue to provide a little more clarity.

[bummytime]

(This is in reference to @meremagee's comment above)