We need to remove the related js test: https://github.com/joomla/test-javascript/tree/master/src/caption

I'll do a PR for that (but I still have to convert at least one basic script test there as an example, so give me some time for this...)

Captions should work as before because we actually moved to use figure and figcaption long ago. The JS was kept and loaded for B/C reasons with existing old articles.

New articles created in 3.8 do not use figure and figcaption. So what is the plan to convert all articles on upgrade

@brianteeman are you referring to intro/full image or the images in the full text field (editor)?

intro/full is the only one that has caption

So we can update their jLayouts to use figcaption/figure tags

This I think should be ok

<?php if (isset($images->image_fulltext) && !empty($images->image_fulltext)) : ?>
	<?php $imgfloat = empty($images->float_fulltext) ? $params->get('float_fulltext') : $images->float_fulltext; ?>
	<figure class="pull-<?php echo htmlspecialchars($imgfloat); ?> item-image">
		<img src="<?php echo htmlspecialchars($images->image_fulltext); ?>" alt="<?php echo htmlspecialchars($images->image_fulltext_alt); ?>" itemprop="image"/>
		<?php if ($images->image_fulltext_caption) :
			echo '<figcaption class="caption">'
					. htmlspecialchars($images->image_fulltext_caption)
				. '</figcaption>';
		endif; ?>
	</figure>
<?php endif; ?>

@brianteeman Since J3.2.2 the image button in the editor should create figure and figcaption elements. My PR back then was #2664 and when I tested it now it still works this way.
Of course, articles created before that time would have "broken" captions as long as you don't load a replacement JS (eg using a plugin) or edit the articles to use figure. There is no way we can do that on updates.
I assumed we had changed the into/fullimages layouts as well, but apparently that was never done? Of course that then needs to be done in this PR as well. No need to update anything on the content for this.

Or do I miss something?

I assumed we had changed the into/fullimages layouts as well, but apparently that was never done? Of course that then needs to be done in this PR as well. No need to update anything on the content for this.

yes that is all that needs to be done

My PR back then was #2664 and when I tested it now it still works this way.

Well it's not working like that anymore with the new media manager. ?
We need to fix that ASAP

Adjusted the layouts for the intro and full image to use figure and figcaption tags.
The figure is always added, regardless if there is a caption or not.

@brianteeman I've read that the figure element should have an aria role=group if there is a caption included. I've added that one. Maybe you can verify if that is correct.

@Bakual see https://developer.paciellogroup.com/blog/2011/08/html5-accessibility-chops-the-figure-and-figcaption-elements/

@brianteeman I can't say I understand everything written there. My knowledge about accessibility is quite limited. I got the part about the role=group from a german site (https://wiki.selfhtml.org/wiki/HTML/Textstrukturierung/figure).
What I got from your article is that the caption should be before the image, and in fact with the caption.js currently it's like that as well. So I moved that around.

@brianteeman are the changes ok regarding accessibility?
@dgrammatiko can you fix the related js tests from the testing repo?
@Bakual can you fix the conflicts here that we can move to the next step?

better to ask the accessibility team than me

Rebased PR and fixed the conflict

@Bakual goupin roles are used to identify related form controls, so I do not see a necessity in figure/figcaption

Ok, I'll remove that part then. Makes code simpler ?

Opened a pr joomla/test-javascript#7 in the testing repo to remove the caption.js tests. Once this is merged, we can merge this one here too.

Once #20449 is merged, the JS tests will always be fetched from the correct branch instead of the latest version.

Great work, thanks @Bakual!

Follow up PR to deprecate it in J3: #20451

Beware #20503

BTW, I do not understand what is behind the idea that the caption should be before the image.
My test show that with this template it displays above the image, which is a nonsense.

@infograf768 it is more a matter of taste but figcaption can be used above or below (or both).

@chmst
I understand it is possible to display the caption above or below with figcaption but, nevertheless, the most common usage is below.
Will make another PR after #20503 is merged.

!Idea: let's have some options in the backend for the placement of the caption...

PS. I'm joking ?