TextformatterPagination.module

<?php

/**
 * ProcessWire Pagination Textformatter
 *
 * ProcessWire 2.x 
 * Copyright (C) 2014 by Ryan Cramer 
 * Licensed under GNU/GPL v2, see LICENSE.TXT
 * 
 * http://processwire.com
 *
 */

class TextformatterPagination extends Textformatter {

	public static function getModuleInfo() {
		return array(
			'title' => 'Pagination', 
			'version' => 3, 
			'summary' => "Provides pagination capability within a block of copy. Put 5+ hyphens '-----' on a single line (within paragraph tags) for regular pagination, or '----- Your Text' on a single line for named pagination. See the README for more.", 
			'href' => 'https://github.com/ryancramerdesign/TextformatterPagination', 
			'author' => 'Ryan Cramer', 
			'requires' => 'MarkupPagerNav'
		); 
	}

	/**
	 * Pagination options
	 *
	 * You may also include any options present in MarkupPagerNav's options list
	 *
	 * Populate this array from your /site/config.php with: 
	 * $config->TextformatterPagination = array( ... ); 
	 *
	 */
	protected $options = array(
		'titleListMarkup' => "<hr /><ol class='TextformatterPagination'>{out}</ol>", 
		'titleItemMarkup' => "<li><a href='{url}'>{out}</a></li>", 
		'titleCurrentItemMarkup' => "<li>{out}</li>", 
		'titleNextMarkup' => "<p><strong>Next: <a href='{url}'>{out}</a> &raquo;</strong></p>", 
		'useNumberPagination' => true, // Whether to use MarkupPagerNav style numbered pagination
		'useTitlePagination' => true, // Whether to use a Title pagination list, when available
		'useTitleNext' => true, // Whether to use "Next: [title]" links above Title Pagination, when available
		'titlePaginationFirst' => true, // Whether to display Title pagination above Numbered pagination
		'throw404' => true, // Throw a 404 exception if invalid pagination is accessed?
		);

	protected $populatePagination = true; 

	protected $initialized = false; 

	/**
	 * Process the text and insert pagination
	 *
	 */
	public function formatValue(Page $page, Field $field, &$value) {

		if(!$this->initialized) {
			if(is_array($this->wire('config')->TextformatterPagination)) {
				$this->options = array_merge($this->options, $this->wire('config')->TextformatterPagination); 
			}
			$this->initialized = true; 
		}

		$key = '~~~PAG~~~';
		if(strpos($value, '-----') === false) return; // quick exit
		if(strpos($value, $key) !== false) return;

		if(!$page->template->allowPageNum) { 
			if($page->editable()) $value = $this->getAdminError($page) . $value;
			return;
		}

		if(stripos($value, 'pagination-off-all') !== false && preg_match('{>\s*pagination-off-all\s*<}i', $value)) {
			$this->populatePagination = false; 	
		}

		// paragraph version
		$value = preg_replace('{<p>\s*-----+\s*(.*?)</p>}i', $key . '$1~~~' . "\t", $value); 

		// headline version
		$value = preg_replace('{<(h\d)>\s*-----+\s*(.+?)</\\1>}i', $key . '$2~~~' . "\t\n<$1>$2</$1>", $value); 

		if(strpos($value, $key) === false) return;

		$blocks = explode($key, $value); 
		if(!count($blocks)) return;

		if(empty($blocks[0])) array_shift($blocks); 

		$titles = array();
		$hasTitles = false; 

		foreach($blocks as $k => $v) {
			$pos = strpos($v, "~~~\t"); 	
			if($pos === false && !$k) {
				// first item, with no named title at top: use page title
				$titles[$k] = $page->title; 
				continue; 
			}
			$title = trim(substr($v, 0, $pos)); 
			$titles[$k] = trim($title); 
			if(strlen($title)) $hasTitles = true; 
			$blocks[$k] = substr($v, $pos+4); 
		}

		$numPages = count($blocks); 
		$pageNum = ($this->wire('input')->pageNum - 1); 

		if(!isset($blocks[$pageNum])) {
			if($this->options['throw404']) throw new Wire404Exception();
			$blocks[$pageNum] = '';
		}

		$value = $blocks[$pageNum]; 
		$numberPagination = '';
		$titlePagination = '';

		// values we will set to $page->TextformatterPagination variable
		$extras = array(
			'numPages' => $numPages, 
			'pageNum' => $pageNum, // zero-based page number
			'numberPagination' => '', 
			'titlePagination' => '',
			'title' => isset($titles[$pageNum]) ? $titles[$pageNum] : '', // current title
			'titles' => $titles, 
			'titleNextLink' => ''
			); 

		if($this->options['useNumberPagination']) {
			$numberPagination = $this->getNumberPagination($page, $blocks, $pageNum, $extras);
		}

		if($hasTitles && $this->options['useTitlePagination']) {
			$titlePagination = $this->getTitlePagination($page, $titles, $pageNum, $extras); 
		}

		$this->populateTokens($value, $extras); 

		if($this->populatePagination) { 
			if($this->options['titlePaginationFirst']) {
				$value .= "$titlePagination$numberPagination";
			} else {
				$value .= "$numberPagination$titlePagination";
			}
		}

		// set a value to the page to let the developer know pagination is active
		// as well as to give them the opportunity to re-use any of the pagination
		// links if they want to (like at the top of the page)
		$page->set('TextformatterPagination', $extras);
	}

	/**
	 * Look for tokens in $value and replace with pagination data when found
	 *
	 */
	protected function populateTokens(&$value, &$extras) {

		// these tokens consume the surrounding tag
		$tokens = array(
			'pagination-titles' => $extras['titlePagination'], 
			'pagination-titles-next' => $extras['titleNextLink'],
			'pagination-numbers' => $extras['numberPagination'], 
			'pagination-off-all' => '', 
			'pagination-off' => '', 
			);

		foreach($tokens as $tokenKey => $tokenValue) {
			if(stripos($value, $tokenKey) === false) continue; 
			if($tokenKey == 'pagination-off') $this->populatePagination = false; 
			$value = preg_replace('{<([a-z]+[0-9]?)>\s*' . $tokenKey . '\s*</\\1>}si', $tokenValue, $value); 
		}

		// these tokens do not consume the surrounding tag (nor do they require one)
		$tokens = array(
			'pagination-current' => $extras['pageNum']+1,
			'pagination-total' => $extras['numPages'], 
			'pagination-title' => $extras['title'], 
			);

		foreach($tokens as $tokenKey => $tokenValue) {
			if(stripos($value, $tokenKey) === false) continue; 
			$value = preg_replace('{\b' . $tokenKey . '\b}i', $tokenValue, $value); 
		}
	}

	/**
	 * Render the title pagination
	 *
	 */
	protected function getTitlePagination(Page $page, array $titles, $pageNum, &$extras) {

		$prefix = $this->wire('config')->pageNumUrlPrefix;
                if(!$prefix) $prefix = 'page';
		$out = '';
		$nextOut = '';

		foreach($titles as $k => $title) {
			if(empty($title)) continue; 
			$url = $k > 0 ? (rtrim($page->url, '/') . "/$prefix" . ($k+1)) : $page->url; 
			$markup = $k == $pageNum ? $this->options['titleCurrentItemMarkup'] : $this->options['titleItemMarkup']; 
			$out .= str_replace(array('{url}', '{out}'), array($url, $title), $markup); 
			if($k == $pageNum+1) {
				$nextOut = str_replace(array('{url}', '{out}'), array($url, $title), $this->options['titleNextMarkup']); 
			}
		}

		$out = str_replace('{out}', $out, $this->options['titleListMarkup']); 
		$extras['titlePagination'] = $out; 
		$extras['titleNextLink'] = $nextOut; 
		if($this->options['useTitleNext']) $out = $nextOut . $out; 
		return $out; 
	}

	/**
	 * Render the numbered pagination
	 *
	 */
	protected function getNumberPagination(Page $page, array $blocks, $pageNum, &$extras) {
		$pager = $this->wire('modules')->get('MarkupPagerNav'); 
		$pageArray = new PageArray();
		$pageArray->setStart($pageNum); 
		$pageArray->setTotal(count($blocks)); 
		$pageArray->setLimit(1); 
		$out = $pager->render($pageArray, $this->options); 
		$extras['numberPagination'] = $out; 
		return $out; 
	}

	/**
	 * Tell the admin they need to enable page numbers for the template
	 *
	 */
	protected function getAdminError(Page $page) {
		return "<p style='background: crimson; color: white; padding: 0.5em;'>
			Pagination Textformatter Alert: 
			Please enable <i>page numbers</i> for template <b>$page->template</b> in  
			<u>Setup</u> &gt; <u>Templates</u> &gt; <u>URLs</u>.
			This message only appears to editors of this page.
			</p>
			";
	}
}