summaryrefslogtreecommitdiff
path: root/lib/querypath/CssParser.php
diff options
context:
space:
mode:
Diffstat (limited to 'lib/querypath/CssParser.php')
-rw-r--r--lib/querypath/CssParser.php1108
1 files changed, 1108 insertions, 0 deletions
diff --git a/lib/querypath/CssParser.php b/lib/querypath/CssParser.php
new file mode 100644
index 0000000..2ef2802
--- /dev/null
+++ b/lib/querypath/CssParser.php
@@ -0,0 +1,1108 @@
+<?php
+/** @file
+ * CSS selector parsing classes.
+ *
+ * This file contains the tools necessary for parsing CSS 3 selectors.
+ * In the future it may be expanded to handle all of CSS 3.
+ *
+ * The parser contained herein is has an event-based API. Implementors should
+ * begin by implementing the {@link CssEventHandler} interface. For an example
+ * of how this is done, see {@link CssEventHandler.php}.
+ *
+ * @author M Butcher <matt@aleph-null.tv>
+ * @license http://opensource.org/licenses/lgpl-2.1.php The GNU Lesser GPL (LGPL) or an MIT-like license.
+ */
+
+/** @addtogroup querypath_css CSS Parsing
+ * QueryPath includes a CSS 3 Selector parser.
+ *
+ *
+ * Typically the parser is not accessed directly. Most developers will use it indirectly from
+ * qp(), htmlqp(), or one of the methods on a QueryPath object.
+ *
+ * This parser is modular and is not tied to QueryPath, so you can use it in your
+ * own (non-QueryPath) projects if you wish. To dive in, start with CssEventHandler, the
+ * event interface that works like a SAX API for CSS selectors. If you want to check out
+ * the details, check out the parser (CssParser), scanner (CssScanner), and token list (CssToken).
+ */
+
+require_once 'CssEventHandler.php';
+
+
+/**
+ * An event handler for handling CSS 3 Selector parsing.
+ *
+ * This provides a standard interface for CSS 3 Selector event handling. As the
+ * parser parses a selector, it will fire events. Implementations of CssEventHandler
+ * can then handle the events.
+ *
+ * This library is inspired by the SAX2 API for parsing XML. Each component of a
+ * selector fires an event, passing the necessary data on to the event handler.
+ *
+ * @ingroup querypath_css
+ */
+interface CssEventHandler {
+ /** The is-exactly (=) operator. */
+ const isExactly = 0; // =
+ /** The contains-with-space operator (~=). */
+ const containsWithSpace = 1; // ~=
+ /** The contains-with-hyphen operator (!=). */
+ const containsWithHyphen = 2; // |=
+ /** The contains-in-string operator (*=). */
+ const containsInString = 3; // *=
+ /** The begins-with operator (^=). */
+ const beginsWith = 4; // ^=
+ /** The ends-with operator ($=). */
+ const endsWith = 5; // $=
+ /** The any-element operator (*). */
+ const anyElement = '*';
+
+ /**
+ * This event is fired when a CSS ID is encountered.
+ * An ID begins with an octothorp: #name.
+ *
+ * @param string $id
+ * The ID passed in.
+ */
+ public function elementID($id); // #name
+ /**
+ * Handle an element name.
+ * Example: name
+ * @param string $name
+ * The name of the element.
+ */
+ public function element($name); // name
+ /**
+ * Handle a namespaced element name.
+ * example: namespace|name
+ * @param string $name
+ * The tag name.
+ * @param string $namespace
+ * The namespace identifier (Not the URI)
+ */
+ public function elementNS($name, $namespace = NULL);
+ /**
+ * Handle an any-element (*) operator.
+ * Example: *
+ */
+ public function anyElement(); // *
+ /**
+ * Handle an any-element operator that is constrained to a namespace.
+ * Example: ns|*
+ * @param string $ns
+ * The namespace identifier (not the URI).
+ */
+ public function anyElementInNS($ns); // ns|*
+ /**
+ * Handle a CSS class selector.
+ * Example: .name
+ * @param string $name
+ * The name of the class.
+ */
+ public function elementClass($name); // .name
+ /**
+ * Handle an attribute selector.
+ * Example: [name=attr]
+ * Example: [name~=attr]
+ * @param string $name
+ * The attribute name.
+ * @param string $value
+ * The value of the attribute, if given.
+ * @param int $operation
+ * The operation to be used for matching. See {@link CssEventHandler}
+ * constants for a list of supported operations.
+ */
+ public function attribute($name, $value = NULL, $operation = CssEventHandler::isExactly); // [name=attr]
+ /**
+ * Handle an attribute selector bound to a specific namespace.
+ * Example: [ns|name=attr]
+ * Example: [ns|name~=attr]
+ * @param string $name
+ * The attribute name.
+ * @param string $ns
+ * The namespace identifier (not the URI).
+ * @param string $value
+ * The value of the attribute, if given.
+ * @param int $operation
+ * The operation to be used for matching. See {@link CssEventHandler}
+ * constants for a list of supported operations.
+ */
+ public function attributeNS($name, $ns, $value = NULL, $operation = CssEventHandler::isExactly);
+ /**
+ * Handle a pseudo-class.
+ * Example: :name(value)
+ * @param string $name
+ * The pseudo-class name.
+ * @param string $value
+ * The value, if one is found.
+ */
+ public function pseudoClass($name, $value = NULL); //:name(value)
+ /**
+ * Handle a pseudo-element.
+ * Example: ::name
+ * @param string $name
+ * The pseudo-element name.
+ */
+ public function pseudoElement($name); // ::name
+ /**
+ * Handle a direct descendant combinator.
+ * Example: >
+ */
+ public function directDescendant(); // >
+ /**
+ * Handle a adjacent combinator.
+ * Example: +
+ */
+ public function adjacent(); // +
+ /**
+ * Handle an another-selector combinator.
+ * Example: ,
+ */
+ public function anotherSelector(); // ,
+ /**
+ * Handle a sibling combinator.
+ * Example: ~
+ */
+ public function sibling(); // ~ combinator
+ /**
+ * Handle an any-descendant combinator.
+ * Example: ' '
+ */
+ public function anyDescendant(); // ' ' (space) operator.
+
+}
+
+/**
+ * Tokens for CSS.
+ * This class defines the recognized tokens for the parser, and also
+ * provides utility functions for error reporting.
+ *
+ * @ingroup querypath_css
+ */
+final class CssToken {
+ const char = 0;
+ const star = 1;
+ const rangle = 2;
+ const dot = 3;
+ const octo = 4;
+ const rsquare = 5;
+ const lsquare = 6;
+ const colon = 7;
+ const rparen = 8;
+ const lparen = 9;
+ const plus = 10;
+ const tilde = 11;
+ const eq = 12;
+ const pipe = 13;
+ const comma = 14;
+ const white = 15;
+ const quote = 16;
+ const squote = 17;
+ const bslash = 18;
+ const carat = 19;
+ const dollar = 20;
+ const at = 21; // This is not in the spec. Apparently, old broken CSS uses it.
+
+ // In legal range for string.
+ const stringLegal = 99;
+
+ /**
+ * Get a name for a given constant. Used for error handling.
+ */
+ static function name($const_int) {
+ $a = array('character', 'star', 'right angle bracket',
+ 'dot', 'octothorp', 'right square bracket', 'left square bracket',
+ 'colon', 'right parenthesis', 'left parenthesis', 'plus', 'tilde',
+ 'equals', 'vertical bar', 'comma', 'space', 'quote', 'single quote',
+ 'backslash', 'carat', 'dollar', 'at');
+ if (isset($a[$const_int]) && is_numeric($const_int)) {
+ return $a[$const_int];
+ }
+ elseif ($const_int == 99) {
+ return 'a legal non-alphanumeric character';
+ }
+ elseif ($const_int == FALSE) {
+ return 'end of file';
+ }
+ return sprintf('illegal character (%s)', $const_int);
+ }
+}
+
+/**
+ * Parse a CSS selector.
+ *
+ * In CSS, a selector is used to identify which element or elements
+ * in a DOM are being selected for the application of a particular style.
+ * Effectively, selectors function as a query language for a structured
+ * document -- almost always HTML or XML.
+ *
+ * This class provides an event-based parser for CSS selectors. It can be
+ * used, for example, as a basis for writing a DOM query engine based on
+ * CSS.
+ *
+ * @ingroup querypath_css
+ */
+class CssParser {
+ protected $scanner = NULL;
+ protected $buffer = '';
+ protected $handler = NULL;
+ protected $strict = FALSE;
+
+ protected $DEBUG = FALSE;
+
+ /**
+ * Construct a new CSS parser object. This will attempt to
+ * parse the string as a CSS selector. As it parses, it will
+ * send events to the CssEventHandler implementation.
+ */
+ public function __construct($string, CssEventHandler $handler) {
+ $this->originalString = $string;
+ $is = new CssInputStream($string);
+ $this->scanner = new CssScanner($is);
+ $this->handler = $handler;
+ }
+
+ /**
+ * Parse the selector.
+ *
+ * This begins an event-based parsing process that will
+ * fire events as the selector is handled. A CssEventHandler
+ * implementation will be responsible for handling the events.
+ * @throws CssParseException
+ */
+ public function parse() {
+
+ $this->scanner->nextToken();
+ while ($this->scanner->token !== FALSE) {
+ // Primitive recursion detection.
+ $position = $this->scanner->position();
+
+ if ($this->DEBUG) {
+ print "PARSE " . $this->scanner->token. "\n";
+ }
+ $this->selector();
+
+ $finalPosition = $this->scanner->position();
+
+ if ($this->scanner->token !== FALSE && $finalPosition == $position) {
+ // If we get here, then the scanner did not pop a single character
+ // off of the input stream during a full run of the parser, which
+ // means that the current input does not match any recognizable
+ // pattern.
+ throw new CssParseException('CSS selector is not well formed.');
+ }
+
+ }
+
+ }
+
+ /**
+ * A restricted parser that can only parse simple selectors.
+ * The pseudoClass handler for this parser will throw an
+ * exception if it encounters a pseudo-element or the
+ * negation pseudo-class.
+ *
+ * @deprecated This is not used anywhere in QueryPath and
+ * may be removed.
+ *//*
+ public function parseSimpleSelector() {
+ while ($this->scanner->token !== FALSE) {
+ if ($this->DEBUG) print "SIMPLE SELECTOR\n";
+ $this->allElements();
+ $this->elementName();
+ $this->elementClass();
+ $this->elementID();
+ $this->pseudoClass(TRUE); // Operate in restricted mode.
+ $this->attribute();
+
+ // TODO: Need to add failure conditions here.
+ }
+ }*/
+
+ /**
+ * Handle an entire CSS selector.
+ */
+ private function selector() {
+ if ($this->DEBUG) print "SELECTOR{$this->scanner->position()}\n";
+ $this->consumeWhitespace(); // Remove leading whitespace
+ $this->simpleSelectors();
+ $this->combinator();
+ }
+
+ /**
+ * Consume whitespace and return a count of the number of whitespace consumed.
+ */
+ private function consumeWhitespace() {
+ if ($this->DEBUG) print "CONSUME WHITESPACE\n";
+ $white = 0;
+ while ($this->scanner->token == CssToken::white) {
+ $this->scanner->nextToken();
+ ++$white;
+ }
+ return $white;
+ }
+
+ /**
+ * Handle one of the five combinators: '>', '+', ' ', '~', and ','.
+ * This will call the appropriate event handlers.
+ * @see CssEventHandler::directDescendant(),
+ * @see CssEventHandler::adjacent(),
+ * @see CssEventHandler::anyDescendant(),
+ * @see CssEventHandler::anotherSelector().
+ */
+ private function combinator() {
+ if ($this->DEBUG) print "COMBINATOR\n";
+ /*
+ * Problem: ' ' and ' > ' are both valid combinators.
+ * So we have to track whitespace consumption to see
+ * if we are hitting the ' ' combinator or if the
+ * selector just has whitespace padding another combinator.
+ */
+
+ // Flag to indicate that post-checks need doing
+ $inCombinator = FALSE;
+ $white = $this->consumeWhitespace();
+ $t = $this->scanner->token;
+
+ if ($t == CssToken::rangle) {
+ $this->handler->directDescendant();
+ $this->scanner->nextToken();
+ $inCombinator = TRUE;
+ //$this->simpleSelectors();
+ }
+ elseif ($t == CssToken::plus) {
+ $this->handler->adjacent();
+ $this->scanner->nextToken();
+ $inCombinator = TRUE;
+ //$this->simpleSelectors();
+ }
+ elseif ($t == CssToken::comma) {
+ $this->handler->anotherSelector();
+ $this->scanner->nextToken();
+ $inCombinator = TRUE;
+ //$this->scanner->selectors();
+ }
+ elseif ($t == CssToken::tilde) {
+ $this->handler->sibling();
+ $this->scanner->nextToken();
+ $inCombinator = TRUE;
+ }
+
+ // Check that we don't get two combinators in a row.
+ if ($inCombinator) {
+ $white = 0;
+ if ($this->DEBUG) print "COMBINATOR: " . CssToken::name($t) . "\n";
+ $this->consumeWhitespace();
+ if ($this->isCombinator($this->scanner->token)) {
+ throw new CssParseException("Illegal combinator: Cannot have two combinators in sequence.");
+ }
+ }
+ // Check to see if we have whitespace combinator:
+ elseif ($white > 0) {
+ if ($this->DEBUG) print "COMBINATOR: any descendant\n";
+ $inCombinator = TRUE;
+ $this->handler->anyDescendant();
+ }
+ else {
+ if ($this->DEBUG) print "COMBINATOR: no combinator found.\n";
+ }
+ }
+
+ /**
+ * Check if the token is a combinator.
+ */
+ private function isCombinator($tok) {
+ $combinators = array(CssToken::plus, CssToken::rangle, CssToken::comma, CssToken::tilde);
+ return in_array($tok, $combinators);
+ }
+
+ /**
+ * Handle a simple selector.
+ */
+ private function simpleSelectors() {
+ if ($this->DEBUG) print "SIMPLE SELECTOR\n";
+ $this->allElements();
+ $this->elementName();
+ $this->elementClass();
+ $this->elementID();
+ $this->pseudoClass();
+ $this->attribute();
+ }
+
+ /**
+ * Handles CSS ID selectors.
+ * This will call CssEventHandler::elementID().
+ */
+ private function elementID() {
+ if ($this->DEBUG) print "ELEMENT ID\n";
+ if ($this->scanner->token == CssToken::octo) {
+ $this->scanner->nextToken();
+ if ($this->scanner->token !== CssToken::char) {
+ throw new CssParseException("Expected string after #");
+ }
+ $id = $this->scanner->getNameString();
+ $this->handler->elementID($id);
+ }
+ }
+
+ /**
+ * Handles CSS class selectors.
+ * This will call the CssEventHandler::elementClass() method.
+ */
+ private function elementClass() {
+ if ($this->DEBUG) print "ELEMENT CLASS\n";
+ if ($this->scanner->token == CssToken::dot) {
+ $this->scanner->nextToken();
+ $this->consumeWhitespace(); // We're very fault tolerent. This should prob through error.
+ $cssClass = $this->scanner->getNameString();
+ $this->handler->elementClass($cssClass);
+ }
+ }
+
+ /**
+ * Handle a pseudo-class and pseudo-element.
+ *
+ * CSS 3 selectors support separate pseudo-elements, using :: instead
+ * of : for separator. This is now supported, and calls the pseudoElement
+ * handler, CssEventHandler::pseudoElement().
+ *
+ * This will call CssEventHandler::pseudoClass() when a
+ * pseudo-class is parsed.
+ */
+ private function pseudoClass($restricted = FALSE) {
+ if ($this->DEBUG) print "PSEUDO-CLASS\n";
+ if ($this->scanner->token == CssToken::colon) {
+
+ // Check for CSS 3 pseudo element:
+ $isPseudoElement = FALSE;
+ if ($this->scanner->nextToken() === CssToken::colon) {
+ $isPseudoElement = TRUE;
+ $this->scanner->nextToken();
+ }
+
+ $name = $this->scanner->getNameString();
+ if ($restricted && $name == 'not') {
+ throw new CssParseException("The 'not' pseudo-class is illegal in this context.");
+ }
+
+ $value = NULL;
+ if ($this->scanner->token == CssToken::lparen) {
+ if ($isPseudoElement) {
+ throw new CssParseException("Illegal left paren. Pseudo-Element cannot have arguments.");
+ }
+ $value = $this->pseudoClassValue();
+ }
+
+ // FIXME: This should throw errors when pseudo element has values.
+ if ($isPseudoElement) {
+ if ($restricted) {
+ throw new CssParseException("Pseudo-Elements are illegal in this context.");
+ }
+ $this->handler->pseudoElement($name);
+ $this->consumeWhitespace();
+
+ // Per the spec, pseudo-elements must be the last items in a selector, so we
+ // check to make sure that we are either at the end of the stream or that a
+ // new selector is starting. Only one pseudo-element is allowed per selector.
+ if ($this->scanner->token !== FALSE && $this->scanner->token !== CssToken::comma) {
+ throw new CssParseException("A Pseudo-Element must be the last item in a selector.");
+ }
+ }
+ else {
+ $this->handler->pseudoClass($name, $value);
+ }
+ }
+ }
+
+ /**
+ * Get the value of a pseudo-classes.
+ *
+ * @return string
+ * Returns the value found from a pseudo-class.
+ *
+ * @todo Pseudoclasses can be passed pseudo-elements and
+ * other pseudo-classes as values, which means :pseudo(::pseudo)
+ * is legal.
+ */
+ private function pseudoClassValue() {
+ if ($this->scanner->token == CssToken::lparen) {
+ $buf = '';
+
+ // For now, just leave pseudoClass value vague.
+ /*
+ // We have to peek to see if next char is a colon because
+ // pseudo-classes and pseudo-elements are legal strings here.
+ print $this->scanner->peek();
+ if ($this->scanner->peek() == ':') {
+ print "Is pseudo\n";
+ $this->scanner->nextToken();
+
+ // Pseudo class
+ if ($this->scanner->token == CssToken::colon) {
+ $buf .= ':';
+ $this->scanner->nextToken();
+ // Pseudo element
+ if ($this->scanner->token == CssToken::colon) {
+ $buf .= ':';
+ $this->scanner->nextToken();
+ }
+ // Ident
+ $buf .= $this->scanner->getNameString();
+ }
+ }
+ else {
+ print "fetching string.\n";
+ $buf .= $this->scanner->getQuotedString();
+ if ($this->scanner->token != CssToken::rparen) {
+ $this->throwError(CssToken::rparen, $this->scanner->token);
+ }
+ $this->scanner->nextToken();
+ }
+ return $buf;
+ */
+ $buf .= $this->scanner->getQuotedString();
+ return $buf;
+ }
+ }
+
+ /**
+ * Handle element names.
+ * This will call the CssEventHandler::elementName().
+ *
+ * This handles:
+ * <code>
+ * name (CssEventHandler::element())
+ * |name (CssEventHandler::element())
+ * ns|name (CssEventHandler::elementNS())
+ * ns|* (CssEventHandler::elementNS())
+ * </code>
+ */
+ private function elementName() {
+ if ($this->DEBUG) print "ELEMENT NAME\n";
+ if ($this->scanner->token === CssToken::pipe) {
+ // We have '|name', which is equiv to 'name'
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+ $elementName = $this->scanner->getNameString();
+ $this->handler->element($elementName);
+ }
+ elseif ($this->scanner->token === CssToken::char) {
+ $elementName = $this->scanner->getNameString();
+ if ($this->scanner->token == CssToken::pipe) {
+ // Get ns|name
+ $elementNS = $elementName;
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+ if ($this->scanner->token === CssToken::star) {
+ // We have ns|*
+ $this->handler->anyElementInNS($elementNS);
+ $this->scanner->nextToken();
+ }
+ elseif ($this->scanner->token !== CssToken::char) {
+ $this->throwError(CssToken::char, $this->scanner->token);
+ }
+ else {
+ $elementName = $this->scanner->getNameString();
+ // We have ns|name
+ $this->handler->elementNS($elementName, $elementNS);
+ }
+
+ }
+ else {
+ $this->handler->element($elementName);
+ }
+ }
+ }
+
+ /**
+ * Check for all elements designators. Due to the new CSS 3 namespace
+ * support, this is slightly more complicated, now, as it handles
+ * the *|name and *|* cases as well as *.
+ *
+ * Calls CssEventHandler::anyElement() or CssEventHandler::elementName().
+ */
+ private function allElements() {
+ if ($this->scanner->token === CssToken::star) {
+ $this->scanner->nextToken();
+ if ($this->scanner->token === CssToken::pipe) {
+ $this->scanner->nextToken();
+ if ($this->scanner->token === CssToken::star) {
+ // We got *|*. According to spec, this requires
+ // that the element has a namespace, so we pass it on
+ // to the handler:
+ $this->scanner->nextToken();
+ $this->handler->anyElementInNS('*');
+ }
+ else {
+ // We got *|name, which means the name MUST be in a namespce,
+ // so we pass this off to elementNameNS().
+ $name = $this->scanner->getNameString();
+ $this->handler->elementNS($name, '*');
+ }
+ }
+ else {
+ $this->handler->anyElement();
+ }
+ }
+ }
+
+ /**
+ * Handler an attribute.
+ * An attribute can be in one of two forms:
+ * <code>[attrName]</code>
+ * or
+ * <code>[attrName="AttrValue"]</code>
+ *
+ * This may call the following event handlers: CssEventHandler::attribute().
+ */
+ private function attribute() {
+ if($this->scanner->token == CssToken::lsquare) {
+ $attrVal = $op = $ns = NULL;
+
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+
+ if ($this->scanner->token === CssToken::at) {
+ if ($this->strict) {
+ throw new CssParseException('The @ is illegal in attributes.');
+ }
+ else {
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+ }
+ }
+
+ if ($this->scanner->token === CssToken::star) {
+ // Global namespace... requires that attr be prefixed,
+ // so we pass this on to a namespace handler.
+ $ns = '*';
+ $this->scanner->nextToken();
+ }
+ if ($this->scanner->token === CssToken::pipe) {
+ // Skip this. It's a global namespace.
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+ }
+
+ $attrName = $this->scanner->getNameString();
+ $this->consumeWhitespace();
+
+ // Check for namespace attribute: ns|attr. We have to peek() to make
+ // sure that we haven't hit the |= operator, which looks the same.
+ if ($this->scanner->token === CssToken::pipe && $this->scanner->peek() !== '=') {
+ // We have a namespaced attribute.
+ $ns = $attrName;
+ $this->scanner->nextToken();
+ $attrName = $this->scanner->getNameString();
+ $this->consumeWhitespace();
+ }
+
+ // Note: We require that operators do not have spaces
+ // between characters, e.g. ~= , not ~ =.
+
+ // Get the operator:
+ switch ($this->scanner->token) {
+ case CssToken::eq:
+ $this->consumeWhitespace();
+ $op = CssEventHandler::isExactly;
+ break;
+ case CssToken::tilde:
+ if ($this->scanner->nextToken() !== CssToken::eq) {
+ $this->throwError(CssToken::eq, $this->scanner->token);
+ }
+ $op = CssEventHandler::containsWithSpace;
+ break;
+ case CssToken::pipe:
+ if ($this->scanner->nextToken() !== CssToken::eq) {
+ $this->throwError(CssToken::eq, $this->scanner->token);
+ }
+ $op = CssEventHandler::containsWithHyphen;
+ break;
+ case CssToken::star:
+ if ($this->scanner->nextToken() !== CssToken::eq) {
+ $this->throwError(CssToken::eq, $this->scanner->token);
+ }
+ $op = CssEventHandler::containsInString;
+ break;
+ case CssToken::dollar;
+ if ($this->scanner->nextToken() !== CssToken::eq) {
+ $this->throwError(CssToken::eq, $this->scanner->token);
+ }
+ $op = CssEventHandler::endsWith;
+ break;
+ case CssToken::carat:
+ if ($this->scanner->nextToken() !== CssToken::eq) {
+ $this->throwError(CssToken::eq, $this->scanner->token);
+ }
+ $op = CssEventHandler::beginsWith;
+ break;
+ }
+
+ if (isset($op)) {
+ // Consume '=' and go on.
+ $this->scanner->nextToken();
+ $this->consumeWhitespace();
+
+ // So... here we have a problem. The grammer suggests that the
+ // value here is String1 or String2, both of which are enclosed
+ // in quotes of some sort, and both of which allow lots of special
+ // characters. But the spec itself includes examples like this:
+ // [lang=fr]
+ // So some bareword support is assumed. To get around this, we assume
+ // that bare words follow the NAME rules, while quoted strings follow
+ // the String1/String2 rules.
+
+ if ($this->scanner->token === CssToken::quote || $this->scanner->token === CssToken::squote) {
+ $attrVal = $this->scanner->getQuotedString();
+ }
+ else {
+ $attrVal = $this->scanner->getNameString();
+ }
+
+ if ($this->DEBUG) {
+ print "ATTR: $attrVal AND OP: $op\n";
+ }
+ }
+
+ $this->consumeWhitespace();
+
+ if ($this->scanner->token != CssToken::rsquare) {
+ $this->throwError(CssToken::rsquare, $this->scanner->token);
+ }
+
+ if (isset($ns)) {
+ $this->handler->attributeNS($attrName, $ns, $attrVal, $op);
+ }
+ elseif (isset($attrVal)) {
+ $this->handler->attribute($attrName, $attrVal, $op);
+ }
+ else {
+ $this->handler->attribute($attrName);
+ }
+ $this->scanner->nextToken();
+ }
+ }
+
+ /**
+ * Utility for throwing a consistantly-formatted parse error.
+ */
+ private function throwError($expected, $got) {
+ $filter = sprintf('Expected %s, got %s', CssToken::name($expected), CssToken::name($got));
+ throw new CssParseException($filter);
+ }
+
+}
+
+/**
+ * Scanner for CSS selector parsing.
+ *
+ * This provides a simple scanner for traversing an input stream.
+ *
+ * @ingroup querypath_css
+ */
+final class CssScanner {
+ var $is = NULL;
+ public $value = NULL;
+ public $token = NULL;
+
+ var $recurse = FALSE;
+ var $it = 0;
+
+ /**
+ * Given a new input stream, tokenize the CSS selector string.
+ * @see CssInputStream
+ * @param CssInputStream $in
+ * An input stream to be scanned.
+ */
+ public function __construct(CssInputStream $in) {
+ $this->is = $in;
+ }
+
+ /**
+ * Return the position of the reader in the string.
+ */
+ public function position() {
+ return $this->is->position;
+ }
+
+ /**
+ * See the next char without removing it from the stack.
+ *
+ * @return char
+ * Returns the next character on the stack.
+ */
+ public function peek() {
+ return $this->is->peek();
+ }
+
+ /**
+ * Get the next token in the input stream.
+ *
+ * This sets the current token to the value of the next token in
+ * the stream.
+ *
+ * @return int
+ * Returns an int value corresponding to one of the CssToken constants,
+ * or FALSE if the end of the string is reached. (Remember to use
+ * strong equality checking on FALSE, since 0 is a valid token id.)
+ */
+ public function nextToken() {
+ $tok = -1;
+ ++$this->it;
+ if ($this->is->isEmpty()) {
+ if ($this->recurse) {
+ throw new Exception("Recursion error detected at iteration " . $this->it . '.');
+ exit();
+ }
+ //print "{$this->it}: All done\n";
+ $this->recurse = TRUE;
+ $this->token = FALSE;
+ return FALSE;
+ }
+ $ch = $this->is->consume();
+ //print __FUNCTION__ . " Testing $ch.\n";
+ if (ctype_space($ch)) {
+ $this->value = ' '; // Collapse all WS to a space.
+ $this->token = $tok = CssToken::white;
+ //$ch = $this->is->consume();
+ return $tok;
+ }
+
+ if (ctype_alnum($ch) || $ch == '-' || $ch == '_') {
+ // It's a character
+ $this->value = $ch; //strtolower($ch);
+ $this->token = $tok = CssToken::char;
+ return $tok;
+ }
+
+ $this->value = $ch;
+
+ switch($ch) {
+ case '*':
+ $tok = CssToken::star;
+ break;
+ case chr(ord('>')):
+ $tok = CssToken::rangle;
+ break;
+ case '.':
+ $tok = CssToken::dot;
+ break;
+ case '#':
+ $tok = CssToken::octo;
+ break;
+ case '[':
+ $tok = CssToken::lsquare;
+ break;
+ case ']':
+ $tok = CssToken::rsquare;
+ break;
+ case ':':
+ $tok = CssToken::colon;
+ break;
+ case '(':
+ $tok = CssToken::lparen;
+ break;
+ case ')':
+ $tok = CssToken::rparen;
+ break;
+ case '+':
+ $tok = CssToken::plus;
+ break;
+ case '~':
+ $tok = CssToken::tilde;
+ break;
+ case '=':
+ $tok = CssToken::eq;
+ break;
+ case '|':
+ $tok = CssToken::pipe;
+ break;
+ case ',':
+ $tok = CssToken::comma;
+ break;
+ case chr(34):
+ $tok = CssToken::quote;
+ break;
+ case "'":
+ $tok = CssToken::squote;
+ break;
+ case '\\':
+ $tok = CssToken::bslash;
+ break;
+ case '^':
+ $tok = CssToken::carat;
+ break;
+ case '$':
+ $tok = CssToken::dollar;
+ break;
+ case '@':
+ $tok = CssToken::at;
+ break;
+ }
+
+
+ // Catch all characters that are legal within strings.
+ if ($tok == -1) {
+ // TODO: This should be UTF-8 compatible, but PHP doesn't
+ // have a native UTF-8 string. Should we use external
+ // mbstring library?
+
+ $ord = ord($ch);
+ // Characters in this pool are legal for use inside of
+ // certain strings. Extended ASCII is used here, though I
+ // Don't know if these are really legal.
+ if (($ord >= 32 && $ord <= 126) || ($ord >= 128 && $ord <= 255)) {
+ $tok = CssToken::stringLegal;
+ }
+ else {
+ throw new CSSParseException('Illegal character found in stream: ' . $ord);
+ }
+ }
+
+ $this->token = $tok;
+ return $tok;
+ }
+
+ /**
+ * Get a name string from the input stream.
+ * A name string must be composed of
+ * only characters defined in CssToken:char: -_a-zA-Z0-9
+ */
+ public function getNameString() {
+ $buf = '';
+ while ($this->token === CssToken::char) {
+ $buf .= $this->value;
+ $this->nextToken();
+ //print '_';
+ }
+ return $buf;
+ }
+
+ /**
+ * This gets a string with any legal 'string' characters.
+ * See CSS Selectors specification, section 11, for the
+ * definition of string.
+ *
+ * This will check for string1, string2, and the case where a
+ * string is unquoted (Oddly absent from the "official" grammar,
+ * though such strings are present as examples in the spec.)
+ *
+ * Note:
+ * Though the grammar supplied by CSS 3 Selectors section 11 does not
+ * address the contents of a pseudo-class value, the spec itself indicates
+ * that a pseudo-class value is a "value between parenthesis" [6.6]. The
+ * examples given use URLs among other things, making them closer to the
+ * definition of 'string' than to 'name'. So we handle them here as strings.
+ */
+ public function getQuotedString() {
+ if ($this->token == CssToken::quote || $this->token == CssToken::squote || $this->token == CssToken::lparen) {
+ $end = ($this->token == CssToken::lparen) ? CssToken::rparen : $this->token;
+ $buf = '';
+ $escape = FALSE;
+
+ $this->nextToken(); // Skip the opening quote/paren
+
+ // The second conjunct is probably not necessary.
+ while ($this->token !== FALSE && $this->token > -1) {
+ //print "Char: $this->value \n";
+ if ($this->token == CssToken::bslash && !$escape) {
+ // XXX: The backslash (\) is removed here.
+ // Turn on escaping.
+ //$buf .= $this->value;
+ $escape = TRUE;
+ }
+ elseif ($escape) {
+ // Turn off escaping
+ $buf .= $this->value;
+ $escape = FALSE;
+ }
+ elseif ($this->token === $end) {
+ // At end of string; skip token and break.
+ $this->nextToken();
+ break;
+ }
+ else {
+ // Append char.
+ $buf .= $this->value;
+ }
+ $this->nextToken();
+ }
+ return $buf;
+ }
+ }
+
+ /**
+ * Get a string from the input stream.
+ * This is a convenience function for getting a string of
+ * characters that are either alphanumber or whitespace. See
+ * the CssToken::white and CssToken::char definitions.
+ *
+ * @deprecated This is not used anywhere in QueryPath.
+ *//*
+ public function getStringPlusWhitespace() {
+ $buf = '';
+ if($this->token === FALSE) {return '';}
+ while ($this->token === CssToken::char || $this->token == CssToken::white) {
+ $buf .= $this->value;
+ $this->nextToken();
+ }
+ return $buf;
+ }*/
+
+}
+
+/**
+ * Simple wrapper to turn a string into an input stream.
+ * This provides a standard interface on top of an array of
+ * characters.
+ */
+class CssInputStream {
+ protected $stream = NULL;
+ public $position = 0;
+ /**
+ * Build a new CSS input stream from a string.
+ *
+ * @param string
+ * String to turn into an input stream.
+ */
+ function __construct($string) {
+ $this->stream = str_split($string);
+ }
+ /**
+ * Look ahead one character.
+ *
+ * @return char
+ * Returns the next character, but does not remove it from
+ * the stream.
+ */
+ function peek() {
+ return $this->stream[0];
+ }
+ /**
+ * Get the next unconsumed character in the stream.
+ * This will remove that character from the front of the
+ * stream and return it.
+ */
+ function consume() {
+ $ret = array_shift($this->stream);
+ if (!empty($ret)) {
+ $this->position++;
+ }
+ return $ret;
+ }
+ /**
+ * Check if the stream is empty.
+ * @return boolean
+ * Returns TRUE when the stream is empty, FALSE otherwise.
+ */
+ function isEmpty() {
+ return count($this->stream) == 0;
+ }
+}
+
+/**
+ * Exception indicating an error in CSS parsing.
+ *
+ * @ingroup querypath_css
+ */
+class CSSParseException extends EXCEPTION {} \ No newline at end of file
generated by cgit v1.2.3 (git 2.46.0) at 2025-02-23 05:09:21 +0000