HTML.php

<?php
/**
	@file
	@brief Tools for working with HTML, mostly for output.
*/

namespace Edoceo\Radix;

class HTML
{
	/**
		Turns HTML into Formatted Text
		@param string $html
		@return text/plain of HTML that is stripped of tags and formatted pretty(ish)
	*/
	static function asText($html)
	{
		$er = error_reporting(0);
		$dom = new \DOMDocument();
		$dom->loadHTML($html);
		error_reporting($er);

		$text = self::_html2text_node($dom);

		return $text;
	}

	/**
		@param $html String of HTML, hopefully well formed
	*/
	static function stripComments($html)
	{
		return preg_replace('/<!\-\-(.*?)\-\->/ms', null, $html);
	}

	/**
		Recursive Utility function for html2text
		@param object $node
		@return string text/plain
	*/
	private static function _html2text_node($pn)
	{
		$node_post = null;
		$node_text = null;
		$nl = $pn->childNodes->length;
		for ($i=0; $i<$nl; $i++) {
			$cn = $pn->childNodes->item($i);
			//if ($cn == null) continue;
			// Process Nodes
			// echo sprintf('%s #%d/%d',$cn->nodeName,$this->_node_step,count($this->_node_post)) . "\n";

			// Analyse Specific Node Name
			switch ($cn->nodeName) {
			case 'a': // used to create a hyperlink
				$node_post.= ' <' . $cn->getAttribute('href') . '> ';
				break;
			// case 'abbr':
			case 'acronym':
				$x = $cn->getAttribute('title');
				if (!empty($x)) {
					$node_post = sprintf(' (%s)',$x);
				}
				break;
			// case 'applet':
			// case 'area':
			// case 'b': // deprecated
			// case 'base':
			// case 'basefont': // deprecated
			// case 'bdo':
			// case 'blackface': // deprecated
			case 'blockquote': // used to identify larger amounts of quoted text
				$node_post = "\n";
				break;
			// case 'big': // deprecated
			// case 'body':
			case 'br':
				$node_post = "\n";
				break;
			// case 'button': // used to create button controls for forms
			// case 'caption':
			// case 'center': // deprecated
			// case 'cite':
			// case 'code':
			// case 'col':  // @todo Check Align, Width
			// case 'colgroup': // @todo Check Align, Width
			case 'dd':
				$node_text.= "	";
				$node_post = "\n";
				break;
			// case 'del':
			// case 'dfn': // dfn - contains the defining instance of the enclosed term.
			// case 'dir': // deprecated
			// case 'div': // div - offers a generic way of grouping areas of content.
			case 'dl': // used to create a list where each item in the list comprises two parts: a term and a description.
				// $node_text.= "\n";
				$node_post = "\n";
				$node_pads = '  ';
				break;
			case 'dt': // dt - is a definition term for an item in a definition list
				$node_text.= "  ";
				$node_post = "\n";
				break;
			// case 'em': // em - is used to indicate emphasis.
			// case 'embed': // deprecated
			// case 'fieldset': // adds structure to forms by grouping together related controls and labels.
			// case 'font': // deprecated
			// case 'form': // is used to create data entry forms.
			// @todo Check Action && Method
			case 'h1':
				$node_text.= "\n# ";
				$node_post = "#\n";
				break;
			case 'h2':
				$node_text.= "\n## ";
				$node_post = "##\n";
				break;
			case 'h3':
				$node_text.= "\n### ";
				$node_post = "###\n";
				break;
			case 'h4':
				$node_text.= "\n#### ";
				$node_post = "####\n";
				break;
			case 'h5':
				$node_text.= "\n##### ";
				$node_post = "#####\n";
				break;
			case 'h6':
				$node_text.= "\n###### ";
				$node_post = "######\n";
				break;
			case 'hr': // used to separate sections of content
				$node_text.= sprintf("\n%s\n", str_repeat('-',72) );
				break;
			// case 'img':
			// case 'meta':
			// case 'input': // a multi-purpose form control
			// case 'ins': // used to mark up content that has been inserted into the current version of a document
			// case 'kbd': // indicates input to be entered by the user.
			// case 'label': // associates a label with form controls such as input, textarea, select and object.
			// case 'legend': // caption to a fieldset element.
			case 'li': // represents a list item in ordered lists and unordered lists
				$node_text.= '  -';
				$node_post = "\n";
				break;
			// case 'link': // conveys relationship information that can be used by Web browsers and search engines
			// case 'map': specifies a client-side image map that may be referenced by elements such as img, select and object.
			// case 'meta':
			// case 'noscript': // allows authors to provide alternate content when a script is not executed.
			// case 'object': // provides a generic way of embedding objects such as images, movies and applications (Java applets, browser plug-ins, etc.) into Web pages.
			case 'ol': // used to create ordered lists
				$node_text.= "\n";
				$node_post = "\n";
				break;
			// case 'optgroup': // used to group the choices offered in select form controls
			// case 'option': // represents a choice offered by select form controls.
			case 'p':
				$node_text.= "\n";
				$node_post = "\n";
				break;
			// case 'param':
			case 'pre':
				$node_text.= "\n";
				$node_post = "\n";
				break;
			// case 'q':
			// case 'rb':
			// case 'rbc':
			// case 'rp':
			// case 'rt':
			// case 'rtc':
			// case 'ruby':
			// case 's': // deprecated
			// case 'samp':
			// case 'script':
			// case 'select':
			// case 'shadow':
			// case 'small':
			// case 'span':
			// case 'strike':
			// case 'strong':
			// case 'style':
			// case 'sub':
			// case 'sup':
			case 'table':
				$node_text.= sprintf("\n%s\n", str_repeat('-',72) );
				$node_post = sprintf("\n%s\n", str_repeat('-',72) );
				break;
			// case 'tbody':
			// case 'td':
			// case 'textarea':
			// case 'tfoot':
			// case 'th':
			// case 'thead':
			case 'title':
				// Remove Title
				$cn->removeChild( $cn->firstChild );
				break;
			case 'tr':
				$node_text.= "\n";
				$node_post = "\n";
				break;
			// case 'tt':
			case 'u': // deprecated
				$node_text.= '_';
				$node_post = '_ ';
				break;
			case 'ul':
				// $node_text.= "\n";
				$node_post = "\n";
				break;
			// case 'var':
			// case 'isindex':
			// case 'layer':
			// case 'menu':
			// case 'noembed':
			// Default Handler!
			default:
				if ($cn->nodeType == XML_TEXT_NODE) {
					$x = trim(html_entity_decode($cn->nodeValue));
					if (!empty($x)) {
						$node_text.= $x;
					}
					$node_text.= ' ';
				}
			}

			// Sub-Routine to Check Children Elements
			if ($cn->nodeType == XML_ELEMENT_NODE) {
				$node_text.= self::_html2text_node($cn);
				if (strlen($node_post)) {
					$node_text.= $node_post;
					$node_post = null;
				}
			}


		}
		// Close an Open Node
		//if (count($this->_node_post)) {
		//	$this->_text.= array_pop($this->_node_post);
		//}
		//if (count($this->_node_open)) {
		//  $this->_page_dump.= sprintf('</%s>',array_pop($this->_node_open));
		//}
		// Back out and up!
		//return ($dump . "\n");
		return $node_text;
	}

	/**
	*/
	private static function _attr_html($attr)
	{
		ksort($attr);
		$buf = array();
		foreach ($attr as $k=>$v) {
			$buf[] = sprintf('%s="%s"',$k,htmlspecialchars($v,ENT_QUOTES));
		}
		return implode(' ',$buf);
	}

	/**
	*/
	private static function _attr_init($name,$attr,$args=null)
	{
		if (!is_array($attr)) {
			$attr = array();
		}
		if (!is_array($args)) {
			$args = array();
		}
		$ret = array_merge($attr,$args);
		if (empty($ret['id'])) {
			$ret['id'] = $name;
		}
		if (empty($ret['name'])) {
			$ret['name'] = $name;
		}
		return $ret;
	}

}