Trac 57575 "Sandbox" MU Plugin

test-trac-57575-mu-sandbox.php

<?php
/**
 * Trac 57575: WP_HTML_Tag_Processor Testing
 *   https://core.trac.wordpress.org/ticket/57575
 *
 * Also refer to unit test suite for additional examples:
 *   https://github.com/WordPress/wordpress-develop/tree/5b4ad8fa5634177102ee5771a2b7edfd86927f8b/tests/phpunit/tests/html
 *
 * ******************************** WARNING ***********************************
 * * This plugin intentionally prevents the normal WordPress UI from loading. *
 * * Do not install if you are not familiar with mu-plugin management.        *
 * ****************************************************************************
 *
 * To install and test:
 *   1. Copy this file into your test site's wp-content/mu-plugins/ directory.
 *   2. Load your test site's homepage.
 *   3. View the rendered output, as well as the markup (via View Source).
 *
 * To uninstall:
 *   Remove this file from wp-content/mu-plugins/.
 */

// Set initial HTML to process.
$html = '<h2 class="old-class">h2 heading</h2><p>This class\'s <code>old-class</code> will be replaced with <code>new-class</code>.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
if ( $tags->next_tag( [ 'tag_name' => 'h2' ] ) ) {
	$tags->set_attribute( 'class', 'new-class' );
}
$html = $tags->get_updated_html();


// Keep working with the result.
$html .= '<h2 class="find-class">h2 heading</h2><p>This <code>&lt;h2&gt;</code> is found by class <code>find-class</code>, and updated with <code>found-class</code>.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
$tags->next_tag( [ 'class_name' => 'find-class' ] );
$tags->add_class( 'found-class' );
$html = $tags->get_updated_html();


// Now modify the second h2.
$html .= '<p>Now update this heading\'s <code>style</code> attribute to red text.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
$tags->next_tag( 'h2' );
$tags->next_tag( 'H2' ); // Also validate that tag case doesn't matter.
$tags->set_attribute( 'style', 'color:red;' );
$html = $tags->get_updated_html();


// Now modify each paragraph's style, skipping the first one.
$html .= '<p>Now change all paragraphs to italic.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
$p_count = 0;
while ( $tags->next_tag( 'p' ) ) {
	$tags->set_attribute( 'style', 'font-style:italic;' );
	$p_count++;
}
$html = $tags->get_updated_html();


// Now update the third paragraph's style.
$html .= '<p>Now change the third paragraph to bold using <code>seek()</code>.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
$tags->next_tag( 'p' );
$tags->set_bookmark( 'first p' );
$tags->next_tag( 'p' );
$tags->set_bookmark( 'second p' );
$tags->next_tag( 'p' );
$tags->set_bookmark( 'third p' );
$tags->next_tag( 'p' );
$tags->set_bookmark( 'fourth p' );
$tags->next_tag( 'p' );
$tags->set_bookmark( 'fifth p' );

$tags->seek( 'third p' );
$tags->set_attribute( 'style', 'font-weight:bold;' );

$html = $tags->get_updated_html();


// Now update the second paragraph's style.
$html .= '<p>Now unset the second paragraph\'s style using <code>$match_offset</code>.</p>';

$tags = new WP_HTML_Tag_Processor( $html );
$tags->next_tag( [ 'tag_name' => 'p', 'match_offset' => 2 ] );
$tags->remove_attribute( 'style' );

$html = $tags->get_updated_html();


// Output final result.
printf( "<h1>Trac 57575: <code>WP_HTML_Tag_Processor</code> Testing</h1>\n%s", $html );

exit; // View source to validate resultant HTML.