509 lines
16 KiB
PHP
509 lines
16 KiB
PHP
<?php
|
|
|
|
class NewsletterProHtml2Text
|
|
{
|
|
public static function defaultOptions()
|
|
{
|
|
return array(
|
|
'ignore_errors' => false,
|
|
'drop_links' => false,
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Tries to convert the given HTML into a plain text format - best suited for
|
|
* e-mail display, etc.
|
|
*
|
|
* <p>In particular, it tries to maintain the following features:
|
|
* <ul>
|
|
* <li>Links are maintained, with the 'href' copied over
|
|
* <li>Information in the <head> is lost
|
|
* </ul>
|
|
*
|
|
* @param string $html the input HTML
|
|
* @param boolean $ignore_error Ignore xml parsing errors
|
|
* @return string the HTML converted, as best as possible, to text
|
|
* @throws NewsletterProHtml2TextException if the HTML could not be loaded as a {@link \DOMDocument}
|
|
*/
|
|
public static function convert($html, $options = array())
|
|
{
|
|
if ($options === false || $options === true) {
|
|
// Using old style (< 1.0) of passing in options
|
|
$options = array('ignore_errors' => $options);
|
|
}
|
|
|
|
$options = array_merge(static::defaultOptions(), $options);
|
|
|
|
// check all options are valid
|
|
foreach ($options as $key => $value) {
|
|
if (!in_array($key, array_keys(static::defaultOptions()))) {
|
|
throw new \InvalidArgumentException("Unknown html2text option '$key'");
|
|
}
|
|
}
|
|
|
|
$is_office_document = static::isOfficeDocument($html);
|
|
|
|
if ($is_office_document) {
|
|
// remove office namespace
|
|
$html = str_replace(array("<o:p>", "</o:p>"), "", $html);
|
|
}
|
|
|
|
$html = static::fixNewlines($html);
|
|
if (mb_detect_encoding($html, "UTF-8", true)) {
|
|
$html = mb_convert_encoding($html, "HTML-ENTITIES", "UTF-8");
|
|
}
|
|
|
|
$doc = static::getDocument($html, $options['ignore_errors']);
|
|
|
|
$output = static::iterateOverNode($doc, null, false, $is_office_document, $options);
|
|
|
|
// process output for whitespace/newlines
|
|
$output = static::processWhitespaceNewlines($output);
|
|
|
|
return $output;
|
|
}
|
|
|
|
/**
|
|
* Unify newlines; in particular, \r\n becomes \n, and
|
|
* then \r becomes \n. This means that all newlines (Unix, Windows, Mac)
|
|
* all become \ns.
|
|
*
|
|
* @param string $text text with any number of \r, \r\n and \n combinations
|
|
* @return string the fixed text
|
|
*/
|
|
public static function fixNewlines($text)
|
|
{
|
|
// replace \r\n to \n
|
|
$text = str_replace("\r\n", "\n", $text);
|
|
// remove \rs
|
|
$text = str_replace("\r", "\n", $text);
|
|
|
|
return $text;
|
|
}
|
|
|
|
public static function nbspCodes()
|
|
{
|
|
return array(
|
|
"\xc2\xa0",
|
|
"\u00a0",
|
|
);
|
|
}
|
|
|
|
public static function zwnjCodes()
|
|
{
|
|
return array(
|
|
"\xe2\x80\x8c",
|
|
"\u200c",
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Remove leading or trailing spaces and excess empty lines from provided multiline text
|
|
*
|
|
* @param string $text multiline text any number of leading or trailing spaces or excess lines
|
|
* @return string the fixed text
|
|
*/
|
|
public static function processWhitespaceNewlines($text)
|
|
{
|
|
|
|
// remove excess spaces around tabs
|
|
$text = preg_replace("/ *\t */im", "\t", $text);
|
|
|
|
// remove leading whitespace
|
|
$text = ltrim($text);
|
|
|
|
// remove leading spaces on each line
|
|
$text = preg_replace("/\n[ \t]*/im", "\n", $text);
|
|
|
|
// convert non-breaking spaces to regular spaces to prevent output issues,
|
|
// do it here so they do NOT get removed with other leading spaces, as they
|
|
// are sometimes used for indentation
|
|
$text = static::renderText($text);
|
|
|
|
// remove trailing whitespace
|
|
$text = rtrim($text);
|
|
|
|
// remove trailing spaces on each line
|
|
$text = preg_replace("/[ \t]*\n/im", "\n", $text);
|
|
|
|
// unarmor pre blocks
|
|
$text = static::fixNewLines($text);
|
|
|
|
// remove unnecessary empty lines
|
|
$text = preg_replace("/\n\n\n*/im", "\n\n", $text);
|
|
|
|
return $text;
|
|
}
|
|
|
|
/**
|
|
* Parse HTML into a DOMDocument
|
|
*
|
|
* @param string $html the input HTML
|
|
* @param boolean $ignore_error Ignore xml parsing errors
|
|
* @return \DOMDocument the parsed document tree
|
|
*/
|
|
public static function getDocument($html, $ignore_error = false)
|
|
{
|
|
$doc = new \DOMDocument();
|
|
|
|
$html = trim($html);
|
|
|
|
if (!$html) {
|
|
// DOMDocument doesn't support empty value and throws an error
|
|
// Return empty document instead
|
|
return $doc;
|
|
}
|
|
|
|
if ($html[0] !== '<') {
|
|
// If HTML does not begin with a tag, we put a body tag around it.
|
|
// If we do not do this, PHP will insert a paragraph tag around
|
|
// the first block of text for some reason which can mess up
|
|
// the newlines. See pre.html test for an example.
|
|
$html = '<body>' . $html . '</body>';
|
|
}
|
|
|
|
if ($ignore_error) {
|
|
$doc->strictErrorChecking = false;
|
|
$doc->recover = true;
|
|
$doc->xmlStandalone = true;
|
|
$old_internal_errors = libxml_use_internal_errors(true);
|
|
$load_result = $doc->loadHTML($html, LIBXML_NOWARNING | LIBXML_NOERROR | LIBXML_NONET | LIBXML_PARSEHUGE);
|
|
libxml_use_internal_errors($old_internal_errors);
|
|
} else {
|
|
$load_result = $doc->loadHTML($html);
|
|
}
|
|
|
|
if (!$load_result) {
|
|
throw new NewsletterProHtml2TextException("Could not load HTML - badly formed?", $html);
|
|
}
|
|
|
|
return $doc;
|
|
}
|
|
|
|
/**
|
|
* Can we guess that this HTML is generated by Microsoft Office?
|
|
*/
|
|
public static function isOfficeDocument($html)
|
|
{
|
|
return strpos($html, "urn:schemas-microsoft-com:office") !== false;
|
|
}
|
|
|
|
/**
|
|
* Replace any special characters with simple text versions, to prevent output issues:
|
|
* - Convert non-breaking spaces to regular spaces; and
|
|
* - Convert zero-width non-joiners to '' (nothing).
|
|
*
|
|
* This is to match our goal of rendering documents as they would be rendered
|
|
* by a browser.
|
|
*/
|
|
public static function renderText($text)
|
|
{
|
|
$text = str_replace(static::nbspCodes(), " ", $text);
|
|
$text = str_replace(static::zwnjCodes(), "", $text);
|
|
return $text;
|
|
}
|
|
|
|
public static function isWhitespace($text)
|
|
{
|
|
return strlen(trim(static::renderText($text), "\n\r\t ")) === 0;
|
|
}
|
|
|
|
public static function nextChildName($node)
|
|
{
|
|
// get the next child
|
|
$nextNode = $node->nextSibling;
|
|
while ($nextNode != null) {
|
|
if ($nextNode instanceof \DOMText) {
|
|
if (!static::isWhitespace($nextNode->wholeText)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if ($nextNode instanceof \DOMElement) {
|
|
break;
|
|
}
|
|
|
|
$nextNode = $nextNode->nextSibling;
|
|
}
|
|
|
|
$nextName = null;
|
|
if (($nextNode instanceof \DOMElement || $nextNode instanceof \DOMText) && $nextNode != null) {
|
|
$nextName = strtolower($nextNode->nodeName);
|
|
}
|
|
|
|
return $nextName;
|
|
}
|
|
|
|
public static function iterateOverNode($node, $prevName = null, $in_pre = false, $is_office_document = false, $options)
|
|
{
|
|
if ($node instanceof \DOMText) {
|
|
// Replace whitespace characters with a space (equivilant to \s)
|
|
if ($in_pre) {
|
|
$text = "\n" . trim(static::renderText($node->wholeText), "\n\r\t ") . "\n";
|
|
|
|
// Remove trailing whitespace only
|
|
$text = preg_replace("/[ \t]*\n/im", "\n", $text);
|
|
|
|
// armor newlines with \r.
|
|
return str_replace("\n", "\r", $text);
|
|
} else {
|
|
$text = static::renderText($node->wholeText);
|
|
$text = preg_replace("/[\\t\\n\\f\\r ]+/im", " ", $text);
|
|
|
|
if (!static::isWhitespace($text) && ($prevName == 'p' || $prevName == 'div')) {
|
|
return "\n" . $text;
|
|
}
|
|
return $text;
|
|
}
|
|
}
|
|
|
|
if ($node instanceof \DOMDocumentType || $node instanceof \DOMProcessingInstruction) {
|
|
// ignore
|
|
return "";
|
|
}
|
|
|
|
$name = strtolower($node->nodeName);
|
|
$nextName = static::nextChildName($node);
|
|
|
|
// start whitespace
|
|
switch ($name) {
|
|
case "hr":
|
|
$prefix = '';
|
|
if ($prevName != null) {
|
|
$prefix = "\n";
|
|
}
|
|
return $prefix . "---------------------------------------------------------------\n";
|
|
|
|
case "style":
|
|
case "head":
|
|
case "title":
|
|
case "meta":
|
|
case "script":
|
|
// ignore these tags
|
|
return "";
|
|
|
|
case "h1":
|
|
case "h2":
|
|
case "h3":
|
|
case "h4":
|
|
case "h5":
|
|
case "h6":
|
|
case "ol":
|
|
case "ul":
|
|
case "pre":
|
|
// add two newlines
|
|
$output = "\n\n";
|
|
break;
|
|
|
|
case "td":
|
|
case "th":
|
|
// add tab char to separate table fields
|
|
$output = "\t";
|
|
break;
|
|
|
|
case "p":
|
|
// Microsoft exchange emails often include HTML which, when passed through
|
|
// html2text, results in lots of double line returns everywhere.
|
|
//
|
|
// To fix this, for any p element with a className of `MsoNormal` (the standard
|
|
// classname in any Microsoft export or outlook for a paragraph that behaves
|
|
// like a line return) we skip the first line returns and set the name to br.
|
|
if ($is_office_document && $node->getAttribute('class') == 'MsoNormal') {
|
|
$output = "";
|
|
$name = 'br';
|
|
break;
|
|
}
|
|
|
|
// add two lines
|
|
$output = "\n\n";
|
|
break;
|
|
|
|
case "tr":
|
|
// add one line
|
|
$output = "\n";
|
|
break;
|
|
|
|
case "div":
|
|
$output = "";
|
|
if ($prevName !== null) {
|
|
// add one line
|
|
$output .= "\n";
|
|
}
|
|
break;
|
|
|
|
case "li":
|
|
$output = "- ";
|
|
break;
|
|
|
|
default:
|
|
// print out contents of unknown tags
|
|
$output = "";
|
|
break;
|
|
}
|
|
|
|
// debug
|
|
//$output .= "[$name,$nextName]";
|
|
|
|
if (isset($node->childNodes)) {
|
|
$n = $node->childNodes->item(0);
|
|
$previousSiblingNames = array();
|
|
$previousSiblingName = null;
|
|
|
|
$parts = array();
|
|
$trailing_whitespace = 0;
|
|
|
|
while ($n != null) {
|
|
$text = static::iterateOverNode($n, $previousSiblingName, $in_pre || $name == 'pre', $is_office_document, $options);
|
|
|
|
// Pass current node name to next child, as previousSibling does not appear to get populated
|
|
if ($n instanceof \DOMDocumentType
|
|
|| $n instanceof \DOMProcessingInstruction
|
|
|| ($n instanceof \DOMText && static::isWhitespace($text))) {
|
|
// Keep current previousSiblingName, these are invisible
|
|
$trailing_whitespace++;
|
|
} else {
|
|
$previousSiblingName = strtolower($n->nodeName);
|
|
$previousSiblingNames[] = $previousSiblingName;
|
|
$trailing_whitespace = 0;
|
|
}
|
|
|
|
$node->removeChild($n);
|
|
$n = $node->childNodes->item(0);
|
|
|
|
$parts[] = $text;
|
|
}
|
|
|
|
// Remove trailing whitespace, important for the br check below
|
|
while ($trailing_whitespace-- > 0) {
|
|
array_pop($parts);
|
|
}
|
|
|
|
// suppress last br tag inside a node list if follows text
|
|
$last_name = array_pop($previousSiblingNames);
|
|
if ($last_name === 'br') {
|
|
$last_name = array_pop($previousSiblingNames);
|
|
if ($last_name === '#text') {
|
|
array_pop($parts);
|
|
}
|
|
}
|
|
|
|
$output .= implode('', $parts);
|
|
}
|
|
|
|
// end whitespace
|
|
switch ($name) {
|
|
case "h1":
|
|
case "h2":
|
|
case "h3":
|
|
case "h4":
|
|
case "h5":
|
|
case "h6":
|
|
case "pre":
|
|
case "p":
|
|
// add two lines
|
|
$output .= "\n\n";
|
|
break;
|
|
|
|
case "br":
|
|
// add one line
|
|
$output .= "\n";
|
|
break;
|
|
|
|
case "div":
|
|
break;
|
|
|
|
case "a":
|
|
// links are returned in [text](link) format
|
|
$href = $node->getAttribute("href");
|
|
|
|
$output = trim($output);
|
|
|
|
// remove double [[ ]] s from linking images
|
|
if (substr($output, 0, 1) == "[" && substr($output, -1) == "]") {
|
|
$output = substr($output, 1, strlen($output) - 2);
|
|
|
|
// for linking images, the title of the <a> overrides the title of the <img>
|
|
if ($node->getAttribute("title")) {
|
|
$output = $node->getAttribute("title");
|
|
}
|
|
}
|
|
|
|
// if there is no link text, but a title attr
|
|
if (!$output && $node->getAttribute("title")) {
|
|
$output = $node->getAttribute("title");
|
|
}
|
|
|
|
if ($href == null) {
|
|
// it doesn't link anywhere
|
|
if ($node->getAttribute("name") != null) {
|
|
if ($options['drop_links']) {
|
|
$output = "$output";
|
|
} else {
|
|
$output = "[$output]";
|
|
}
|
|
}
|
|
} else {
|
|
if ($href == $output || $href == "mailto:$output" || $href == "http://$output" || $href == "https://$output") {
|
|
// link to the same address: just use link
|
|
$output = "$output";
|
|
} else {
|
|
// replace it
|
|
if ($output) {
|
|
if ($options['drop_links']) {
|
|
$output = "$output";
|
|
} else {
|
|
$output = "[$output]($href)";
|
|
}
|
|
} else {
|
|
// empty string
|
|
$output = "$href";
|
|
}
|
|
}
|
|
}
|
|
|
|
// does the next node require additional whitespace?
|
|
switch ($nextName) {
|
|
case "h1": case "h2": case "h3": case "h4": case "h5": case "h6":
|
|
$output .= "\n";
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case "img":
|
|
if ($node->getAttribute("title")) {
|
|
$output = "[" . $node->getAttribute("title") . "]";
|
|
} elseif ($node->getAttribute("alt")) {
|
|
$output = "[" . $node->getAttribute("alt") . "]";
|
|
} else {
|
|
$output = "";
|
|
}
|
|
break;
|
|
|
|
case "li":
|
|
$output .= "\n";
|
|
break;
|
|
|
|
case "blockquote":
|
|
// process quoted text for whitespace/newlines
|
|
$output = static::processWhitespaceNewlines($output);
|
|
|
|
// add leading newline
|
|
$output = "\n" . $output;
|
|
|
|
// prepend '> ' at the beginning of all lines
|
|
$output = preg_replace("/\n/im", "\n> ", $output);
|
|
|
|
// replace leading '> >' with '>>'
|
|
$output = preg_replace("/\n> >/im", "\n>>", $output);
|
|
|
|
// add another leading newline and trailing newlines
|
|
$output = "\n" . $output . "\n\n";
|
|
break;
|
|
default:
|
|
// do nothing
|
|
}
|
|
|
|
return $output;
|
|
}
|
|
}
|