joshhartman · April 14, 2013 02:27 · Apr 14, 2013
diff --git a/autop.php b/autop.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * Replaces double line-breaks with paragraph elements.
+ *
+ * A group of regex replaces used to identify text formatted with newlines and
+ * replace double line-breaks with HTML paragraph tags. The remaining
+ * line-breaks after conversion become <<br />> tags, unless $br is set to '0'
+ * or 'false'.
+ *
+ * @param string $pee The text which has to be formatted.
+ * @param bool $br Optional. If set, this will convert all remaining line-breaks after paragraphing. Default true.
+ * @return string Text which has been converted into correct paragraph tags.
+ */
+function autop($pee, $br = true) {
+  $pre_tags = array();
+
+	if ( trim($pee) === '' )
+		return '';
+
+	$pee = $pee . "\n"; // just to make things a little easier, pad the end
+
+	if ( strpos($pee, '<pre') !== false ) {
+		$pee_parts = explode( '</pre>', $pee );
+		$last_pee = array_pop($pee_parts);
+		$pee = '';
+		$i = 0;
+
+		foreach ( $pee_parts as $pee_part ) {
+			$start = strpos($pee_part, '<pre');
+
+			// Malformed html?
+			if ( $start === false ) {
+				$pee .= $pee_part;
+				continue;
+			}
+
+			$name = "<pre wp-pre-tag-$i></pre>";
+			$pre_tags[$name] = substr( $pee_part, $start ) . '</pre>';
+
+			$pee .= substr( $pee_part, 0, $start ) . $name;
+			$i++;
+		}
+
+		$pee .= $last_pee;
+	}
+
+	$pee = preg_replace('|<br />\s*<br />|', "\n\n", $pee);
+	// Space things out a little
+	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|select|option|form|map|area|blockquote|address|math|style|p|h[1-6]|hr|fieldset|noscript|samp|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
+	$pee = preg_replace('!(<' . $allblocks . '[^>]*>)!', "\n$1", $pee);
+	$pee = preg_replace('!(</' . $allblocks . '>)!', "$1\n\n", $pee);
+	$pee = str_replace(array("\r\n", "\r"), "\n", $pee); // cross-platform newlines
+	if ( strpos($pee, '<object') !== false ) {
+		$pee = preg_replace('|\s*<param([^>]*)>\s*|', "<param$1>", $pee); // no pee inside object/embed
+		$pee = preg_replace('|\s*</embed>\s*|', '</embed>', $pee);
+	}
+	$pee = preg_replace("/\n\n+/", "\n\n", $pee); // take care of duplicates
+	// make paragraphs, including one at the end
+	$pees = preg_split('/\n\s*\n/', $pee, -1, PREG_SPLIT_NO_EMPTY);
+	$pee = '';
+	foreach ( $pees as $tinkle )
+		$pee .= '<p>' . trim($tinkle, "\n") . "</p>\n";
+	$pee = preg_replace('|<p>\s*</p>|', '', $pee); // under certain strange conditions it could create a P of entirely whitespace
+	$pee = preg_replace('!<p>([^<]+)</(div|address|form)>!', "<p>$1</p></$2>", $pee);
+	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); // don't pee all over a tag
+	$pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); // problem with nested lists
+	$pee = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $pee);
+	$pee = str_replace('</blockquote></p>', '</p></blockquote>', $pee);
+	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)!', "$1", $pee);
+	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee);
+	if ( $br ) {
+		$pee = preg_replace_callback('/<(script|style).*?<\/\\1>/s', create_function('$matches', 'return str_replace("\n", "<PreserveNewline />", $matches[0]);'), $pee);
+		$pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee); // optionally make line breaks
+		$pee = str_replace('<PreserveNewline />', "\n", $pee);
+	}
+	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*<br />!', "$1", $pee);
+	$pee = preg_replace('!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $pee);
+	$pee = preg_replace( "|\n</p>$|", '</p>', $pee );
+
+	if ( !empty($pre_tags) )
+		$pee = str_replace(array_keys($pre_tags), array_values($pre_tags), $pee);
+
+	return $pee;
+}