Custom Merge Tags

Hi here! We still try used this plugin for our project, now i try add custom merge tag for custom trigger, i used this manual https://docs.bracketspace.com/docs/registering-custom-triggers/ (it really good examples) but i have some problem with merge tags.
I try add merge tag like this

public function merge_tags() {
		$this->add_merge_tag( new \BracketSpace\Notification\Defaults\MergeTag\UrlTag( array(
			'slug'        => 'email',
			'name'        => __( 'User email', 'socialbet' ),
			'resolver'    => function( $trigger ) {
			return add_query_arg( 'source', $trigger->param_value, site_url() );
			//return trim($trigger->param_value);
			},
			'description' => __( 'Email пользователя', 'socialbet' ),
			'example'     => true,
		) ) );

    }

}

it’s work perfect with
return add_query_arg( ‘source’, $trigger->param_value, site_url() );
but then i try
return trim($trigger->param_value);
it’s return me NULL, so how i can return to merge tag just variable ?

what am I doing wrong ?

• This topic was modified 6 years, 3 months ago by redmonkey73.