Source

File: wp-includes/class-wp-editor.php

public static function editor( $content, $editor_id, $settings = array() ) {
		$set            = self::parse_settings( $editor_id, $settings );
		$editor_class   = ' class="' . trim( esc_attr( $set['editor_class'] ) . ' wp-editor-area' ) . '"';
		$tabindex       = $set['tabindex'] ? ' tabindex="' . (int) $set['tabindex'] . '"' : '';
		$default_editor = 'html';
		$buttons        = '';
		$autocomplete   = '';
		$editor_id_attr = esc_attr( $editor_id );

		if ( $set['drag_drop_upload'] ) {
			self::$drag_drop_upload = true;
		}

		if ( ! empty( $set['editor_height'] ) ) {
			$height = ' style="height: ' . (int) $set['editor_height'] . 'px"';
		} else {
			$height = ' rows="' . (int) $set['textarea_rows'] . '"';
		}

		if ( ! current_user_can( 'upload_files' ) ) {
			$set['media_buttons'] = false;
		}

		if ( self::$this_tinymce ) {
			$autocomplete = ' autocomplete="off"';

			if ( self::$this_quicktags ) {
				$default_editor = $set['default_editor'] ? $set['default_editor'] : wp_default_editor();
				// 'html' is used for the "Text" editor tab.
				if ( 'html' !== $default_editor ) {
					$default_editor = 'tinymce';
				}

				$buttons .= '<button type="button" id="' . $editor_id_attr . '-tmce" class="wp-switch-editor switch-tmce"' .
					' data-wp-editor-id="' . $editor_id_attr . '">' . _x( 'Visual', 'Name for the Visual editor tab' ) . "</button>\n";
				$buttons .= '<button type="button" id="' . $editor_id_attr . '-html" class="wp-switch-editor switch-html"' .
					' data-wp-editor-id="' . $editor_id_attr . '">' . _x( 'Text', 'Name for the Text editor tab (formerly HTML)' ) . "</button>\n";
			} else {
				$default_editor = 'tinymce';
			}
		}

		$switch_class = 'html' === $default_editor ? 'html-active' : 'tmce-active';
		$wrap_class   = 'wp-core-ui wp-editor-wrap ' . $switch_class;

		if ( $set['_content_editor_dfw'] ) {
			$wrap_class .= ' has-dfw';
		}

		echo '<div id="wp-' . $editor_id_attr . '-wrap" class="' . $wrap_class . '">';

		if ( self::$editor_buttons_css ) {
			wp_print_styles( 'editor-buttons' );
			self::$editor_buttons_css = false;
		}

		if ( ! empty( $set['editor_css'] ) ) {
			echo $set['editor_css'] . "\n";
		}

		if ( ! empty( $buttons ) || $set['media_buttons'] ) {
			echo '<div id="wp-' . $editor_id_attr . '-editor-tools" class="wp-editor-tools hide-if-no-js">';

			if ( $set['media_buttons'] ) {
				self::$has_medialib = true;

				if ( ! function_exists( 'media_buttons' ) ) {
					require ABSPATH . 'wp-admin/includes/media.php';
				}

				echo '<div id="wp-' . $editor_id_attr . '-media-buttons" class="wp-media-buttons">';

				/**
				 * Fires after the default media button(s) are displayed.
				 *
				 * @since 2.5.0
				 *
				 * @param string $editor_id Unique editor identifier, e.g. 'content'.
				 */
				do_action( 'media_buttons', $editor_id );
				echo "</div>\n";
			}

			echo '<div class="wp-editor-tabs">' . $buttons . "</div>\n";
			echo "</div>\n";
		}

		$quicktags_toolbar = '';

		if ( self::$this_quicktags ) {
			if ( 'content' === $editor_id && ! empty( $GLOBALS['current_screen'] ) && 'post' === $GLOBALS['current_screen']->base ) {
				$toolbar_id = 'ed_toolbar';
			} else {
				$toolbar_id = 'qt_' . $editor_id_attr . '_toolbar';
			}

			$quicktags_toolbar = '<div id="' . $toolbar_id . '" class="quicktags-toolbar"></div>';
		}

		/**
		 * Filters the HTML markup output that displays the editor.
		 *
		 * @since 2.1.0
		 *
		 * @param string $output Editor's HTML markup.
		 */
		$the_editor = apply_filters(
			'the_editor',
			'<div id="wp-' . $editor_id_attr . '-editor-container" class="wp-editor-container">' .
			$quicktags_toolbar .
			'<textarea' . $editor_class . $height . $tabindex . $autocomplete . ' cols="40" name="' . esc_attr( $set['textarea_name'] ) . '" ' .
			'id="' . $editor_id_attr . '">%s</textarea></div>'
		);

		// Prepare the content for the Visual or Text editor, only when TinyMCE is used (back-compat).
		if ( self::$this_tinymce ) {
			add_filter( 'the_editor_content', 'format_for_editor', 10, 2 );
		}

		/**
		 * Filters the default editor content.
		 *
		 * @since 2.1.0
		 *
		 * @param string $content        Default editor content.
		 * @param string $default_editor The default editor for the current user.
		 *                               Either 'html' or 'tinymce'.
		 */
		$content = apply_filters( 'the_editor_content', $content, $default_editor );

		// Remove the filter as the next editor on the same page may not need it.
		if ( self::$this_tinymce ) {
			remove_filter( 'the_editor_content', 'format_for_editor' );
		}

		// Back-compat for the `htmledit_pre` and `richedit_pre` filters.
		if ( 'html' === $default_editor && has_filter( 'htmledit_pre' ) ) {
			/** This filter is documented in wp-includes/deprecated.php */
			$content = apply_filters_deprecated( 'htmledit_pre', array( $content ), '4.3.0', 'format_for_editor' );
		} elseif ( 'tinymce' === $default_editor && has_filter( 'richedit_pre' ) ) {
			/** This filter is documented in wp-includes/deprecated.php */
			$content = apply_filters_deprecated( 'richedit_pre', array( $content ), '4.3.0', 'format_for_editor' );
		}

		if ( false !== stripos( $content, 'textarea' ) ) {
			$content = preg_replace( '%</textarea%i', '&lt;/textarea', $content );
		}

		printf( $the_editor, $content );
		echo "\n</div>\n\n";

		self::editor_settings( $editor_id, $set );
	}