I18N: Load translations just-in-time for custom themes and plugins.

In #34114, just-in-time (JIT) translation loading was implemented for projects hosted on WordPress.org. This is now expanded to all other plugins/themes.

Projects with a custom `Text Domain` and `Domain Path` header no longer need to call `load_plugin_textdomain()` or `load_theme_textdomain()`.

This reduces the risk of calling them too late, after some translation calls already happened, and generally makes it easier to properly internationalize a plugin or theme.

This moves the `get_plugin_data()` from `wp-admin/includes/plugin.php` to `wp-includes/functions.php` so it's available during the plugin loading process.

Props swissspidy.
Fixes #62244.

git-svn-id: https://develop.svn.wordpress.org/trunk@59461 602fd350-edb4-49c9-b593-d223f7449a82

Author: swissspidy

src/wp-admin/includes/plugin.php

@@ -6,221 +6,6 @@
  * @subpackage Administration
  */
 
-/**
- * Parses the plugin contents to retrieve plugin's metadata.
- *
- * All plugin headers must be on their own line. Plugin description must not have
- * any newlines, otherwise only parts of the description will be displayed.
- * The below is formatted for printing.
- *
- *     /*
- *     Plugin Name: Name of the plugin.
- *     Plugin URI: The home page of the plugin.
- *     Description: Plugin description.
- *     Author: Plugin author's name.
- *     Author URI: Link to the author's website.
- *     Version: Plugin version.
- *     Text Domain: Optional. Unique identifier, should be same as the one used in
- *          load_plugin_textdomain().
- *     Domain Path: Optional. Only useful if the translations are located in a
- *          folder above the plugin's base path. For example, if .mo files are
- *          located in the locale folder then Domain Path will be "/locale/" and
- *          must have the first slash. Defaults to the base folder the plugin is
- *          located in.
- *     Network: Optional. Specify "Network: true" to require that a plugin is activated
- *          across all sites in an installation. This will prevent a plugin from being
- *          activated on a single site when Multisite is enabled.
- *     Requires at least: Optional. Specify the minimum required WordPress version.
- *     Requires PHP: Optional. Specify the minimum required PHP version.
- *     * / # Remove the space to close comment.
- *
- * The first 8 KB of the file will be pulled in and if the plugin data is not
- * within that first 8 KB, then the plugin author should correct their plugin
- * and move the plugin data headers to the top.
- *
- * The plugin file is assumed to have permissions to allow for scripts to read
- * the file. This is not checked however and the file is only opened for
- * reading.
- *
- * @since 1.5.0
- * @since 5.3.0 Added support for `Requires at least` and `Requires PHP` headers.
- * @since 5.8.0 Added support for `Update URI` header.
- * @since 6.5.0 Added support for `Requires Plugins` header.
- *
- * @param string $plugin_file Absolute path to the main plugin file.
- * @param bool   $markup      Optional. If the returned data should have HTML markup applied.
- *                            Default true.
- * @param bool   $translate   Optional. If the returned data should be translated. Default true.
- * @return array {
- *     Plugin data. Values will be empty if not supplied by the plugin.
- *
- *     @type string $Name            Name of the plugin. Should be unique.
- *     @type string $PluginURI       Plugin URI.
- *     @type string $Version         Plugin version.
- *     @type string $Description     Plugin description.
- *     @type string $Author          Plugin author's name.
- *     @type string $AuthorURI       Plugin author's website address (if set).
- *     @type string $TextDomain      Plugin textdomain.
- *     @type string $DomainPath      Plugin's relative directory path to .mo files.
- *     @type bool   $Network         Whether the plugin can only be activated network-wide.
- *     @type string $RequiresWP      Minimum required version of WordPress.
- *     @type string $RequiresPHP     Minimum required version of PHP.
- *     @type string $UpdateURI       ID of the plugin for update purposes, should be a URI.
- *     @type string $RequiresPlugins Comma separated list of dot org plugin slugs.
- *     @type string $Title           Title of the plugin and link to the plugin's site (if set).
- *     @type string $AuthorName      Plugin author's name.
- * }
- */
-function get_plugin_data( $plugin_file, $markup = true, $translate = true ) {
-
-	$default_headers = array(
-		'Name'            => 'Plugin Name',
-		'PluginURI'       => 'Plugin URI',
-		'Version'         => 'Version',
-		'Description'     => 'Description',
-		'Author'          => 'Author',
-		'AuthorURI'       => 'Author URI',
-		'TextDomain'      => 'Text Domain',
-		'DomainPath'      => 'Domain Path',
-		'Network'         => 'Network',
-		'RequiresWP'      => 'Requires at least',
-		'RequiresPHP'     => 'Requires PHP',
-		'UpdateURI'       => 'Update URI',
-		'RequiresPlugins' => 'Requires Plugins',
-		// Site Wide Only is deprecated in favor of Network.
-		'_sitewide'       => 'Site Wide Only',
-	);
-
-	$plugin_data = get_file_data( $plugin_file, $default_headers, 'plugin' );
-
-	// Site Wide Only is the old header for Network.
-	if ( ! $plugin_data['Network'] && $plugin_data['_sitewide'] ) {
-		/* translators: 1: Site Wide Only: true, 2: Network: true */
-		_deprecated_argument( __FUNCTION__, '3.0.0', sprintf( __( 'The %1$s plugin header is deprecated. Use %2$s instead.' ), '<code>Site Wide Only: true</code>', '<code>Network: true</code>' ) );
-		$plugin_data['Network'] = $plugin_data['_sitewide'];
-	}
-	$plugin_data['Network'] = ( 'true' === strtolower( $plugin_data['Network'] ) );
-	unset( $plugin_data['_sitewide'] );
-
-	// If no text domain is defined fall back to the plugin slug.
-	if ( ! $plugin_data['TextDomain'] ) {
-		$plugin_slug = dirname( plugin_basename( $plugin_file ) );
-		if ( '.' !== $plugin_slug && ! str_contains( $plugin_slug, '/' ) ) {
-			$plugin_data['TextDomain'] = $plugin_slug;
-		}
-	}
-
-	if ( $markup || $translate ) {
-		$plugin_data = _get_plugin_data_markup_translate( $plugin_file, $plugin_data, $markup, $translate );
-	} else {
-		$plugin_data['Title']      = $plugin_data['Name'];
-		$plugin_data['AuthorName'] = $plugin_data['Author'];
-	}
-
-	return $plugin_data;
-}
-
-/**
- * Sanitizes plugin data, optionally adds markup, optionally translates.
- *
- * @since 2.7.0
- *
- * @see get_plugin_data()
- *
- * @access private
- *
- * @param string $plugin_file Path to the main plugin file.
- * @param array  $plugin_data An array of plugin data. See get_plugin_data().
- * @param bool   $markup      Optional. If the returned data should have HTML markup applied.
- *                            Default true.
- * @param bool   $translate   Optional. If the returned data should be translated. Default true.
- * @return array Plugin data. Values will be empty if not supplied by the plugin.
- *               See get_plugin_data() for the list of possible values.
- */
-function _get_plugin_data_markup_translate( $plugin_file, $plugin_data, $markup = true, $translate = true ) {
-
-	// Sanitize the plugin filename to a WP_PLUGIN_DIR relative path.
-	$plugin_file = plugin_basename( $plugin_file );
-
-	// Translate fields.
-	if ( $translate ) {
-		$textdomain = $plugin_data['TextDomain'];
-		if ( $textdomain ) {
-			if ( ! is_textdomain_loaded( $textdomain ) ) {
-				if ( $plugin_data['DomainPath'] ) {
-					load_plugin_textdomain( $textdomain, false, dirname( $plugin_file ) . $plugin_data['DomainPath'] );
-				} else {
-					load_plugin_textdomain( $textdomain, false, dirname( $plugin_file ) );
-				}
-			}
-		} elseif ( 'hello.php' === basename( $plugin_file ) ) {
-			$textdomain = 'default';
-		}
-		if ( $textdomain ) {
-			foreach ( array( 'Name', 'PluginURI', 'Description', 'Author', 'AuthorURI', 'Version' ) as $field ) {
-				if ( ! empty( $plugin_data[ $field ] ) ) {
-					// phpcs:ignore WordPress.WP.I18n.LowLevelTranslationFunction,WordPress.WP.I18n.NonSingularStringLiteralText,WordPress.WP.I18n.NonSingularStringLiteralDomain
-					$plugin_data[ $field ] = translate( $plugin_data[ $field ], $textdomain );
-				}
-			}
-		}
-	}
-
-	// Sanitize fields.
-	$allowed_tags_in_links = array(
-		'abbr'    => array( 'title' => true ),
-		'acronym' => array( 'title' => true ),
-		'code'    => true,
-		'em'      => true,
-		'strong'  => true,
-	);
-
-	$allowed_tags      = $allowed_tags_in_links;
-	$allowed_tags['a'] = array(
-		'href'  => true,
-		'title' => true,
-	);
-
-	/*
-	 * Name is marked up inside <a> tags. Don't allow these.
-	 * Author is too, but some plugins have used <a> here (omitting Author URI).
-	 */
-	$plugin_data['Name']   = wp_kses( $plugin_data['Name'], $allowed_tags_in_links );
-	$plugin_data['Author'] = wp_kses( $plugin_data['Author'], $allowed_tags );
-
-	$plugin_data['Description'] = wp_kses( $plugin_data['Description'], $allowed_tags );
-	$plugin_data['Version']     = wp_kses( $plugin_data['Version'], $allowed_tags );
-
-	$plugin_data['PluginURI'] = esc_url( $plugin_data['PluginURI'] );
-	$plugin_data['AuthorURI'] = esc_url( $plugin_data['AuthorURI'] );
-
-	$plugin_data['Title']      = $plugin_data['Name'];
-	$plugin_data['AuthorName'] = $plugin_data['Author'];
-
-	// Apply markup.
-	if ( $markup ) {
-		if ( $plugin_data['PluginURI'] && $plugin_data['Name'] ) {
-			$plugin_data['Title'] = '<a href="' . $plugin_data['PluginURI'] . '">' . $plugin_data['Name'] . '</a>';
-		}
-
-		if ( $plugin_data['AuthorURI'] && $plugin_data['Author'] ) {
-			$plugin_data['Author'] = '<a href="' . $plugin_data['AuthorURI'] . '">' . $plugin_data['Author'] . '</a>';
-		}
-
-		$plugin_data['Description'] = wptexturize( $plugin_data['Description'] );
-
-		if ( $plugin_data['Author'] ) {
-			$plugin_data['Description'] .= sprintf(
-				/* translators: %s: Plugin author. */
-				' <cite>' . __( 'By %s.' ) . '</cite>',
-				$plugin_data['Author']
-			);
-		}
-	}
-
-	return $plugin_data;
-}
-
 /**
  * Gets a list of a plugin's files.
  *