Argument in registered_taxonomy hook is lost.

[Toro_Unit]

$args in register_taxonomy is passed to registered_taxonomy hook without being processed.
Default parameters are missing.

This change breaks compatibility.

[swissspidy]

Hey there,

Thanks a ton for your report!

Like in register_post_type() we should pass an un-casted $taxonomy_object (of type WP_Taxonomy) to the filter instead.

Introduced in #36224 / [38747].

[swissspidy]

Note: The ​dev-note would need to be adjusted accordingly.

[Toro_Unit]

@swissspidy

I also agree with your idea.

Plugin developers need to implement the code.

<?php
add_action( 'registered_taxonomy', 'my_registered_taxonomy', 10, 3 );
function my_registered_taxonomy( $taxonomy, $object_type, $args ) {
        $args = (array) $args; /* for Compatibility */

        /* code... */

}

What do you think about compatibility breaking?

[Toro_Unit]

fix param comments

[Toro_Unit]

Sorry 38765.3.diff is a mistake.

[swissspidy]

What do you think about compatibility breaking?

That's why we announce such changes on make/core and change inline documentation appropriately.

[swissspidy]

For the registered_post_type hook, we could easily do this because $args was already an object there. That's not the case for registered_taxonomy. What we could do:

1) Replace $args with WP_Taxonomy, add to dev-note
2) Cast the taxonomy object to an array
3) Implement the ArrayAccess interface in WP_Taxonomy

@boonebgorges As you have reviewed #36224 previously, what's your take on this?

[Toro_Unit]

@swissspidy

If implement the ArrayAccess interface in WP_Taxonomy, should WP_Post_Type do the same ?

[swissspidy]

Replying to Toro_Unit:

@swissspidy

If implement the ArrayAccess interface in WP_Taxonomy, should WP_Post_Type do the same ?

There's no need for WP_Post_Type to implement this interface. And if there is one, it should be handled in a separate ticket. But let's first talk about possible options before going into details for specific solutions.

[Toro_Unit]

implements ArrayAccess

[Toro_Unit]

Replying to @swissspidy :

All right.

About backwards compatibility, I found a helpful comment.

https://core.trac.wordpress.org/ticket/20103#comment:9

[peterwilsoncc]

ArrayAccess knocks out the use of array_merge() and a bunch of other array functionality. As that's the raison d'etre for $args arrays, I'm hesitant to do anything other than cast to an array before passing to the filter. The backcompat implications are too big.

[swissspidy]

@peterwilsoncc Thanks for weighing in! Considering that we're so close to RC, cast to an array seems like the safest approach.

[peterwilsoncc]

In 38765.6.diff​:

• makes the arguments used to register the taxonomy available as a property
• passed arguments property to the registered_taxonomy hook

Made the args a property to avoid the need to recursively cast to an array.

​diff of 4.6.1 arguments and 4.7 arguments passed to the hook.

[boonebgorges]

38765.6.diff​ seems fine to me.

[peterwilsoncc]

In 38765.7.diff​, returns $args['name'] which I'd missed in .6.

[peterwilsoncc]

38765.8.diff​ now without test code.

[swissspidy]

It seems like there are a few failing tests with 38765.8.diff​.

[peterwilsoncc]

@swissspidy this passes and i don't know what I was thinking this-morning, labels and caps have been objects fro some time :)

[peterwilsoncc]

In 39283:

Taxonomy: Update register_taxonomy hook to use WP_Taxonomy object.

Casts WP_Taxonomy to an array for passing to the register_taxonomy hook. This maintains backward compatibility with the processed arguments used prior to WordPress 4.7.

Fixes #38765.