Image Block: breaks when setting the align

[chiilog]

Describe the bug

If I set settings.attributes.align.default = 'right';, when it breaks.

To reproduce

import { addFilter } from '@wordpress/hooks';
addFilter(
    'blocks.registerBlockType',
    'my-plugin/support-default-image-align',
    ( settings, name ) => {
        if ( name !== 'core/image' ) {
            return settings;
        }
        settings.attributes.align.default = 'right';

        return settings;
    }
);

Expected behavior

I expected that set default alignments.

Screenshots

Additional context

• Gutenberg 6.5

[skorasaurus]

I'm able to still reproduce on Gutenberg 9.5.2.

[paaljoachim]

@talldan Dan are you able to take a look?

Thanks.

[talldan]

It worked fine for me, so not really able to help:

@chiilog Is this still happening for you?

[5n]

@talldan Hi, I'm also able to probably still reproduce on Gutenberg 10.1.1.
The issue seems to be that the value of default alignment is not saved in block’s markup.

If you don't set default alignment:

<!-- wp:image -->
<figure class="wp-block-image"><img alt=""/></figure>
<!-- /wp:image -->

If you set default alignment as 'right':

<!-- wp:image -->
<div class="wp-block-image"><figure class="alignright"><img alt=""/></figure></div>
<!-- /wp:image -->

It works fine for new blocks, but not for existing blocks.

[talldan]

I see, yes, changing the default alignment would invalidate existing blocks that don't have that alignment. That is the expected behavior.

I think your code would need to add a deprecation to the image block to handle that (https://developer.wordpress.org/block-editor/developers/block-api/block-deprecation/).

But how you do this would depend on why you want to align images right. That's some context that is missing in this issue.

• If this is for a plugin, what you're trying to achieve might not be the best idea. The users images shouldn't all be unexpectedly aligned to the right without it being an explicit user action.
• If this is for your own site or a site you manage, you probably want some kind of migration script for existing content. Otherwise you have to click through every post saving it. (Proper server-side APIs for block modification #6494)