<?php
/**
* Generates HTML from tokens.
* @todo Refactor interface so that configuration/context is determined
* upon instantiation, no need for messy generateFromTokens() calls
* @todo Make some of the more internal functions protected, and have
* unit tests work around that
*/
class HTMLPurifier_Generator
{
/**
* Whether or not generator should produce XML output.
* @type bool
*/
private $_xhtml = true;
/**
* :HACK: Whether or not generator should comment the insides of <script> tags.
* @type bool
*/
private $_scriptFix = false;
/**
* Cache of HTMLDefinition during HTML output to determine whether or
* not attributes should be minimized.
* @type HTMLPurifier_HTMLDefinition
*/
private $_def;
/**
* Cache of %Output.SortAttr.
* @type bool
*/
private $_sortAttr;
/**
* Cache of %Output.FlashCompat.
* @type bool
*/
private $_flashCompat;
/**
* Cache of %Output.FixInnerHTML.
* @type bool
*/
private $_innerHTMLFix;
/**
* Stack for keeping track of object information when outputting IE
* compatibility code.
* @type array
*/
private $_flashStack = array();
/**
* Configuration for the generator
* @type HTMLPurifier_Config
*/
protected $config;
/**
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
*/
public function __construct($config, $context)
{
$this->config = $config;
$this->_scriptFix = $config->get('Output.CommentScriptContents');
$this->_innerHTMLFix = $config->get('Output.FixInnerHTML');
$this->_sortAttr = $config->get('Output.SortAttr');
$this->_flashCompat = $config->get('Output.FlashCompat');
$this->_def = $config->getHTMLDefinition();
$this->_xhtml = $this->_def->doctype->xml;
}
/**
* Generates HTML from an array of tokens.
* @param HTMLPurifier_Token[] $tokens Array of HTMLPurifier_Token
* @return string Generated HTML
*/
public function generateFromTokens($tokens)
{
if (!$tokens) {
return '';
}
// Basic algorithm
$html = '';
for ($i = 0, $size = count($tokens); $i < $size; $i++) {
if ($this->_scriptFix && $tokens[$i]->name === 'script'
&& $i + 2 < $size && $tokens[$i+2] instanceof HTMLPurifier_Token_End) {
// script special case
// the contents of the script block must be ONE token
// for this to work.
$html .= $this->generateFromToken($tokens[$i++]);
$html .= $this->generateScriptFromToken($tokens[$i++]);
}
$html .= $this->generateFromToken($tokens[$i]);
}
// Tidy cleanup
if (extension_loaded('tidy') && $this->config->get('Output.TidyFormat')) {
$tidy = new Tidy;
$tidy->parseString(
$html,
array(
'indent'=> true,
'output-xhtml' => $this->_xhtml,
'show-body-only' => true,
'indent-spaces' => 2,
'wrap' => 68,
),
'utf8'
);
$tidy->cleanRepair();
$html = (string) $tidy; // explicit cast necessary
}
// Normalize newlines to system defined value
if ($this->config->get('Core.NormalizeNewlines')) {
$nl = $this->config->get('Output.Newline');
if ($nl === null) {
$nl = PHP_EOL;
}
if ($nl !== "\n") {
$html = str_replace("\n", $nl, $html);
}
}
return $html;
}
/**
* Generates HTML from a single token.
* @param HTMLPurifier_Token $token HTMLPurifier_Token object.
* @return string Generated HTML
*/
public function generateFromToken($token)
{
if (!$token instanceof HTMLPurifier_Token) {
trigger_error('Cannot generate HTML from non-HTMLPurifier_Token object', E_USER_WARNING);
return '';
} elseif ($token instanceof HTMLPurifier_Token_Start) {
$attr = $this->generateAttributes($token->attr, $token->name);
if ($this->_flashCompat) {
if ($token->name == "object") {
$flash = new stdClass();
$flash->attr = $token->attr;
$flash->param = array();
$this->_flashStack[] = $flash;
}
}
return '<' . $token->name . ($attr ? ' ' : '') . $attr . '>';
} elseif ($token instanceof HTMLPurifier_Token_End) {
$_extra = '';
if ($this->_flashCompat) {
if ($token->name == "object" && !empty($this->_flashStack)) {
// doesn't do anything for now
}
}
return $_extra . '</' . $token->name . '>';
} elseif ($token instanceof HTMLPurifier_Token_Empty) {
if ($this->_flashCompat && $token->name == "param" && !empty($this->_flashStack)) {
$this->_flashStack[count($this->_flashStack)-1]->param[$token->attr['name']] = $token->attr['value'];
}
$attr = $this->generateAttributes($token->attr, $token->name);
return '<' . $token->name . ($attr ? ' ' : '') . $attr .
( $this->_xhtml ? ' /': '' ) // <br /> v. <br>
. '>';
} elseif ($token instanceof HTMLPurifier_Token_Text) {
return $this->escape($token->data, ENT_NOQUOTES);
} elseif ($token instanceof HTMLPurifier_Token_Comment) {
return '<!--' . $token->data . '-->';
} else {
return '';
}
}
/**
* Special case processor for the contents of script tags
* @param HTMLPurifier_Token $token HTMLPurifier_Token object.
* @return string
* @warning This runs into problems if there's already a literal
* --> somewhere inside the script contents.
*/
public function generateScriptFromToken($token)
{
if (!$token instanceof HTMLPurifier_Token_Text) {
return $this->generateFromToken($token);
}
// Thanks <http://lachy.id.au/log/2005/05/script-comments>
$data = preg_replace('#//\s*$#', '', $token->data);
return '<!--//--><![CDATA[//><!--' . "\n" . trim($data) . "\n" . '//--><!]]>';
}
/**
* Generates attribute declarations from attribute array.
* @note This does not include the leading or trailing space.
* @param array $assoc_array_of_attributes Attribute array
* @param string $element Name of element attributes are for, used to check
* attribute minimization.
* @return string Generated HTML fragment for insertion.
*/
public function generateAttributes($assoc_array_of_attributes, $element = '')
{
$html = '';
if ($this->_sortAttr) {
ksort($assoc_array_of_attributes);
}
foreach ($assoc_array_of_attributes as $key => $value) {
if (!$this->_xhtml) {
// Remove namespaced attributes
if (strpos($key, ':') !== false) {
continue;
}
// Check if we should minimize the attribute: val="val" -> val
if ($element && !empty($this->_def->info[$element]->attr[$key]->minimized)) {
$html .= $key . ' ';
continue;
}
}
// Workaround for Internet Explorer innerHTML bug.
// Essentially, Internet Explorer, when calculating
// innerHTML, omits quotes if there are no instances of
// angled brackets, quotes or spaces. However, when parsing
// HTML (for example, when you assign to innerHTML), it
// treats backticks as quotes. Thus,
// <img alt="``" />
// becomes
// <img alt=`` />
// becomes
// <img alt='' />
// Fortunately, all we need to do is trigger an appropriate
// quoting style, which we do by adding an extra space.
// This also is consistent with the W3C spec, which states
// that user agents may ignore leading or trailing
// whitespace (in fact, most don't, at least for attributes
// like alt, but an extra space at the end is barely
// noticeable). Still, we have a configuration knob for
// this, since this transformation is not necesary if you
// don't process user input with innerHTML or you don't plan
// on supporting Internet Explorer.
if ($this->_innerHTMLFix) {
if (strpos($value, '`') !== false) {
// check if correct quoting style would not already be
// triggered
if (strcspn($value, '"\' <>') === strlen($value)) {
// protect!
$value .= ' ';
}
}
}
$html .= $key.'="'.$this->escape($value).'" ';
}
return rtrim($html);
}
/**
* Escapes raw text data.
* @todo This really ought to be protected, but until we have a facility
* for properly generating HTML here w/o using tokens, it stays
* public.
* @param string $string String data to escape for HTML.
* @param int $quote Quoting style, like htmlspecialchars. ENT_NOQUOTES is
* permissible for non-attribute output.
* @return string escaped data.
*/
public function escape($string, $quote = null)
{
// Workaround for APC bug on Mac Leopard reported by sidepodcast
// http://htmlpurifier.org/phorum/read.php?3,4823,4846
if ($quote === null) {
$quote = ENT_COMPAT;
}
return htmlspecialchars($string, $quote, 'UTF-8');
}
}
// vim: et sw=4 sts=4