From b6c120104f520e753c8ef8331f4ede822f658539 Mon Sep 17 00:00:00 2001 From: moodler Date: Fri, 7 Nov 2003 03:25:09 +0000 Subject: [PATCH] A new function for converting HTML into text form --- lib/html2text.php | 162 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 lib/html2text.php diff --git a/lib/html2text.php b/lib/html2text.php new file mode 100644 index 0000000000..f96108f015 --- /dev/null +++ b/lib/html2text.php @@ -0,0 +1,162 @@ +, +Closing or tags without their corresponding opening tags, +Tags within tags, which will be rendered, even though they +should not be. + +Conversion requires a lot of preg_replace statements, so it can be quite slow with +large HTML files. + +****** +To use +****** + +This library requires PHP 4+ + +To use this library, put the following line in your script before the part that needs it: +require('PATH_TO_THIS_FILE/html2text.php'); + +To convert HTML/PHP to text: + $textVersion = html2text( $HTMLversion ); + +************ +Further info +************ + +For the technically minded, this is the process I use for converting HTML to approx text: + +REMOVE php start and end tags +REMOVE +ensure HTML uses entities in the right places (like inside tags) so strip_tags works properly + +carefully remove everything between them +strip_tags except the important ones +replace all \s that are after the start or a and before 
 or end with a single space
+
+\n          --------------------
+
+\n\n
+
+^
+(TH|TD)>
+\n
+
  • 
+\n· 
+
    
+\n\t
+
+\t
+
+[LINK:hrefWithout#]
+
+[IMG:alt]
+
    
+[FORM:action]
+
+[INPUT]
+strip tags again, leaving nothing this time
+un-htmlspecialchars
+word wrap (this will also affect pre, but as this is intended for email use, I don't care)
+
+
+*/
+
+function html2text( $badStr ) {
+	//remove PHP if it exists
+	if( $andPHP ) { while( substr_count( $badStr, '<'.'?' ) && substr_count( $badStr, '?'.'>' ) && strpos( $badStr, '?'.'>' ) > strpos( $badStr, '<'.'?' ) ) {
+		$badStr = substr( $badStr, 0, strpos( $badStr, '<'.'?' ) ) . substr( $badStr, strpos( $badStr, '?'.'>' ) + 2 ); } }
+	//remove comments
+	while( substr_count( $badStr, '' ) && strpos( $badStr, '-->' ) > strpos( $badStr, '' ) + 3 ); }
+	//now make sure all HTML tags are correctly written (> not in between quotes)
+	for( $x = 0, $goodStr = '', $is_open_tb = false, $is_open_sq = false, $is_open_sq = false; strlen( $chr = $badStr{$x} ); $x++ ) {
+		//take each letter in turn and check if that character is permitted there
+		switch( $chr ) {
+			case '<':
+				if( !$is_open_tb && strtolower( substr( $badStr, $x + 1, 5 ) ) == 'style' ) {
+					$badStr = substr( $badStr, 0, $x ) . substr( $badStr, strpos( strtolower( $badStr ), '' ) + 7 ); $chr = '';
+				} elseif( !$is_open_tb && strtolower( substr( $badStr, $x + 1, 6 ) ) == 'script' ) {
+					$badStr = substr( $badStr, 0, $x ) . substr( $badStr, strpos( strtolower( $badStr ), '' ) + 8 ); $chr = '';
+				} elseif( !$is_open_tb ) { $is_open_tb = true; } else { $chr = '<'; }
+				break;
+			case '>':
+				if( !$is_open_tb || $is_open_dq || $is_open_sq ) { $chr = '>'; } else { $is_open_tb = false; }
+				break;
+			case '"':
+				if( $is_open_tb && !$is_open_dq && !$is_open_sq ) { $is_open_dq = true; }
+				elseif( $is_open_tb && $is_open_dq && !$is_open_sq ) { $is_open_dq = false; }
+				else { $chr = '"'; }
+				break;
+			case "'":
+				if( $is_open_tb && !$is_open_dq && !$is_open_sq ) { $is_open_sq = true; }
+				elseif( $is_open_tb && !$is_open_dq && $is_open_sq ) { $is_open_sq = false; }
+		} $goodStr .= $chr;
+	}
+	//now that the page is valid (I hope) for strip_tags, strip all unwanted tags
+	$goodStr = strip_tags( $goodStr, '<hr><h1><h2><h3><h4><h5><h6><div><p><pre><sup><ul><ol><br><dl><dt><table><caption><tr><li><dd><th><td><a><area><img><form><input><textarea><button><select><option>' );
+	//strip extra whitespace except between <pre> and <textarea> tags
+	$badStr = preg_split( "/<\/?pre[^>]*>/i", $goodStr );
+	for( $x = 0; is_string( $badStr[$x] ); $x++ ) {
+		if( $x % 2 ) { $badStr[$x] = '<pre>'.$badStr[$x].'</pre>'; } else {
+			$goodStr = preg_split( "/<\/?textarea[^>]*>/i", $badStr[$x] );
+			for( $z = 0; is_string( $goodStr[$z] ); $z++ ) {
+				if( $z % 2 ) { $goodStr[$z] = '<textarea>'.$goodStr[$z].'</textarea>'; } else {
+					$goodStr[$z] = preg_replace( "/\s+/", ' ', $goodStr[$z] );
+			} }
+			$badStr[$x] = implode('',$goodStr);
+	} }
+	$goodStr = implode('',$badStr);
+	//remove all options from select inputs
+	$goodStr = preg_replace( "/<option[^>]*>[^<]*/i", '', $goodStr );
+	//replace all tags with their text equivalents
+	$goodStr = preg_replace( "/<(\/title|hr)[^>]*>/i", "\n          --------------------\n", $goodStr );
+	$goodStr = preg_replace( "/<(h|div|p)[^>]*>/i", "\n\n", $goodStr );
+	$goodStr = preg_replace( "/<sup[^>]*>/i", '^', $goodStr );
+	$goodStr = preg_replace( "/<(ul|ol|br|dl|dt|table|caption|\/textarea|tr[^>]*>\s*<(td|th))[^>]*>/i", "\n", $goodStr );
+	$goodStr = preg_replace( "/<li[^>]*>/i", "\n· ", $goodStr );
+	$goodStr = preg_replace( "/<dd[^>]*>/i", "\n\t", $goodStr );
+	$goodStr = preg_replace( "/<(th|td)[^>]*>/i", "\t", $goodStr );
+	///$goodStr = preg_replace( "/<a[^>]* href=(\"((?!\"|#|javascript:)[^\"#]*)(\"|#)|'((?!'|#|javascript:)[^'#]*)('|#)|((?!'|\"|>|#|javascript:)[^#\"'> ]*))[^>]*>/i", "[LINK: $2$4$6] ", $goodStr ); /// Moodle
+	$goodStr = preg_replace( "/<a[^>]* href=(\"((?!\"|#|javascript:)[^\"#]*)(\"|#)|'((?!'|#|javascript:)[^'#]*)('|#)|((?!'|\"|>|#|javascript:)[^#\"'> ]*))[^>]*>/i", "[$2$4$6] ", $goodStr );
+	/// $goodStr = preg_replace( "/<img[^>]* alt=(\"([^\"]+)\"|'([^']+)'|([^\"'> ]+))[^>]*>/i", "[IMAGE: $2$3$4] ", $goodStr );/// Moodle
+	$goodStr = preg_replace( "/<img[^>]* alt=(\"([^\"]+)\"|'([^']+)'|([^\"'> ]+))[^>]*>/i", "{$2$3$4} ", $goodStr );
+	$goodStr = preg_replace( "/<form[^>]* action=(\"([^\"]+)\"|'([^']+)'|([^\"'> ]+))[^>]*>/i", "\n[FORM: $2$3$4] ", $goodStr );
+	$goodStr = preg_replace( "/<(input|textarea|button|select)[^>]*>/i", "[INPUT] ", $goodStr );
+	//strip all remaining tags (mostly closing tags)
+	$goodStr = strip_tags( $goodStr );
+	//convert HTML entities
+	$goodStr = strtr( $goodStr, array_flip( get_html_translation_table( HTML_ENTITIES ) ) );
+	preg_replace( "/&#(\d+);/me", "chr('$1')", $goodStr );
+	//wordwrap
+	///$goodStr = wordwrap($goodStr);    /// Moodle
+	$goodStr = wordwrap($goodStr, 70);
+	//make sure there are no more than 3 linebreaks in a row and trim whitespace
+	return preg_replace( "/^\n*|\n*$/", '', preg_replace( "/[ \t]+(\n|$)/", "$1", preg_replace( "/\n(\s*\n){2}/", "\n\n\n", preg_replace( "/\r\n?|\f/", "\n", str_replace( chr(160), ' ', $goodStr ) ) ) ) );
+}
+
+?>
-- 
2.39.5