silverstripe-framework/src/View/Parsers/ShortcodeParser.php

742 lines
25 KiB
PHP

<?php
namespace SilverStripe\View\Parsers;
use DOMNodeList;
use SilverStripe\Core\Config\Configurable;
use SilverStripe\Core\Extensible;
use SilverStripe\Core\Injector\Injectable;
use SilverStripe\Core\Injector\Injector;
use InvalidArgumentException;
use DOMElement;
/**
* A simple parser that allows you to map BBCode-like "shortcodes" to an arbitrary callback.
* It is a simple regex based parser that allows you to replace simple bbcode-like tags
* within a DBHTMLText or DBHTMLVarchar field when rendered into a template. The API is inspired by and very similar to the
* [Wordpress implementation](http://codex.wordpress.org/Shortcode_API) of shortcodes.
*
* @see http://doc.silverstripe.org/framework/en/reference/shortcodes
*/
class ShortcodeParser
{
use Injectable;
use Configurable;
use Extensible;
public function __construct()
{
}
public function img_shortcode($attrs)
{
return "<img src='" . $attrs['src'] . "'>";
}
protected static $instances = array();
protected static $active_instance = 'default';
// --------------------------------------------------------------------------------------------------------------
/**
* Registered shortcodes. Items follow this structure:
* [shortcode_name] => Array(
* [0] => class_containing_handler
* [1] => name_of_shortcode_handler_method
* )
*/
protected $shortcodes = array();
// --------------------------------------------------------------------------------------------------------------
/**
* Get the {@link ShortcodeParser} instance that is attached to a particular identifier.
*
* @param string $identifier Defaults to "default".
* @return ShortcodeParser
*/
public static function get($identifier = 'default')
{
if (!array_key_exists($identifier, self::$instances)) {
self::$instances[$identifier] = static::create();
}
return self::$instances[$identifier];
}
/**
* Get the currently active/default {@link ShortcodeParser} instance.
*
* @return ShortcodeParser
*/
public static function get_active()
{
return static::get(self::$active_instance);
}
/**
* Set the identifier to use for the current active/default {@link ShortcodeParser} instance.
*
* @param string $identifier
*/
public static function set_active($identifier)
{
self::$active_instance = (string) $identifier;
}
// --------------------------------------------------------------------------------------------------------------
/**
* Register a shortcode, and attach it to a PHP callback.
*
* The callback for a shortcode will have the following arguments passed to it:
* - Any parameters attached to the shortcode as an associative array (keys are lower-case).
* - Any content enclosed within the shortcode (if it is an enclosing shortcode). Note that any content within
* this will not have been parsed, and can optionally be fed back into the parser.
* - The {@link ShortcodeParser} instance used to parse the content.
* - The shortcode tag name that was matched within the parsed content.
* - An associative array of extra information about the shortcode being parsed.
*
* @param string $shortcode The shortcode tag to map to the callback - normally in lowercase_underscore format.
* @param callback $callback The callback to replace the shortcode with.
* @return $this
*/
public function register($shortcode, $callback)
{
if (is_callable($callback)) {
$this->shortcodes[$shortcode] = $callback;
} else {
throw new InvalidArgumentException("Callback is not callable");
}
return $this;
}
/**
* Check if a shortcode has been registered.
*
* @param string $shortcode
* @return bool
*/
public function registered($shortcode)
{
return array_key_exists($shortcode, $this->shortcodes);
}
/**
* Remove a specific registered shortcode.
*
* @param string $shortcode
*/
public function unregister($shortcode)
{
if ($this->registered($shortcode)) {
unset($this->shortcodes[$shortcode]);
}
}
/**
* Get an array containing information about registered shortcodes
*
* @return array
*/
public function getRegisteredShortcodes()
{
return $this->shortcodes;
}
/**
* Remove all registered shortcodes.
*/
public function clear()
{
$this->shortcodes = array();
}
/**
* Call a shortcode and return its replacement text
* Returns false if the shortcode isn't registered
*
* @param string $tag
* @param array $attributes
* @param string $content
* @param array $extra
* @return mixed
*/
public function callShortcode($tag, $attributes, $content, $extra = array())
{
if (!$tag || !isset($this->shortcodes[$tag])) {
return false;
}
return call_user_func($this->shortcodes[$tag], $attributes, $content, $this, $tag, $extra);
}
/**
* Return the text to insert in place of a shoprtcode.
* Behaviour in the case of missing shortcodes depends on the setting of ShortcodeParser::$error_behavior.
*
* @param array $tag A map containing the the following keys:
* - 'open': The name of the tag
* - 'attrs': Attributes of the tag
* - 'content': Content of the tag
* @param array $extra Extra-meta data
* @param boolean $isHTMLAllowed A boolean indicating whether it's okay to insert HTML tags into the result
*
* @return bool|mixed|string
*/
public function getShortcodeReplacementText($tag, $extra = array(), $isHTMLAllowed = true)
{
$content = $this->callShortcode($tag['open'], $tag['attrs'], $tag['content'], $extra);
// Missing tag
if ($content === false) {
if (ShortcodeParser::$error_behavior == ShortcodeParser::ERROR) {
user_error('Unknown shortcode tag ' . $tag['open'], E_USER_ERROR);
} elseif (self::$error_behavior == self::WARN && $isHTMLAllowed) {
$content = '<strong class="warning">' . $tag['text'] . '</strong>';
} elseif (ShortcodeParser::$error_behavior == ShortcodeParser::STRIP) {
return '';
} else {
return $tag['text'];
}
}
return $content;
}
// --------------------------------------------------------------------------------------------------------------
protected function removeNode($node)
{
$node->parentNode->removeChild($node);
}
/**
* @param DOMElement $new
* @param DOMElement $after
*/
protected function insertAfter($new, $after)
{
$parent = $after->parentNode;
$next = $after->nextSibling;
if ($next) {
$parent->insertBefore($new, $next);
} elseif ($parent) {
$parent->appendChild($new);
}
}
/**
* @param DOMNodeList $new
* @param DOMElement $after
*/
protected function insertListAfter($new, $after)
{
$doc = $after->ownerDocument;
$parent = $after->parentNode;
$next = $after->nextSibling;
for ($i = 0; $i < $new->length; $i++) {
$imported = $doc->importNode($new->item($i), true);
if ($next) {
$parent->insertBefore($imported, $next);
} else {
$parent->appendChild($imported);
}
}
}
/**
* @var string
*/
protected static $marker_class = '--ss-shortcode-marker';
protected static $block_level_elements = array(
'address', 'article', 'aside', 'audio', 'blockquote', 'canvas', 'dd', 'div', 'dl', 'fieldset', 'figcaption',
'figure', 'footer', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'header', 'hgroup', 'ol', 'output', 'p',
'pre', 'section', 'table', 'ul'
);
protected static $attrrx = '
([^\s\/\'"=,]+) # Name
\s* = \s*
(?:
(?:\'([^\']+)\') | # Value surrounded by \'
(?:"([^"]+)") | # Value surrounded by "
([^\s,\]]+) # Bare value
)
';
protected static function attrrx()
{
return '/' . self::$attrrx . '/xS';
}
protected static $tagrx = '
# HTML Tag
<(?<element>(?:"[^"]*"[\'"]*|\'[^\']*\'[\'"]*|[^\'">])+)>
| # Opening tag
(?<oesc>\[?)
\[
(?<open>\w+)
[\s,]*
(?<attrs> (?: %s [\s,]*)* )
\/?\]
(?<cesc1>\]?)
| # Closing tag
\[\/
(?<close>\w+)
\]
(?<cesc2>\]?)
';
protected static function tagrx()
{
return '/' . sprintf(self::$tagrx, self::$attrrx) . '/xS';
}
const WARN = 'warn';
const STRIP = 'strip';
const LEAVE = 'leave';
const ERROR = 'error';
public static $error_behavior = self::LEAVE;
/**
* Look through a string that contains shortcode tags and pull out the locations and details
* of those tags
*
* Doesn't support nested shortcode tags
*
* @param string $content
* @return array - The list of tags found. When using an open/close pair, only one item will be in the array,
* with "content" set to the text between the tags
*/
public function extractTags($content)
{
$tags = array();
// Step 1: perform basic regex scan of individual tags
if (preg_match_all(static::tagrx(), $content, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE)) {
foreach ($matches as $match) {
// Ignore any elements
if (empty($match['open'][0]) && empty($match['close'][0])) {
continue;
}
// Pull the attributes out into a key/value hash
$attrs = array();
if (!empty($match['attrs'][0])) {
preg_match_all(static::attrrx(), $match['attrs'][0], $attrmatches, PREG_SET_ORDER);
foreach ($attrmatches as $attr) {
$name = '';
$value = '';
$parts = array_values(array_filter($attr));
//the first element in the array is the complete delcaration (`id=1`) - we don't need this
array_shift($parts);
//the next two parts are what we care about (id and 1 from `id=1`)
$name = array_shift($parts) ?: $name;
$value = array_shift($parts) ?: $value;
$attrs[$name] = $value;
}
}
// And store the indexes, tag details, etc
$tags[] = array(
'text' => $match[0][0],
's' => $match[0][1],
'e' => $match[0][1] + strlen($match[0][0]),
'open' => isset($match['open'][0]) ? $match['open'][0] : null,
'close' => isset($match['close'][0]) ? $match['close'][0] : null,
'attrs' => $attrs,
'content' => '',
'escaped' => !empty($match['oesc'][0]) || !empty($match['cesc1'][0]) || !empty($match['cesc2'][0])
);
}
}
// Step 2: cluster open/close tag pairs into single entries
$i = count($tags);
while ($i--) {
if (!empty($tags[$i]['close'])) {
// If the tag just before this one isn't the related opening tag, throw an error
$err = null;
if ($i == 0) {
$err = 'Close tag "' . $tags[$i]['close'] . '" is the first found tag, so has no related open tag';
} elseif (!$tags[$i-1]['open']) {
$err = 'Close tag "' . $tags[$i]['close'] . '" preceded by another close tag "' . $tags[$i-1]['close'] . '"';
} elseif ($tags[$i]['close'] != $tags[$i-1]['open']) {
$err = 'Close tag "' . $tags[$i]['close'] . '" doesn\'t match preceding open tag "' . $tags[$i-1]['open'] . '"';
}
if ($err) {
if (self::$error_behavior == self::ERROR) {
user_error($err, E_USER_ERROR);
}
} else {
if ($tags[$i]['escaped']) {
if (!$tags[$i-1]['escaped']) {
$tags[$i]['e'] -= 1;
$tags[$i]['escaped'] = false;
}
} else {
if ($tags[$i-1]['escaped']) {
$tags[$i-1]['s'] += 1;
$tags[$i-1]['escaped'] = false;
}
}
// Otherwise, grab content between tags, save in opening tag & delete the closing one
$tags[$i-1]['text'] = substr($content, $tags[$i-1]['s'], $tags[$i]['e'] - $tags[$i-1]['s']);
$tags[$i-1]['content'] = substr($content, $tags[$i-1]['e'], $tags[$i]['s'] - $tags[$i-1]['e']);
$tags[$i-1]['e'] = $tags[$i]['e'];
unset($tags[$i]);
}
}
}
// Step 3: remove any tags that don't have handlers registered
// Only do this if self::$error_behavior == self::LEAVE
// This is optional but speeds things up.
if (self::$error_behavior == self::LEAVE) {
foreach ($tags as $i => $tag) {
if (empty($this->shortcodes[$tag['open']])) {
unset($tags[$i]);
}
}
}
return array_values($tags);
}
/**
* Replaces the shortcode tags extracted by extractTags with HTML element "markers", so that
* we can parse the resulting string as HTML and easily mutate the shortcodes in the DOM
*
* @param string $content The HTML string with [tag] style shortcodes embedded
* @param array $tags The tags extracted by extractTags
* @param callable $generator
* @return string The HTML string with [tag] style shortcodes replaced by markers
*/
protected function replaceTagsWithText($content, $tags, $generator)
{
// The string with tags replaced with markers
$str = '';
// The start index of the next tag, remembered as we step backwards through the list
$li = null;
$i = count($tags);
while ($i--) {
if ($li === null) {
$tail = substr($content, $tags[$i]['e']);
} else {
$tail = substr($content, $tags[$i]['e'], $li - $tags[$i]['e']);
}
if ($tags[$i]['escaped']) {
$str = substr($content, $tags[$i]['s']+1, $tags[$i]['e'] - $tags[$i]['s'] - 2) . $tail . $str;
} else {
$str = $generator($i, $tags[$i]) . $tail . $str;
}
$li = $tags[$i]['s'];
}
return substr($content, 0, $tags[0]['s']) . $str;
}
/**
* Replace the shortcodes in attribute values with the calculated content
*
* We don't use markers with attributes because there's no point, it's easier to do all the matching
* in-DOM after the XML parse
*
* @param HTMLValue $htmlvalue
*/
protected function replaceAttributeTagsWithContent($htmlvalue)
{
$attributes = $htmlvalue->query('//@*[contains(.,"[")][contains(.,"]")]');
$parser = $this;
for ($i = 0; $i < $attributes->length; $i++) {
$node = $attributes->item($i);
$tags = $this->extractTags($node->nodeValue);
$extra = array('node' => $node, 'element' => $node->ownerElement);
if ($tags) {
$node->nodeValue = $this->replaceTagsWithText(
htmlspecialchars($node->nodeValue),
$tags,
function ($idx, $tag) use ($parser, $extra) {
return $parser->getShortcodeReplacementText($tag, $extra, false);
}
);
}
}
}
/**
* Replace the element-scoped tags with markers
*
* @param string $content
* @return array
*/
protected function replaceElementTagsWithMarkers($content)
{
$tags = $this->extractTags($content);
if ($tags) {
$markerClass = self::$marker_class;
$content = $this->replaceTagsWithText($content, $tags, function ($idx, $tag) use ($markerClass) {
return '<img class="' . $markerClass . '" data-tagid="' . $idx . '" />';
});
}
return array($content, $tags);
}
/**
* @param DOMNodeList $nodes
* @return array
*/
protected function findParentsForMarkers($nodes)
{
$parents = array();
/** @var DOMElement $node */
foreach ($nodes as $node) {
$parent = $node;
do {
$parent = $parent->parentNode;
} while ($parent instanceof DOMElement &&
!in_array(strtolower($parent->tagName), self::$block_level_elements)
);
$node->setAttribute('data-parentid', count($parents));
$parents[] = $parent;
}
return $parents;
}
const BEFORE = 'before';
const AFTER = 'after';
const SPLIT = 'split';
const INLINE = 'inline';
/**
* Given a node with represents a shortcode marker and a location string, mutates the DOM to put the
* marker in the compliant location
*
* For shortcodes inserted BEFORE, that location is just before the block container that
* the marker is in
*
* For shortcodes inserted AFTER, that location is just after the block container that
* the marker is in
*
* For shortcodes inserted SPLIT, that location is where the marker is, but the DOM
* is split around it up to the block container the marker is in - for instance,
*
* <p>A<span>B<marker />C</span>D</p>
*
* becomes
*
* <p>A<span>B</span></p><marker /><p><span>C</span>D</p>
*
* For shortcodes inserted INLINE, no modification is needed (but in that case the shortcode handler needs to
* generate only inline blocks)
*
* @param DOMElement $node
* @param DOMElement $parent
* @param int $location ShortcodeParser::BEFORE, ShortcodeParser::SPLIT or ShortcodeParser::INLINE
*/
protected function moveMarkerToCompliantHome($node, $parent, $location)
{
// Move before block parent
if ($location == self::BEFORE) {
if (isset($parent->parentNode)) {
$parent->parentNode->insertBefore($node, $parent);
}
} elseif ($location == self::AFTER) {
// Move after block parent
$this->insertAfter($node, $parent);
} elseif ($location == self::SPLIT) {
// Split parent at node
$at = $node;
$splitee = $node->parentNode;
while ($splitee !== $parent->parentNode) {
/** @var DOMElement $spliter */
$spliter = $splitee->cloneNode(false);
$this->insertAfter($spliter, $splitee);
while ($at->nextSibling) {
$spliter->appendChild($at->nextSibling);
}
$at = $splitee;
$splitee = $splitee->parentNode;
}
$this->insertAfter($node, $parent);
} elseif ($location == self::INLINE) {
// Do nothing
if (in_array(strtolower($node->tagName), self::$block_level_elements)) {
user_error(
'Requested to insert block tag ' . $node->tagName . ' inline - probably this will break HTML compliance',
E_USER_WARNING
);
}
// NOP
} else {
user_error('Unknown value for $location argument ' . $location, E_USER_ERROR);
}
}
/**
* Given a node with represents a shortcode marker and some information about the shortcode, call the
* shortcode handler & replace the marker with the actual content
*
* @param DOMElement $node
* @param array $tag
*/
protected function replaceMarkerWithContent($node, $tag)
{
$content = $this->getShortcodeReplacementText($tag);
if ($content) {
/** @var HTMLValue $parsed */
$parsed = HTMLValue::create($content);
$body = $parsed->getBody();
if ($body) {
$this->insertListAfter($body->childNodes, $node);
}
}
$this->removeNode($node);
}
/**
* Parse a string, and replace any registered shortcodes within it with the result of the mapped callback.
*
* @param string $content
* @return string
*/
public function parse($content)
{
$this->extend('onBeforeParse', $content);
$continue = true;
// If no shortcodes defined, don't try and parse any
if (!$this->shortcodes) {
$continue = false;
} elseif (!trim($content)) {
// If no content, don't try and parse it
$continue = false;
} elseif (strpos($content, '[') === false) {
// If no shortcode tag, don't try and parse it
$continue = false;
}
if ($continue) {
// First we operate in text mode, replacing any shortcodes with marker elements so that later we can
// use a proper DOM
list($content, $tags) = $this->replaceElementTagsWithMarkers($content);
/** @var HTMLValue $htmlvalue */
$htmlvalue = Injector::inst()->create('HTMLValue', $content);
// Now parse the result into a DOM
if (!$htmlvalue->isValid()) {
if (self::$error_behavior == self::ERROR) {
user_error('Couldn\'t decode HTML when processing short codes', E_USER_ERROR);
} else {
$continue = false;
}
}
}
if ($continue) {
// First, replace any shortcodes that are in attributes
$this->replaceAttributeTagsWithContent($htmlvalue);
// Find all the element scoped shortcode markers
$shortcodes = $htmlvalue->query('//img[@class="' . self::$marker_class . '"]');
// Find the parents. Do this before DOM modification, since SPLIT might cause parents to move otherwise
$parents = $this->findParentsForMarkers($shortcodes);
/** @var DOMElement $shortcode */
foreach ($shortcodes as $shortcode) {
$tag = $tags[$shortcode->getAttribute('data-tagid')];
$parent = $parents[$shortcode->getAttribute('data-parentid')];
$class = null;
if (!empty($tag['attrs']['location'])) {
$class = $tag['attrs']['location'];
} elseif (!empty($tag['attrs']['class'])) {
$class = $tag['attrs']['class'];
}
$location = self::INLINE;
if ($class == 'left' || $class == 'right') {
$location = self::BEFORE;
}
/**
* Below code disabled due to https://github.com/silverstripe/silverstripe-framework/issues/5987
if ($class == 'center' || $class == 'leftAlone') {
$location = self::SPLIT;
}
*/
if (!$parent) {
if ($location !== self::INLINE) {
user_error(
"Parent block for shortcode couldn't be found, but location wasn't INLINE",
E_USER_ERROR
);
}
} else {
$this->moveMarkerToCompliantHome($shortcode, $parent, $location);
}
$this->replaceMarkerWithContent($shortcode, $tag);
}
$content = $htmlvalue->getContent();
// Clean up any marker classes left over, for example, those injected into <script> tags
$parser = $this;
$content = preg_replace_callback(
// Not a general-case parser; assumes that the HTML generated in replaceElementTagsWithMarkers()
// hasn't been heavily modified
'/<img[^>]+class="' . preg_quote(self::$marker_class) . '"[^>]+data-tagid="([^"]+)"[^>]*>/i',
function ($matches) use ($tags, $parser) {
$tag = $tags[$matches[1]];
return $parser->getShortcodeReplacementText($tag);
},
$content
);
}
$this->extend('onAfterParse', $content);
return $content;
}
}