Let amp-live-list for comments be opt-in

[westonruter]

We should add a theme support flag for comments_live_list to control whether or not comment submission is intercepted. Without flag, default full-page-reload behavior should be retained to allow themes without amp-live-list in comments to work normally.

The theme can do:

add_theme_support( 'amp', array(
	'comments_live_list' => true,
) );

And then the plugin can read it like this:

<?php
add_filter( 'comment_post_redirect', function( $url, $comment ) {
	$theme_support = get_theme_support( 'amp' );

	// Return with simply success when amp-live-list will show newly-posted comment.
	if ( ! empty( $theme_support['comments_live_list'] ) ) {
		wp_send_json_success();
	}

	// Add the comment ID to the URL to force AMP to refresh the page.
	$url = add_query_arg( 'comment', $comment->comment_ID, $url );

	return $url;
}, PHP_INT_MAX, 2 );

This will allow amp support to be added to an existing theme without requiring its comments template to be retrofitted with amp-live-list.

Alternatively, if we think that amp-live-list should really be the default we want to always be used, then there could instead be an opt-out flag.

[westonruter]

Naturally the wp_send_json_success() bit would change in light of #1020 (comment)

[DavidCramer]

Thanks @westonruter .

[westonruter]

To test without opt-in, making a comment at: https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/amp/

Should result in a page refresh with a URL like https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/amp/?comment=34#comment-34

For a native AMP site where the flag is present, there should be no refresh and instead the Update Comments button should appear to update the live list: https://dev-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/

[westonruter]

Three issues I see:

1. When in paired mode, if I submit the comment at https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/amp/ then it will redirect me to the non-AMP article. The comment_post_redirect filter should be making sure that if paired mode is enabled that it redirects to the AMP version of the post instead.

2. Related: when in non-paired mode such as at https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/#respond I cannot submit the form. Why? Because the amp-runtime script is erroneously getting enqueued. This results in:

3. When submitting a comment from a site I can see now that _wp_amp_action_xhr_converted really should be used to determine whether the logic in AMP_Theme_Support::handle_xhr_request() runs.

[westonruter]

To test, try commenting on AMP article in paired mode: https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/amp/

And try commenting on the non-AMP version of the article: https://paired-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/

In both cases, the page should reload after submitting with the comment scrolled into view.

Also try commenting on AMP article in native mode: https://dev-ampconfdemo.pantheonsite.io/2018/02/06/are-you-there-lebron-its-me-lebron-a-superstars-ultimate-pep-talk/

[kienstra]

Request For Testing

Hi @csossi,
Are you available to test this, using @westonruter's instructions above?

[csossi]

yes, will be on this today/tomorrow @kienstra @westonruter

[csossi]

• when I post a comment on native mode site, the display refreshes with the "awaiting moderation" message appearing just below the comment form - doesn't reposition anywhere. Can I assume that's the intent here, @westonruter ?

[westonruter]

@csossi After submitting the comment, it should look like this with the New Comment(s) button momentarily appearing (within 15 seconds) above the form:

Upon clicking the New Comments button it should scroll you up to your posted comment, and look like this: