Custom Placeholder

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Easy Watermark

User Guide

Developer

Each placeholder is defined with a class responsible for replacing a specific string tag with a dynamic value. Placeholder class needs to extend EasyWatermark\Placeholders\Abstracts\Placeholder and should implement the following methods:
1.resolve - returning the value of the placeholder
2.validate - checking if the value is correct
3.sanitize - sanitizing the value
There are also 4 abstract placeholders available that implement the validate and sanitize methods for a given value type:
1.EasyWatermark\Placeholders\Abstracts\EmailPlaceholder
2.EasyWatermark\Placeholders\Abstracts\IntegerPlaceholder
3.EasyWatermark\Placeholders\Abstracts\StringPlaceholder
4.EasyWatermark\Placeholders\Abstracts\UrlPlaceholder
Placeholder class
use EasyWatermark\Placeholders\Abstracts\StringPlaceholder;
​
/**
 * Abstract placeholder
 */
class FavoriteColorPlaceholder extends StringPlaceholder {
​
	/**
	 * Constructor
	 *
	 * @return void
	 */
	public function __construct() {
​
		$this->slug    = 'favorite_color';
		$this->name    = __( 'Favorite color', 'textdomain' );
		$this->example = __( 'blue', 'textdomain' );
​
	}
​
	/**
	 * Resolves placeholder
	 *
	 * @param  EasyWatermark\Placeholders\Resolver $resolver Placeholders resolver instance.
	 * @return string
	 */
	public function resolve( $resolver ) {
​
		$user = wp_get_current_user();
		return get_user_meta( 'favorite_color', $user->ID );
​
	}
}
​
The above class will replace a %favorite_color% string in the watermark text with the value of a favorite_color meta for logged-in user.
Registering the Placeholder
/**
 * @param EasyWatermark\Placeholders\Resolver $resolver Placeholders resolver instance.
 */
add_action( 'easy-watermark/placeholders/load', function ( $resolver ) {
    // Add custom placeholder instance to the resolver.
    $resolver->add_placeholder( new FavoriteColorPlaceholder() );
} );

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Placeholders

Last modified 1yr ago

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Placeholder class

Registering the Placeholder