Plugin sometimes ignores 'if' statement of function at first attempt.

[ethicalrevolution]

Quick summary

I have a function to add a hidden link to the start of the content of posts that are in specific categories on my Wordpress site.

The idea is that this link is visible on Fedi/Mastodon and gives followers a chance to click directly to the post to read it on the website rather than read a long post on Mastodon.

The issue I'm having is that the ActivityPub plugin sometimes ignores that this function is for specific categories only and includes the hidden link on posts from categories that are not included in the function. When this happens I have to revert the post to draft, wait 15 seconds or so and then republish it for the ActivitiyPub plugin to then update the federated post and correctly display the post on Fedi/Mastodon without the hidden link.

Steps to reproduce

The function:

function hidden_link($content){
  //add text at start of WordPress posts
  if( in_category( array( 1, 488, 498, 499 ) ) ) {
    $before = '<p class="hidden">' . __( '<a href="' . get_permalink() . '">[Read in full on NHAM]</a>' ) . '</p>';

    //modify the incoming content 
    $content = $before . $content ; 
  } 
  return $content; 
}
 
add_filter( 'the_content', 'hidden_link' );

Site owner impact

Fewer than 20% of the total website/platform users

Severity

Moderate

What other impact(s) does this issue have?

No response

If a workaround is available, please outline it here.

No response

[ethicalrevolution]

(I realise there is the option to add a similar style link via shortcode in the ActivityPub plugin settings but that is for all posts, and I need the link to only display on posts from specific categories.)

[pfefferle]

Content might be used differently, depending on your settings, the length of the text and other factors. If you want to get sure that it will always be added and only to the ActivityPub representation, you should use the activitypub_activity_object_array or the activitypub_activity_{$class}_object_array where $class is the class name of the Activity(Object). You can find them here:

wordpress-activitypub/includes/activity/class-generic-object.php

Line 273 in de352b0

$array = \apply_filters( 'activitypub_activity_object_array', $array, $class, $this->id, $this );

[ethicalrevolution]

Thank you Matthias, I'll do my best!

[pfefferle]

Let me know if you need support!

[ethicalrevolution]

I think I do! Is it just a case of tweaking the function? If so I'm not really sure which bit to change.

[ethicalrevolution]

I've tried the code below instead ... but I get this error (line 83 is the first line of the code at the bottom of this post):

Your PHP code changes were not applied due to an error on line 83 of file wp-content/themes/samsty2/functions.php. Please fix and try saving again.

Uncaught ArgumentCountError: Too few arguments to function hidden_link(), 1 passed in wp-includes/class-wp-hook.php on line 326 and exactly 4 expected in wp-content/themes/samsty2/functions.php:83
Stack trace:
#0 wp-includes/class-wp-hook.php(326): hidden_link(Array)
#1 wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)
#2 wp-content/plugins/activitypub/includes/activity/class-base-object.php(647): apply_filters('activitypub_act...', Array, 'blog', NULL, Object(Activitypub\Model\Blog))
#3 wp-content/plugins/activitypub/includes/class-blocks.php(268): Activitypub\Activity\Base_Object->to_array()
#4 wp-includes/class-wp-block.php(537): Activitypub\Blocks::render_follow_me_block(Array, '', Object(WP_Block))
#5 wp-includes/blocks.php(2191): WP_Block->render()
#6 /home/nhamcouk/public_ht

...

The new attempt at the code:

function hidden_link($array, $class, $activity_id, $id){
  //add text at start of WordPress posts
  if( in_category( array( 1, 488, 498, 499 ), $id ) ) {
    $before = '<p class="hidden">' . __( '<a href="' . get_permalink() . '">[Read in full on NHAM]</a>' ) . '</p>';
    //modify the incoming content 
    $array['content'] = $before . $content ; 
  } 
	return $array;

}
 
add_filter( 'activitypub_activity_object_array', 'hidden_link' );

[ethicalrevolution]

Ooh hang on ... we may have cracked it ... thanks to Stefan Bohacek ... added a little to the last line to make it:

function hidden_link($array, $class, $activity_id, $id){
  //add text at start of WordPress posts
  if( in_category( array( 1, 488, 498, 499 ), $id ) ) {
    $before = '<p class="hidden">' . __( '<a href="' . get_permalink() . '">[Read in full on NHAM]</a>' ) . '</p>';
    //modify the incoming content 
    $array['content'] = $before . $content ; 
  } 
	return $array;

}
 
add_filter( 'activitypub_activity_object_array', 'hidden_link', 99, 4 );

I've just done a test post and it appears to have worked! Does it look right to you Matthias @pfefferle?

[pfefferle]

the only thing $id might also be the id of a comment or an unknown post type, but the collision possibilities might be low.

[ethicalrevolution]

Ah, is there any way to avoid that? i.e. can I remove $id at all? (And what would likely happen if there was a 'collision'?)

[ethicalrevolution]

Bad news... I just did a test post in one of the selected categories and the [Read in full on NHAM] snippet was not inserted, so the function isn't working in its current format. The screenshot shows the post on Mastodon without the text or link from the function inserted.

[pfefferle]

You only added it to the content, and it seems that you published an Article, so Mastodon shows the summary :)

Can you try to add it to the content and summary?

[ethicalrevolution]

Hmm no, that doesn't seem to work either. Amended code below.

Also note my ActivityPub plugin is set to display the content rather than the excerpt (see screenshot).

function hidden_link($array, $class, $activity_id, $id){
  //add text at start of WordPress posts
  if( in_category( array( 1, 161 ), $id ) ) {
    $before = '<p class="hidden">' . __( '<a href="' . get_permalink($id) . '">[Test Post - Ignore Me]</a>' ) . '</p>';
    //modify the incoming content 
    $content = get_the_content($id);
    $summary  = get_the_excerpt($id);

    $array['content'] = $before . $content ; 
    $array['summary '] = $before . $summary  ; 
  } 
	return $array;

}
 
add_filter( 'activitypub_activity_object_array', 'hidden_link', 99, 4 );