PHP Warning: Undefined array key "widget_id"

[Gnodesign]

Describe the bug
On PHP 8+, WP Job Manager triggers warnings for an undefined array key widget_id in WP_Job_Manager_Widget::get_cached_widget() and cache_widget(). The code assumes $args['widget_id'] is always present. The widget should gracefully handle missing widget_id values (e.g. by skipping caching) to avoid PHP warnings and ensure PHP 8+ compatibility.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'WP Dashboard -> Appearance -> Widgets"
2. Add "Recent/Featured Jobs" widget
3. Save Changes
4. See error in debug.log

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only WP Job Manager plugin is active.
• This bug happens with a default WordPress theme active.
• I can reproduce this bug consistently using the steps above.

WordPress Environment

• WordPress Version: 6.9
• WP Job Manager Version: 2.4.0
• PHP Version: 8+

[Gnodesign]

This issue is caused by the following functions:

WP-Job-Manager/includes/class-wp-job-manager-widget.php

Lines 83 to 114 in 1613449

	public function get_cached_widget( $args ) {
	$cache = wp_cache_get( $this->widget_id, 'widget' );
	if ( ! is_array( $cache ) ) {
	$cache = [];
	}
	if ( isset( $cache[ $args['widget_id'] ] ) ) {
	echo $cache[ $args['widget_id'] ]; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
	return true;
	}
	return false;
	}
	/**
	* Caches the widget.
	*
	* @param array $args
	* @param string $content
	*/
	public function cache_widget( $args, $content ) {
	$cache = wp_cache_get( $this->widget_id, 'widget' );
	if ( ! is_array( $cache ) ) {
	$cache = [];
	}
	$cache[ $args['widget_id'] ] = $content;
	wp_cache_set( $this->widget_id, $cache, 'widget' );
	}

It can be resolved by defensively checking for a missing widget_id at the beginning of each function, and skipping caching when it’s not available:

if ( empty( $args['widget_id'] ) ) {
	return;
}

[Gnodesign]

Hi @donnchawp,
I have seen some progress on the plugin. Could we include this in the current batch of fixes of fixes as well? It continues to throw errors on PHP 8 and above.

[donnchawp]

Sorry @Gnodesign, I saw your message just after I merged the release PR. :(

Thanks for the detailed report though. I'll take a look tomorrow.

[Gnodesign]

Thanks for getting back to me, @donnchawp. That sounds good.

It might also be a good time to merge the visibility feature PR #2848 I submitted almost two years ago as well.

[Gnodesign]

Hi @donnchawp, would it be possible to include this as a hotfix? Users are moving to PHP 8+, and this issue is starting to affect them.

[masteradhoc]

@Gnodesign @donnchawp could you please check this PR #2923?

[Gnodesign]

Hi @masteradhoc, thanks for the PR. I reviewed the changes and everything works as expected. No errors were encountered. Feel free to merge it.