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Opened 20 months ago
Last modified 2 months ago
#62628 new defect (bug)
Server and client directive negation logic should align
| Reported by: | jonsurrell | Owned by: | |
|---|---|---|---|
| Priority: | normal | Milestone: | Awaiting Review |
| Component: | Interactivity API | Version: | 6.5 |
| Severity: | normal | Keywords: | has-patch |
| Cc: | Focuses: |
Description
Interactivity API directives allow for a negation prefix !. Values with this prefix should be negated.
The server side and client side negation logic both rely on rudimentary ! negation. This means that the negation logic depends on PHP and JavaScript behavior which do not always agree and cause differences in server/client rendering of the same data.
For example, with this state:
<?php wp_interactivity_state( 'example', array( 'emptyArray' => array(), 'stringZero' => '0', ) );
And the following HTML with directives:
<div data-wp-interactive="example"> <div data-wp-bind--data-test="!state.emptyArray"></div> <div data-wp-bind--data-test="!state.stringZero"></div> </div>
This is the server render render:
<div data-test="true" data-wp-bind--data-test="!state.emptyArray"></div> <div data-test="true" data-wp-bind--data-test="!state.stringZero"></div>
While the client renders the following:
<div data-test="false" data-wp-bind--data-test="!state.emptyArray"></div> <div data-test="false" data-wp-bind--data-test="!state.stringZero"></div>
Change History (4)
#2
@
20 months ago
This resource describes the behavior, "0" and [] may be the only problematic values:
This ticket was mentioned in PR #11804 on WordPress/wordpress-develop by @shreya0shrivastava.
2 months ago
#4
- Keywords has-patch added; needs-patch removed
The Interactivity API supports a negation prefix ! in directive values. However, the server-side negation logic relies on PHP's native boolean casting, which disagrees with JavaScript on two values:
[](empty array): falsy in PHP, truthy in JavaScript.'0'(string zero): falsy in PHP, truthy in JavaScript.
This causes a mismatch between server and client rendering of the same state, breaking the hydration contract of the Interactivity API.
This fix updates the server-side negation logic in WP_Interactivity_API::evaluate() to use JavaScript-compatible truthiness rules for these two cases, ensuring server and client rendering agree.
Trac ticket: https://core.trac.wordpress.org/ticket/62628
## Use of AI Tools
I've added this to the 6.8 iteration issue.