--- /dev/null
+<?php
+namespace Masterminds\HTML5\Parser;
+
+use Masterminds\HTML5\Elements;
+
+/**
+ * Create an HTML5 DOM tree from events.
+ *
+ * This attempts to create a DOM from events emitted by a parser. This
+ * attempts (but does not guarantee) to up-convert older HTML documents
+ * to HTML5. It does this by applying HTML5's rules, but it will not
+ * change the architecture of the document itself.
+ *
+ * Many of the error correction and quirks features suggested in the specification
+ * are implemented herein; however, not all of them are. Since we do not
+ * assume a graphical user agent, no presentation-specific logic is conducted
+ * during tree building.
+ *
+ * FIXME: The present tree builder does not exactly follow the state machine rules
+ * for insert modes as outlined in the HTML5 spec. The processor needs to be
+ * re-written to accomodate this. See, for example, the Go language HTML5
+ * parser.
+ */
+class DOMTreeBuilder implements EventHandler
+{
+ /**
+ * Defined in http://www.w3.org/TR/html51/infrastructure.html#html-namespace-0
+ */
+ const NAMESPACE_HTML = 'http://www.w3.org/1999/xhtml';
+
+ const NAMESPACE_MATHML = 'http://www.w3.org/1998/Math/MathML';
+
+ const NAMESPACE_SVG = 'http://www.w3.org/2000/svg';
+
+ const NAMESPACE_XLINK = 'http://www.w3.org/1999/xlink';
+
+ const NAMESPACE_XML = 'http://www.w3.org/XML/1998/namespace';
+
+ const NAMESPACE_XMLNS = 'http://www.w3.org/2000/xmlns/';
+
+ const OPT_DISABLE_HTML_NS = 'disable_html_ns';
+
+ const OPT_TARGET_DOC = 'target_document';
+
+ const OPT_IMPLICIT_NS = 'implicit_namespaces';
+
+ /**
+ * Holds the HTML5 element names that causes a namespace switch
+ *
+ * @var array
+ */
+ protected $nsRoots = array(
+ 'html' => self::NAMESPACE_HTML,
+ 'svg' => self::NAMESPACE_SVG,
+ 'math' => self::NAMESPACE_MATHML
+ );
+
+ /**
+ * Holds the always available namespaces (which does not require the XMLNS declaration).
+ *
+ * @var array
+ */
+ protected $implicitNamespaces = array(
+ 'xml' => self::NAMESPACE_XML,
+ 'xmlns' => self::NAMESPACE_XMLNS,
+ 'xlink' => self::NAMESPACE_XLINK
+ );
+
+ /**
+ * Holds a stack of currently active namespaces.
+ *
+ * @var array
+ */
+ protected $nsStack = array();
+
+ /**
+ * Holds the number of namespaces declared by a node.
+ *
+ * @var array
+ */
+ protected $pushes = array();
+
+ /**
+ * Defined in 8.2.5.
+ */
+ const IM_INITIAL = 0;
+
+ const IM_BEFORE_HTML = 1;
+
+ const IM_BEFORE_HEAD = 2;
+
+ const IM_IN_HEAD = 3;
+
+ const IM_IN_HEAD_NOSCRIPT = 4;
+
+ const IM_AFTER_HEAD = 5;
+
+ const IM_IN_BODY = 6;
+
+ const IM_TEXT = 7;
+
+ const IM_IN_TABLE = 8;
+
+ const IM_IN_TABLE_TEXT = 9;
+
+ const IM_IN_CAPTION = 10;
+
+ const IM_IN_COLUMN_GROUP = 11;
+
+ const IM_IN_TABLE_BODY = 12;
+
+ const IM_IN_ROW = 13;
+
+ const IM_IN_CELL = 14;
+
+ const IM_IN_SELECT = 15;
+
+ const IM_IN_SELECT_IN_TABLE = 16;
+
+ const IM_AFTER_BODY = 17;
+
+ const IM_IN_FRAMESET = 18;
+
+ const IM_AFTER_FRAMESET = 19;
+
+ const IM_AFTER_AFTER_BODY = 20;
+
+ const IM_AFTER_AFTER_FRAMESET = 21;
+
+ const IM_IN_SVG = 22;
+
+ const IM_IN_MATHML = 23;
+
+ protected $options = array();
+
+ protected $stack = array();
+
+ protected $current; // Pointer in the tag hierarchy.
+ protected $doc;
+
+ protected $frag;
+
+ protected $processor;
+
+ protected $insertMode = 0;
+
+ /**
+ * Track if we are in an element that allows only inline child nodes
+ * @var string|null
+ */
+ protected $onlyInline;
+
+ /**
+ * Quirks mode is enabled by default.
+ * Any document that is missing the
+ * DT will be considered to be in quirks mode.
+ */
+ protected $quirks = true;
+
+ protected $errors = array();
+
+ public function __construct($isFragment = false, array $options = array())
+ {
+ $this->options = $options;
+
+ if (isset($options[self::OPT_TARGET_DOC])) {
+ $this->doc = $options[self::OPT_TARGET_DOC];
+ } else {
+ $impl = new \DOMImplementation();
+ // XXX:
+ // Create the doctype. For now, we are always creating HTML5
+ // documents, and attempting to up-convert any older DTDs to HTML5.
+ $dt = $impl->createDocumentType('html');
+ // $this->doc = \DOMImplementation::createDocument(NULL, 'html', $dt);
+ $this->doc = $impl->createDocument(null, null, $dt);
+ }
+ $this->errors = array();
+
+ $this->current = $this->doc; // ->documentElement;
+
+ // Create a rules engine for tags.
+ $this->rules = new TreeBuildingRules($this->doc);
+
+ $implicitNS = array();
+ if (isset($this->options[self::OPT_IMPLICIT_NS])) {
+ $implicitNS = $this->options[self::OPT_IMPLICIT_NS];
+ } elseif (isset($this->options["implicitNamespaces"])) {
+ $implicitNS = $this->options["implicitNamespaces"];
+ }
+
+ // Fill $nsStack with the defalut HTML5 namespaces, plus the "implicitNamespaces" array taken form $options
+ array_unshift($this->nsStack, $implicitNS + array(
+ '' => self::NAMESPACE_HTML
+ ) + $this->implicitNamespaces);
+
+ if ($isFragment) {
+ $this->insertMode = static::IM_IN_BODY;
+ $this->frag = $this->doc->createDocumentFragment();
+ $this->current = $this->frag;
+ }
+ }
+
+ /**
+ * Get the document.
+ */
+ public function document()
+ {
+ return $this->doc;
+ }
+
+ /**
+ * Get the DOM fragment for the body.
+ *
+ * This returns a DOMNodeList because a fragment may have zero or more
+ * DOMNodes at its root.
+ *
+ * @see http://www.w3.org/TR/2012/CR-html5-20121217/syntax.html#concept-frag-parse-context
+ *
+ * @return \DOMFragmentDocumentFragment
+ */
+ public function fragment()
+ {
+ return $this->frag;
+ }
+
+ /**
+ * Provide an instruction processor.
+ *
+ * This is used for handling Processor Instructions as they are
+ * inserted. If omitted, PI's are inserted directly into the DOM tree.
+ */
+ public function setInstructionProcessor(\Masterminds\HTML5\InstructionProcessor $proc)
+ {
+ $this->processor = $proc;
+ }
+
+ public function doctype($name, $idType = 0, $id = null, $quirks = false)
+ {
+ // This is used solely for setting quirks mode. Currently we don't
+ // try to preserve the inbound DT. We convert it to HTML5.
+ $this->quirks = $quirks;
+
+ if ($this->insertMode > static::IM_INITIAL) {
+ $this->parseError("Illegal placement of DOCTYPE tag. Ignoring: " . $name);
+
+ return;
+ }
+
+ $this->insertMode = static::IM_BEFORE_HTML;
+ }
+
+ /**
+ * Process the start tag.
+ *
+ * @todo - XMLNS namespace handling (we need to parse, even if it's not valid)
+ * - XLink, MathML and SVG namespace handling
+ * - Omission rules: 8.1.2.4 Optional tags
+ */
+ public function startTag($name, $attributes = array(), $selfClosing = false)
+ {
+ // fprintf(STDOUT, $name);
+ $lname = $this->normalizeTagName($name);
+
+ // Make sure we have an html element.
+ if (! $this->doc->documentElement && $name !== 'html' && ! $this->frag) {
+ $this->startTag('html');
+ }
+
+ // Set quirks mode if we're at IM_INITIAL with no doctype.
+ if ($this->insertMode == static::IM_INITIAL) {
+ $this->quirks = true;
+ $this->parseError("No DOCTYPE specified.");
+ }
+
+ // SPECIAL TAG HANDLING:
+ // Spec says do this, and "don't ask."
+ if ($name == 'image') {
+ $name = 'img';
+ }
+
+ // Autoclose p tags where appropriate.
+ if ($this->insertMode >= static::IM_IN_BODY && Elements::isA($name, Elements::AUTOCLOSE_P)) {
+ $this->autoclose('p');
+ }
+
+ // Set insert mode:
+ switch ($name) {
+ case 'html':
+ $this->insertMode = static::IM_BEFORE_HEAD;
+ break;
+ case 'head':
+ if ($this->insertMode > static::IM_BEFORE_HEAD) {
+ $this->parseError("Unexpected head tag outside of head context.");
+ } else {
+ $this->insertMode = static::IM_IN_HEAD;
+ }
+ break;
+ case 'body':
+ $this->insertMode = static::IM_IN_BODY;
+ break;
+ case 'svg':
+ $this->insertMode = static::IM_IN_SVG;
+ break;
+ case 'math':
+ $this->insertMode = static::IM_IN_MATHML;
+ break;
+ case 'noscript':
+ if ($this->insertMode == static::IM_IN_HEAD) {
+ $this->insertMode = static::IM_IN_HEAD_NOSCRIPT;
+ }
+ break;
+ }
+
+ // Special case handling for SVG.
+ if ($this->insertMode == static::IM_IN_SVG) {
+ $lname = Elements::normalizeSvgElement($lname);
+ }
+
+ $pushes = 0;
+ // when we found a tag thats appears inside $nsRoots, we have to switch the defalut namespace
+ if (isset($this->nsRoots[$lname]) && $this->nsStack[0][''] !== $this->nsRoots[$lname]) {
+ array_unshift($this->nsStack, array(
+ '' => $this->nsRoots[$lname]
+ ) + $this->nsStack[0]);
+ $pushes ++;
+ }
+ $needsWorkaround = false;
+ if (isset($this->options["xmlNamespaces"]) && $this->options["xmlNamespaces"]) {
+ // when xmlNamespaces is true a and we found a 'xmlns' or 'xmlns:*' attribute, we should add a new item to the $nsStack
+ foreach ($attributes as $aName => $aVal) {
+ if ($aName === 'xmlns') {
+ $needsWorkaround = $aVal;
+ array_unshift($this->nsStack, array(
+ '' => $aVal
+ ) + $this->nsStack[0]);
+ $pushes ++;
+ } elseif ((($pos = strpos($aName, ':')) ? substr($aName, 0, $pos) : '') === 'xmlns') {
+ array_unshift($this->nsStack, array(
+ substr($aName, $pos + 1) => $aVal
+ ) + $this->nsStack[0]);
+ $pushes ++;
+ }
+ }
+ }
+
+ if ($this->onlyInline && Elements::isA($lname, Elements::BLOCK_TAG)) {
+ $this->autoclose($this->onlyInline);
+ $this->onlyInline = null;
+ }
+
+ try {
+ $prefix = ($pos = strpos($lname, ':')) ? substr($lname, 0, $pos) : '';
+
+
+ if ($needsWorkaround!==false) {
+
+ $xml = "<$lname xmlns=\"$needsWorkaround\" ".(strlen($prefix) && isset($this->nsStack[0][$prefix])?("xmlns:$prefix=\"".$this->nsStack[0][$prefix]."\""):"")."/>";
+
+ $frag = new \DOMDocument('1.0', 'UTF-8');
+ $frag->loadXML($xml);
+
+ $ele = $this->doc->importNode($frag->documentElement, true);
+
+ } else {
+ if (!isset($this->nsStack[0][$prefix]) || ($prefix === "" && isset($this->options[self::OPT_DISABLE_HTML_NS]) && $this->options[self::OPT_DISABLE_HTML_NS])) {
+ $ele = $this->doc->createElement($lname);
+ } else {
+ $ele = $this->doc->createElementNS($this->nsStack[0][$prefix], $lname);
+ }
+ }
+
+ } catch (\DOMException $e) {
+ $this->parseError("Illegal tag name: <$lname>. Replaced with <invalid>.");
+ $ele = $this->doc->createElement('invalid');
+ }
+
+ if (Elements::isA($lname, Elements::BLOCK_ONLY_INLINE)) {
+ $this->onlyInline = $lname;
+ }
+
+ // When we add some namespacess, we have to track them. Later, when "endElement" is invoked, we have to remove them.
+ // When we are on a void tag, we do not need to care about namesapce nesting.
+ if ($pushes > 0 && !Elements::isA($name, Elements::VOID_TAG)) {
+ // PHP tends to free the memory used by DOM,
+ // to avoid spl_object_hash collisions whe have to avoid garbage collection of $ele storing it into $pushes
+ // see https://bugs.php.net/bug.php?id=67459
+ $this->pushes[spl_object_hash($ele)] = array($pushes, $ele);
+
+ // SEE https://github.com/facebook/hhvm/issues/2962
+ if (defined('HHVM_VERSION')) {
+ $ele->setAttribute('html5-php-fake-id-attribute', spl_object_hash($ele));
+ }
+ }
+
+ foreach ($attributes as $aName => $aVal) {
+ // xmlns attributes can't be set
+ if ($aName === 'xmlns') {
+ continue;
+ }
+
+ if ($this->insertMode == static::IM_IN_SVG) {
+ $aName = Elements::normalizeSvgAttribute($aName);
+ } elseif ($this->insertMode == static::IM_IN_MATHML) {
+ $aName = Elements::normalizeMathMlAttribute($aName);
+ }
+
+ try {
+ $prefix = ($pos = strpos($aName, ':')) ? substr($aName, 0, $pos) : false;
+
+ if ($prefix==='xmlns') {
+ $ele->setAttributeNs(self::NAMESPACE_XMLNS, $aName, $aVal);
+ } elseif ($prefix!==false && isset($this->nsStack[0][$prefix])) {
+ $ele->setAttributeNs($this->nsStack[0][$prefix], $aName, $aVal);
+ } else {
+ $ele->setAttribute($aName, $aVal);
+ }
+ } catch (\DOMException $e) {
+ $this->parseError("Illegal attribute name for tag $name. Ignoring: $aName");
+ continue;
+ }
+
+ // This is necessary on a non-DTD schema, like HTML5.
+ if ($aName == 'id') {
+ $ele->setIdAttribute('id', true);
+ }
+ }
+
+ // Some elements have special processing rules. Handle those separately.
+ if ($this->rules->hasRules($name) && $this->frag !== $this->current) {
+ $this->current = $this->rules->evaluate($ele, $this->current);
+ } // Otherwise, it's a standard element.
+ else {
+ $this->current->appendChild($ele);
+
+ // XXX: Need to handle self-closing tags and unary tags.
+ if (! Elements::isA($name, Elements::VOID_TAG)) {
+ $this->current = $ele;
+ }
+ }
+
+ // This is sort of a last-ditch attempt to correct for cases where no head/body
+ // elements are provided.
+ if ($this->insertMode <= static::IM_BEFORE_HEAD && $name != 'head' && $name != 'html') {
+ $this->insertMode = static::IM_IN_BODY;
+ }
+
+ // When we are on a void tag, we do not need to care about namesapce nesting,
+ // but we have to remove the namespaces pushed to $nsStack.
+ if ($pushes > 0 && Elements::isA($name, Elements::VOID_TAG)) {
+ // remove the namespaced definded by current node
+ for ($i = 0; $i < $pushes; $i ++) {
+ array_shift($this->nsStack);
+ }
+ }
+ // Return the element mask, which the tokenizer can then use to set
+ // various processing rules.
+ return Elements::element($name);
+ }
+
+ public function endTag($name)
+ {
+ $lname = $this->normalizeTagName($name);
+
+ // Ignore closing tags for unary elements.
+ if (Elements::isA($name, Elements::VOID_TAG)) {
+ return;
+ }
+
+ if ($this->insertMode <= static::IM_BEFORE_HTML) {
+ // 8.2.5.4.2
+ if (in_array($name, array(
+ 'html',
+ 'br',
+ 'head',
+ 'title'
+ ))) {
+ $this->startTag('html');
+ $this->endTag($name);
+ $this->insertMode = static::IM_BEFORE_HEAD;
+
+ return;
+ }
+
+ // Ignore the tag.
+ $this->parseError("Illegal closing tag at global scope.");
+
+ return;
+ }
+
+ // Special case handling for SVG.
+ if ($this->insertMode == static::IM_IN_SVG) {
+ $lname = Elements::normalizeSvgElement($lname);
+ }
+
+ // See https://github.com/facebook/hhvm/issues/2962
+ if (defined('HHVM_VERSION') && ($cid = $this->current->getAttribute('html5-php-fake-id-attribute'))) {
+ $this->current->removeAttribute('html5-php-fake-id-attribute');
+ } else {
+ $cid = spl_object_hash($this->current);
+ }
+
+ // XXX: Not sure whether we need this anymore.
+ // if ($name != $lname) {
+ // return $this->quirksTreeResolver($lname);
+ // }
+
+ // XXX: HTML has no parent. What do we do, though,
+ // if this element appears in the wrong place?
+ if ($lname == 'html') {
+ return;
+ }
+
+ // remove the namespaced definded by current node
+ if (isset($this->pushes[$cid])) {
+ for ($i = 0; $i < $this->pushes[$cid][0]; $i ++) {
+ array_shift($this->nsStack);
+ }
+ unset($this->pushes[$cid]);
+ }
+
+ if (! $this->autoclose($lname)) {
+ $this->parseError('Could not find closing tag for ' . $lname);
+ }
+
+ // switch ($this->insertMode) {
+ switch ($lname) {
+ case "head":
+ $this->insertMode = static::IM_AFTER_HEAD;
+ break;
+ case "body":
+ $this->insertMode = static::IM_AFTER_BODY;
+ break;
+ case "svg":
+ case "mathml":
+ $this->insertMode = static::IM_IN_BODY;
+ break;
+ }
+ }
+
+ public function comment($cdata)
+ {
+ // TODO: Need to handle case where comment appears outside of the HTML tag.
+ $node = $this->doc->createComment($cdata);
+ $this->current->appendChild($node);
+ }
+
+ public function text($data)
+ {
+ // XXX: Hmmm.... should we really be this strict?
+ if ($this->insertMode < static::IM_IN_HEAD) {
+ // Per '8.2.5.4.3 The "before head" insertion mode' the characters
+ // " \t\n\r\f" should be ignored but no mention of a parse error. This is
+ // practical as most documents contain these characters. Other text is not
+ // expected here so recording a parse error is necessary.
+ $dataTmp = trim($data, " \t\n\r\f");
+ if (! empty($dataTmp)) {
+ // fprintf(STDOUT, "Unexpected insert mode: %d", $this->insertMode);
+ $this->parseError("Unexpected text. Ignoring: " . $dataTmp);
+ }
+
+ return;
+ }
+ // fprintf(STDOUT, "Appending text %s.", $data);
+ $node = $this->doc->createTextNode($data);
+ $this->current->appendChild($node);
+ }
+
+ public function eof()
+ {
+ // If the $current isn't the $root, do we need to do anything?
+ }
+
+ public function parseError($msg, $line = 0, $col = 0)
+ {
+ $this->errors[] = sprintf("Line %d, Col %d: %s", $line, $col, $msg);
+ }
+
+ public function getErrors()
+ {
+ return $this->errors;
+ }
+
+ public function cdata($data)
+ {
+ $node = $this->doc->createCDATASection($data);
+ $this->current->appendChild($node);
+ }
+
+ public function processingInstruction($name, $data = null)
+ {
+ // XXX: Ignore initial XML declaration, per the spec.
+ if ($this->insertMode == static::IM_INITIAL && 'xml' == strtolower($name)) {
+ return;
+ }
+
+ // Important: The processor may modify the current DOM tree however
+ // it sees fit.
+ if (isset($this->processor)) {
+ $res = $this->processor->process($this->current, $name, $data);
+ if (! empty($res)) {
+ $this->current = $res;
+ }
+
+ return;
+ }
+
+ // Otherwise, this is just a dumb PI element.
+ $node = $this->doc->createProcessingInstruction($name, $data);
+
+ $this->current->appendChild($node);
+ }
+
+ // ==========================================================================
+ // UTILITIES
+ // ==========================================================================
+
+ /**
+ * Apply normalization rules to a tag name.
+ *
+ * See sections 2.9 and 8.1.2.
+ *
+ * @param string $name
+ * The tag name.
+ * @return string The normalized tag name.
+ */
+ protected function normalizeTagName($name)
+ {
+ /*
+ * Section 2.9 suggests that we should not do this. if (strpos($name, ':') !== false) { // We know from the grammar that there must be at least one other // char besides :, since : is not a legal tag start. $parts = explode(':', $name); return array_pop($parts); }
+ */
+ return $name;
+ }
+
+ protected function quirksTreeResolver($name)
+ {
+ throw new \Exception("Not implemented.");
+ }
+
+ /**
+ * Automatically climb the tree and close the closest node with the matching $tag.
+ */
+ protected function autoclose($tag)
+ {
+ $working = $this->current;
+ do {
+ if ($working->nodeType != XML_ELEMENT_NODE) {
+ return false;
+ }
+ if ($working->tagName == $tag) {
+ $this->current = $working->parentNode;
+
+ return true;
+ }
+ } while ($working = $working->parentNode);
+ return false;
+ }
+
+ /**
+ * Checks if the given tagname is an ancestor of the present candidate.
+ *
+ * If $this->current or anything above $this->current matches the given tag
+ * name, this returns true.
+ */
+ protected function isAncestor($tagname)
+ {
+ $candidate = $this->current;
+ while ($candidate->nodeType === XML_ELEMENT_NODE) {
+ if ($candidate->tagName == $tagname) {
+ return true;
+ }
+ $candidate = $candidate->parentNode;
+ }
+
+ return false;
+ }
+
+ /**
+ * Returns true if the immediate parent element is of the given tagname.
+ */
+ protected function isParent($tagname)
+ {
+ return $this->current->tagName == $tagname;
+ }
+}
\ No newline at end of file