diff options
Diffstat (limited to 'system/libraries/Typography.php')
| -rw-r--r-- | system/libraries/Typography.php | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/system/libraries/Typography.php b/system/libraries/Typography.php new file mode 100644 index 000000000..242ca3cb6 --- /dev/null +++ b/system/libraries/Typography.php @@ -0,0 +1,406 @@ +<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +/** + * CodeIgniter + * + * An open source application development framework for PHP 4.3.2 or newer + * + * @package CodeIgniter + * @author ExpressionEngine Dev Team + * @copyright Copyright (c) 2008 - 2009, EllisLab, Inc. + * @license http://codeigniter.com/user_guide/license.html + * @link http://codeigniter.com + * @since Version 1.0 + * @filesource + */ + +// ------------------------------------------------------------------------ + +/** + * Typography Class + * + * + * @access private + * @category Helpers + * @author ExpressionEngine Dev Team + * @link http://codeigniter.com/user_guide/helpers/ + */ +class CI_Typography { + + // Block level elements that should not be wrapped inside <p> tags + var $block_elements = 'address|blockquote|div|dl|fieldset|form|h\d|hr|noscript|object|ol|p|pre|script|table|ul'; + + // Elements that should not have <p> and <br /> tags within them. + var $skip_elements = 'p|pre|ol|ul|dl|object|table|h\d'; + + // Tags we want the parser to completely ignore when splitting the string. + var $inline_elements = 'a|abbr|acronym|b|bdo|big|br|button|cite|code|del|dfn|em|i|img|ins|input|label|map|kbd|q|samp|select|small|span|strong|sub|sup|textarea|tt|var'; + + // array of block level elements that require inner content to be within another block level element + var $inner_block_required = array('blockquote'); + + // the last block element parsed + var $last_block_element = ''; + + // whether or not to protect quotes within { curly braces } + var $protect_braced_quotes = FALSE; + + /** + * Nothing to do here... + * + */ + function CI_Typography() + { + } + + /** + * Auto Typography + * + * This function converts text, making it typographically correct: + * - Converts double spaces into paragraphs. + * - Converts single line breaks into <br /> tags + * - Converts single and double quotes into correctly facing curly quote entities. + * - Converts three dots into ellipsis. + * - Converts double dashes into em-dashes. + * - Converts two spaces into entities + * + * @access public + * @param string + * @param bool whether to reduce more then two consecutive newlines to two + * @return string + */ + function auto_typography($str, $reduce_linebreaks = FALSE) + { + if ($str == '') + { + return ''; + } + + // Standardize Newlines to make matching easier + if (strpos($str, "\r") !== FALSE) + { + $str = str_replace(array("\r\n", "\r"), "\n", $str); + } + + // Reduce line breaks. If there are more than two consecutive linebreaks + // we'll compress them down to a maximum of two since there's no benefit to more. + if ($reduce_linebreaks === TRUE) + { + $str = preg_replace("/\n\n+/", "\n\n", $str); + } + + // HTML comment tags don't conform to patterns of normal tags, so pull them out separately, only if needed + $html_comments = array(); + if (strpos($str, '<!--') !== FALSE) + { + if (preg_match_all("#(<!\-\-.*?\-\->)#s", $str, $matches)) + { + for ($i = 0, $total = count($matches[0]); $i < $total; $i++) + { + $html_comments[] = $matches[0][$i]; + $str = str_replace($matches[0][$i], '{@HC'.$i.'}', $str); + } + } + } + + // match and yank <pre> tags if they exist. It's cheaper to do this separately since most content will + // not contain <pre> tags, and it keeps the PCRE patterns below simpler and faster + if (strpos($str, '<pre') !== FALSE) + { + $str = preg_replace_callback("#<pre.*?>.*?</pre>#si", array($this, '_protect_characters'), $str); + } + + // Convert quotes within tags to temporary markers. + $str = preg_replace_callback("#<.+?>#si", array($this, '_protect_characters'), $str); + + // Do the same with braces if necessary + if ($this->protect_braced_quotes === TRUE) + { + $str = preg_replace_callback("#\{.+?\}#si", array($this, '_protect_characters'), $str); + } + + // Convert "ignore" tags to temporary marker. The parser splits out the string at every tag + // it encounters. Certain inline tags, like image tags, links, span tags, etc. will be + // adversely affected if they are split out so we'll convert the opening bracket < temporarily to: {@TAG} + $str = preg_replace("#<(/*)(".$this->inline_elements.")([ >])#i", "{@TAG}\\1\\2\\3", $str); + + // Split the string at every tag. This expression creates an array with this prototype: + // + // [array] + // { + // [0] = <opening tag> + // [1] = Content... + // [2] = <closing tag> + // Etc... + // } + $chunks = preg_split('/(<(?:[^<>]+(?:"[^"]*"|\'[^\']*\')?)+>)/', $str, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY); + + // Build our finalized string. We cycle through the array, skipping tags, and processing the contained text + $str = ''; + $process = TRUE; + $paragraph = FALSE; + $current_chunk = 0; + $total_chunks = count($chunks); + + foreach ($chunks as $chunk) + { + $current_chunk++; + + // Are we dealing with a tag? If so, we'll skip the processing for this cycle. + // Well also set the "process" flag which allows us to skip <pre> tags and a few other things. + if (preg_match("#<(/*)(".$this->block_elements.").*?>#", $chunk, $match)) + { + if (preg_match("#".$this->skip_elements."#", $match[2])) + { + $process = ($match[1] == '/') ? TRUE : FALSE; + } + + if ($match[1] == '') + { + $this->last_block_element = $match[2]; + } + + $str .= $chunk; + continue; + } + + if ($process == FALSE) + { + $str .= $chunk; + continue; + } + + // Force a newline to make sure end tags get processed by _format_newlines() + if ($current_chunk == $total_chunks) + { + $chunk .= "\n"; + } + + // Convert Newlines into <p> and <br /> tags + $str .= $this->_format_newlines($chunk); + } + + // No opening block level tag? Add it if needed. + if ( ! preg_match("/^\s*<(?:".$this->block_elements.")/i", $str)) + { + $str = preg_replace("/^(.*?)<(".$this->block_elements.")/i", '<p>$1</p><$2', $str); + } + + // Convert quotes, elipsis, em-dashes, non-breaking spaces, and ampersands + $str = $this->format_characters($str); + + // restore HTML comments + for ($i = 0, $total = count($html_comments); $i < $total; $i++) + { + // remove surrounding paragraph tags, but only if there's an opening paragraph tag + // otherwise HTML comments at the ends of paragraphs will have the closing tag removed + // if '<p>{@HC1}' then replace <p>{@HC1}</p> with the comment, else replace only {@HC1} with the comment + $str = preg_replace('#(?(?=<p>\{@HC'.$i.'\})<p>\{@HC'.$i.'\}(\s*</p>)|\{@HC'.$i.'\})#s', $html_comments[$i], $str); + } + + // Final clean up + $table = array( + + // If the user submitted their own paragraph tags within the text + // we will retain them instead of using our tags. + '/(<p[^>*?]>)<p>/' => '$1', // <?php BBEdit syntax coloring bug fix + + // Reduce multiple instances of opening/closing paragraph tags to a single one + '#(</p>)+#' => '</p>', + '/(<p>\W*<p>)+/' => '<p>', + + // Clean up stray paragraph tags that appear before block level elements + '#<p></p><('.$this->block_elements.')#' => '<$1', + + // Clean up stray non-breaking spaces preceeding block elements + '#( \s*)+<('.$this->block_elements.')#' => ' <$2', + + // Replace the temporary markers we added earlier + '/\{@TAG\}/' => '<', + '/\{@DQ\}/' => '"', + '/\{@SQ\}/' => "'", + '/\{@DD\}/' => '--', + '/\{@NBS\}/' => ' ' + + ); + + // Do we need to reduce empty lines? + if ($reduce_linebreaks === TRUE) + { + $table['#<p>\n*</p>#'] = ''; + } + else + { + // If we have empty paragraph tags we add a non-breaking space + // otherwise most browsers won't treat them as true paragraphs + $table['#<p></p>#'] = '<p> </p>'; + } + + return preg_replace(array_keys($table), $table, $str); + + } + + // -------------------------------------------------------------------- + + /** + * Format Characters + * + * This function mainly converts double and single quotes + * to curly entities, but it also converts em-dashes, + * double spaces, and ampersands + * + * @access public + * @param string + * @return string + */ + function format_characters($str) + { + static $table; + + if ( ! isset($table)) + { + $table = array( + // nested smart quotes, opening and closing + // note that rules for grammar (English) allow only for two levels deep + // and that single quotes are _supposed_ to always be on the outside + // but we'll accommodate both + // Note that in all cases, whitespace is the primary determining factor + // on which direction to curl, with non-word characters like punctuation + // being a secondary factor only after whitespace is addressed. + '/\'"(\s|$)/' => '’”$1', + '/(^|\s|<p>)\'"/' => '$1‘“', + '/\'"(\W)/' => '’”$1', + '/(\W)\'"/' => '$1‘“', + '/"\'(\s|$)/' => '”’$1', + '/(^|\s|<p>)"\'/' => '$1“‘', + '/"\'(\W)/' => '”’$1', + '/(\W)"\'/' => '$1“‘', + + // single quote smart quotes + '/\'(\s|$)/' => '’$1', + '/(^|\s|<p>)\'/' => '$1‘', + '/\'(\W)/' => '’$1', + '/(\W)\'/' => '$1‘', + + // double quote smart quotes + '/"(\s|$)/' => '”$1', + '/(^|\s|<p>)"/' => '$1“', + '/"(\W)/' => '”$1', + '/(\W)"/' => '$1“', + + // apostrophes + "/(\w)'(\w)/" => '$1’$2', + + // Em dash and ellipses dots + '/\s?\-\-\s?/' => '—', + '/(\w)\.{3}/' => '$1…', + + // double space after sentences + '/(\W) /' => '$1 ', + + // ampersands, if not a character entity + '/&(?!#?[a-zA-Z0-9]{2,};)/' => '&' + ); + } + + return preg_replace(array_keys($table), $table, $str); + } + + // -------------------------------------------------------------------- + + /** + * Format Newlines + * + * Converts newline characters into either <p> tags or <br /> + * + * @access public + * @param string + * @return string + */ + function _format_newlines($str) + { + if ($str == '') + { + return $str; + } + + if (strpos($str, "\n") === FALSE && ! in_array($this->last_block_element, $this->inner_block_required)) + { + return $str; + } + + // Convert two consecutive newlines to paragraphs + $str = str_replace("\n\n", "</p>\n\n<p>", $str); + + // Convert single spaces to <br /> tags + $str = preg_replace("/([^\n])(\n)([^\n])/", "\\1<br />\\2\\3", $str); + + // Wrap the whole enchilada in enclosing paragraphs + if ($str != "\n") + { + $str = '<p>'.$str.'</p>'; + } + + // Remove empty paragraphs if they are on the first line, as this + // is a potential unintended consequence of the previous code + $str = preg_replace("/<p><\/p>(.*)/", "\\1", $str, 1); + + return $str; + } + + // ------------------------------------------------------------------------ + + /** + * Protect Characters + * + * Protects special characters from being formatted later + * We don't want quotes converted within tags so we'll temporarily convert them to {@DQ} and {@SQ} + * and we don't want double dashes converted to emdash entities, so they are marked with {@DD} + * likewise double spaces are converted to {@NBS} to prevent entity conversion + * + * @access public + * @param array + * @return string + */ + function _protect_characters($match) + { + return str_replace(array("'",'"','--',' '), array('{@SQ}', '{@DQ}', '{@DD}', '{@NBS}'), $match[0]); + } + + // -------------------------------------------------------------------- + + /** + * Convert newlines to HTML line breaks except within PRE tags + * + * @access public + * @param string + * @return string + */ + function nl2br_except_pre($str) + { + $ex = explode("pre>",$str); + $ct = count($ex); + + $newstr = ""; + for ($i = 0; $i < $ct; $i++) + { + if (($i % 2) == 0) + { + $newstr .= nl2br($ex[$i]); + } + else + { + $newstr .= $ex[$i]; + } + + if ($ct - 1 != $i) + $newstr .= "pre>"; + } + + return $newstr; + } + +} +// END Typography Class + +/* End of file Typography.php */ +/* Location: ./system/libraries/Typography.php */
\ No newline at end of file |