advanced-excerpt.php

<?php
/*
Plugin Name: Advanced Excerpt
Plugin URI: http://basvd.com/code/advanced-excerpt/
Description: Several improvements over WP's default excerpt. The size of the excerpt can be limited using character or word count, and HTML markup is not removed.
Version: 4.1.1
Author: Bas van Doren
Author URI: http://basvd.com/

Copyright 2007 Bas van Doren

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

$GLOBALS['advanced_excerpt_version'] = '4.1.1';
$GLOBALS['advanced_excerpt_folder'] = basename( plugin_dir_path( __FILE__ ) );

class AdvancedExcerpt {
	// Plugin configuration
	public $name;
	public $text_domain;
	public $options;
	public $default_options = array(
		'length' => 40,
		'use_words' => 1,
		'no_custom' => 1,
		'no_shortcode' => 1,
		'finish_word' => 0,
		'finish_sentence' => 0,
		'ellipsis' => '&hellip;',
		'read_more' => 'Read the rest',
		'add_link' => 0,
		'allowed_tags' => array( '_all' )
	);

	// Basic HTML tags (determines which tags are in the checklist by default)
	public static $options_basic_tags = array(
		'a', 'abbr', 'acronym', 'b', 'big',
		'blockquote', 'br', 'center', 'cite', 'code', 'dd', 'del', 'div', 'dl', 'dt',
		'em', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', 'img', 'ins',
		'li', 'ol', 'p', 'pre', 'q', 's', 'small', 'span', 'strike', 'strong', 'sub',
		'sup', 'table', 'td', 'th', 'tr', 'u', 'ul'
	);

	// Almost all HTML tags (extra options)
	public static $options_all_tags = array(
		'a', 'abbr', 'acronym', 'address', 'applet',
		'area', 'b', 'bdo', 'big', 'blockquote', 'br', 'button', 'caption', 'center',
		'cite', 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl',
		'dt', 'em', 'fieldset', 'font', 'form', 'frame', 'frameset', 'h1', 'h2', 'h3',
		'h4', 'h5', 'h6', 'hr', 'i', 'iframe', 'img', 'input', 'ins', 'isindex', 'kbd',
		'label', 'legend', 'li', 'map', 'menu', 'noframes', 'noscript', 'object',
		'ol', 'optgroup', 'option', 'p', 'param', 'pre', 'q', 's', 'samp', 'script',
		'select', 'small', 'span', 'strike', 'strong', 'style', 'sub', 'sup', 'table',
		'tbody', 'td', 'textarea', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u', 'ul',
		'var'
	);

	// Singleton
	private static $inst = null;
	public static function Instance( $new = false ) {
		if ( self::$inst == null || $new ) {
			self::$inst = new AdvancedExcerpt();
		}
		return self::$inst;
	}

	private function __construct() {
		$this->name = strtolower( get_class() );
		$this->text_domain = $this->name;
		$this->load_options();
		$this->plugin_version = $GLOBALS['advanced_excerpt_version'];
		$this->plugin_folder_name = $GLOBALS['advanced_excerpt_folder'];

		load_plugin_textdomain( $this->text_domain, false, dirname( plugin_basename( __FILE__ ) ) );
		register_activation_hook( __FILE__, array( $this, 'install' ) );

		add_action( 'admin_menu', array( $this, 'add_pages' ) );

		// Replace the default filter (see /wp-includes/default-filters.php)
		//remove_filter('get_the_excerpt', 'wp_trim_excerpt');
		// Replace everything
		remove_all_filters( 'get_the_excerpt' );
		add_filter( 'get_the_excerpt', array( $this, 'filter' ) );
	}

	public function add_pages() {
		$options_page = add_options_page( __( "Advanced Excerpt Options", $this->text_domain ), __( "Excerpt", $this->text_domain ), 'manage_options', 'options-' . $this->name, array( $this, 'page_options' ) );
		// Scripts
		add_action( 'admin_print_scripts-' . $options_page, array( $this, 'page_script' ) );
	}

	public function page_script() {
		$version = defined('SCRIPT_DEBUG') && SCRIPT_DEBUG ? time() : $this->plugin_version;
		$plugins_url = trailingslashit( plugins_url() ) . trailingslashit( $this->plugin_folder_name );
		$src = $plugins_url . 'advanced-excerpt.js';
		wp_enqueue_script( 'advanced-excerpt-script', $src, array( 'jquery' ), $version, true );
	}

	public function filter( $text ) {
		// Extract options (skip collisions)
		if ( is_array( $this->options ) ) {
			extract( $this->options, EXTR_SKIP );
			$this->options = null; // Reset
		}
		extract( $this->default_options, EXTR_SKIP );

		// Avoid custom excerpts
		if ( !empty( $text ) && !$no_custom )
			return $text;

		// Get the full content and filter it
		$text = get_the_content( '' );
		if ( 1 == $no_shortcode )
			$text = strip_shortcodes( $text );
		$text = apply_filters( 'the_content', $text );

		// From the default wp_trim_excerpt():
		// Some kind of precaution against malformed CDATA in RSS feeds I suppose
		$text = str_replace( ']]>', ']]&gt;', $text );

		// Determine allowed tags
		if ( !isset( $allowed_tags ) )
			$allowed_tags = self::$options_all_tags;

		if ( isset( $exclude_tags ) )
			$allowed_tags = array_diff( $allowed_tags, $exclude_tags );

		// Strip HTML if allow-all is not set
		if ( !in_array( '_all', $allowed_tags ) ) {
			if ( count( $allowed_tags ) > 0 )
				$tag_string = '<' . implode( '><', $allowed_tags ) . '>';
			else
				$tag_string = '';
			$text = strip_tags( $text, $tag_string );
		}

		// Create the excerpt
		$text = $this->text_excerpt( $text, $length, $use_words, $finish_word, $finish_sentence );

		// Add the ellipsis or link
		$text = $this->text_add_more( $text, $ellipsis, ( $add_link ) ? $read_more : false );

		return $text;
	}

	public function text_excerpt( $text, $length, $use_words, $finish_word, $finish_sentence ) {
		$tokens = array();
		$out = '';
		$w = 0;

		// Divide the string into tokens; HTML tags, or words, followed by any whitespace
		// (<[^>]+>|[^<>\s]+\s*)
		preg_match_all( '/(<[^>]+>|[^<>\s]+)\s*/u', $text, $tokens );
		foreach ( $tokens[0] as $t ) { // Parse each token
			if ( $w >= $length && !$finish_sentence ) { // Limit reached
				break;
			}
			if ( $t[0] != '<' ) { // Token is not a tag
				if ( $w >= $length && $finish_sentence && preg_match( '/[\?\.\!]\s*$/uS', $t ) == 1 ) { // Limit reached, continue until ? . or ! occur at the end
					$out .= trim( $t );
					break;
				}
				if ( 1 == $use_words ) { // Count words
					$w++;
				} else { // Count/trim characters
					$chars = trim( $t ); // Remove surrounding space
					$c = strlen( $chars );
					if ( $c + $w > $length && !$finish_sentence ) { // Token is too long
						$c = ( $finish_word ) ? $c : $length - $w; // Keep token to finish word
						$t = substr( $t, 0, $c );
					}
					$w += $c;
				}
			}
			// Append what's left of the token
			$out .= $t;
		}

		return trim( force_balance_tags( $out ) );
	}

	public function text_add_more( $text, $ellipsis, $read_more ) {
		// New filter in WP2.9, seems unnecessary for now
		//$ellipsis = apply_filters('excerpt_more', $ellipsis);

		if ( $read_more )
			$ellipsis .= sprintf( ' <a href="%s" class="read_more">%s</a>', get_permalink(), $read_more );

		$pos = strrpos( $text, '</' );
		if ( $pos !== false ) {
			// Inside last HTML tag
			$text = substr_replace( $text, $ellipsis, $pos, 0 );
		} else {
			// After the content
			$text .= $ellipsis;
		}

		return $text;
	}

	public function install() {
		foreach ( $this->default_options as $k => $v ) {
			add_option( $this->name . '_' . $k, $v );
		}
	}

	private function load_options() {
		foreach ( $this->default_options as $k => $v ) {
			$this->default_options[$k] = get_option( $this->name . '_' . $k, $v );
		}
	}

	private function update_options() {
		$length       = (int) $_POST[$this->name . '_length'];
		$use_words    = ( 'on' == $_POST[$this->name . '_use_words'] ) ? 1 : 0;
		$no_custom    = ( 'on' == $_POST[$this->name . '_no_custom'] ) ? 1 : 0;
		$no_shortcode = ( 'on' == $_POST[$this->name . '_no_shortcode'] ) ? 1 : 0;
		$finish_word     = ( 'on' == $_POST[$this->name . '_finish_word'] ) ? 1 : 0;
		$finish_sentence = ( 'on' == $_POST[$this->name . '_finish_sentence'] ) ? 1 : 0;
		$add_link     = ( 'on' == $_POST[$this->name . '_add_link'] ) ? 1 : 0;

		// TODO: Drop magic quotes (deprecated in php 5.3)
		$ellipsis  = ( get_magic_quotes_gpc() == 1 ) ? stripslashes( $_POST[$this->name . '_ellipsis'] ) : $_POST[$this->name . '_ellipsis'];
		$read_more = ( get_magic_quotes_gpc() == 1 ) ? stripslashes( $_POST[$this->name . '_read_more'] ) : $_POST[$this->name . '_read_more'];

		$allowed_tags = array_unique( (array) $_POST[$this->name . '_allowed_tags'] );

		update_option( $this->name . '_length', $length );
		update_option( $this->name . '_use_words', $use_words );
		update_option( $this->name . '_no_custom', $no_custom );
		update_option( $this->name . '_no_shortcode', $no_shortcode );
		update_option( $this->name . '_finish_word', $finish_word );
		update_option( $this->name . '_finish_sentence', $finish_sentence );
		update_option( $this->name . '_ellipsis', $ellipsis );
		update_option( $this->name . '_read_more', $read_more );
		update_option( $this->name . '_add_link', $add_link );
		update_option( $this->name . '_allowed_tags', $allowed_tags );

		$this->load_options();
?>
        <div id="message" class="updated fade"><p>Options saved.</p></div>
    <?php
	}

	public function page_options() {
		if ( 'POST' == $_SERVER['REQUEST_METHOD'] ) {
			check_admin_referer( $this->name . '_update_options' );
			$this->update_options();
		}

		extract( $this->default_options, EXTR_SKIP );

		$ellipsis  = htmlentities( $ellipsis );
		$read_more = htmlentities( $read_more );

		$tag_list = array_unique( self::$options_basic_tags + $allowed_tags );
		sort( $tag_list );
		$tag_cols = 5;
?>
<div class="wrap">
    <div id="icon-options-general" class="icon32"><br /></div>
    <h2><?php
		_e( "Advanced Excerpt Options", $this->text_domain );
		?></h2>
    <form method="post" action="">
    <?php
		if ( function_exists( 'wp_nonce_field' ) )
			wp_nonce_field( $this->name . '_update_options' );
?>

        <table class="form-table">
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_length">
                <?php _e( "Excerpt Length:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_length" type="text"
                           id="<?php echo $this->name; ?>_length"
                           value="<?php echo $length; ?>" size="2"/>
                    <input name="<?php echo $this->name; ?>_use_words" type="checkbox"
                           id="<?php echo $this->name; ?>_use_words" value="on"<?php
		echo ( 1 == $use_words ) ? ' checked="checked"' : ''; ?>/>
                           <?php _e( "Use words?", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_ellipsis">
                <?php _e( "Ellipsis:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_ellipsis" type="text"
                           id="<?php echo $this->name; ?>_ellipsis"
                           value="<?php echo $ellipsis; ?>" size="5"/>
                    <?php _e( '(use <a href="http://www.w3schools.com/tags/ref_entities.asp">HTML entities</a>)', $this->text_domain ); ?>
                    <br />
                    <?php _e( "Will substitute the part of the post that is omitted in the excerpt.", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_length">
                <?php _e( "Finish:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_finish_word" type="checkbox"
                           id="<?php echo $this->name; ?>_finish_word" value="on"<?php
		echo ( 1 == $finish_word ) ? ' checked="checked"' : ''; ?>/>
                           <?php _e( "Word", $this->text_domain ); ?><br/>
                    <input name="<?php echo $this->name; ?>_finish_sentence" type="checkbox"
                           id="<?php echo $this->name; ?>_finish_sentence" value="on"<?php
		echo ( 1 == $finish_sentence ) ? ' checked="checked"' : ''; ?>/>
                           <?php _e( "Sentence", $this->text_domain ); ?>
                    <br />
                    <?php _e( "Prevents cutting a word or sentence at the end of an excerpt. This option can result in (slightly) longer excerpts.", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_read_more">
                <?php  _e( "&lsquo;Read-more&rsquo; Text:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_read_more" type="text"
                           id="<?php echo $this->name; ?>_read_more" value="<?php echo $read_more; ?>" />
                    <input name="<?php echo $this->name; ?>_add_link" type="checkbox"
                           id="<?php echo $this->name; ?>_add_link" value="on" <?php
		echo ( 1 == $add_link ) ? 'checked="checked" ' : ''; ?>/>
                           <?php _e( "Add link to excerpt", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_no_custom">
                <?php _e( "No Custom Excerpts:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_no_custom" type="checkbox"
                           id="<?php echo $this->name; ?>_no_custom" value="on" <?php
		echo ( 1 == $no_custom ) ? 'checked="checked" ' : ''; ?>/>
                           <?php _e( "Generate excerpts even if a post has a custom excerpt attached.", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><label for="<?php echo $this->name; ?>_no_shortcode">
                <?php _e( "Strip Shortcodes:", $this->text_domain ); ?></label></th>
                <td>
                    <input name="<?php echo $this->name; ?>_no_shortcode" type="checkbox"
                           id="<?php echo $this->name; ?>_no_shortcode" value="on" <?php
		echo ( 1 == $no_shortcode ) ? 'checked="checked" ' : ''; ?>/>
                           <?php _e( "Remove shortcodes from the excerpt. <em>(recommended)</em>", $this->text_domain ); ?>
                </td>
            </tr>
            <tr valign="top">
                <th scope="row"><?php _e( "Keep Markup:", $this->text_domain ); ?></th>
                <td>
                    <table id="<?php echo $this->name; ?>_tags_table">
                        <tr>
                            <td colspan="<?php echo $tag_cols; ?>">
    <input name="<?php echo $this->name; ?>_allowed_tags[]" type="checkbox"
           value="_all" <?php echo ( in_array( '_all', $allowed_tags ) ) ? 'checked="checked" ' : ''; ?>/>
           <?php _e( "Don't remove any markup", $this->text_domain ); ?>
                            </td>
                        </tr>
<?php
		$i = 0;
		foreach ( $tag_list as $tag ):
			if ( $tag == '_all' )
				continue;
			if ( 0 == $i % $tag_cols ):
?>
                        <tr>
<?php
				endif;
			$i++;
?>
                            <td>
    <input name="<?php echo $this->name; ?>_allowed_tags[]" type="checkbox"
           value="<?php echo $tag; ?>" <?php
		echo ( in_array( $tag, $allowed_tags ) ) ? 'checked="checked" ' : ''; ?>/>
    <code><?php echo $tag; ?></code>
                            </td>
<?php
		if ( 0 == $i % $tag_cols ):
			$i = 0;
		echo '</tr>';
		endif;
		endforeach;
		if ( 0 != $i % $tag_cols ):
?>
                          <td colspan="<?php echo $tag_cols - $i; ?>">&nbsp;</td>
                        </tr>
<?php
		endif;
?>
                    </table>
                    <a href="" id="<?php echo $this->name; ?>_select_all">Select all</a>
                    / <a href="" id="<?php echo $this->name; ?>_select_none">Select none</a><br />
                    More tags:
                    <select name="<?php echo $this->name; ?>_more_tags" id="<?php echo $this->name; ?>_more_tags">
<?php
		foreach ( self::$options_all_tags as $tag ):
?>
                        <option value="<?php echo $tag; ?>"><?php echo $tag; ?></option>
<?php
		endforeach;
?>
                    </select>
                    <input type="button" name="<?php echo $this->name; ?>_add_tag" id="<?php echo $this->name; ?>_add_tag" class="button" value="Add tag" />
                </td>
            </tr>
        </table>
        <p class="submit"><input type="submit" name="Submit" class="button-primary"
                                 value="<?php _e( "Save Changes", $this->text_domain ); ?>" /></p>
    </form>
</div>
<?php
	}

}

AdvancedExcerpt::Instance();

// Do not use outside the Loop!
function the_advanced_excerpt( $args = '', $get = false ) {
	if ( !empty( $args ) && !is_array( $args ) ) {
		$args = wp_parse_args( $args );

		// Parse query style parameters
		if ( isset( $args['ellipsis'] ) )
			$args['ellipsis'] = urldecode( $args['ellipsis'] );

		if ( isset( $args['allowed_tags'] ) )
			$args['allowed_tags'] = preg_split( '/[\s,]+/', $args['allowed_tags'] );

		if ( isset( $args['exclude_tags'] ) ) {
			$args['exclude_tags'] = preg_split( '/[\s,]+/', $args['exclude_tags'] );
		}
	}
	// Set temporary options
	AdvancedExcerpt::Instance()->options = $args;

	if ( $get )
		return get_the_excerpt();
	else
		the_excerpt();
}