/testing/selenium-core/xpath/xpath.js
JavaScript | 2450 lines | 1776 code | 354 blank | 320 comment | 441 complexity | 380ca59ea83ca2115ebf3101c89cd4b5 MD5 | raw file
Possible License(s): Apache-2.0
- // Copyright 2005 Google Inc.
- // All Rights Reserved
- //
- // An XPath parser and evaluator written in JavaScript. The
- // implementation is complete except for functions handling
- // namespaces.
- //
- // Reference: [XPATH] XPath Specification
- // <http://www.w3.org/TR/1999/REC-xpath-19991116>.
- //
- //
- // The API of the parser has several parts:
- //
- // 1. The parser function xpathParse() that takes a string and returns
- // an expession object.
- //
- // 2. The expression object that has an evaluate() method to evaluate the
- // XPath expression it represents. (It is actually a hierarchy of
- // objects that resembles the parse tree, but an application will call
- // evaluate() only on the top node of this hierarchy.)
- //
- // 3. The context object that is passed as an argument to the evaluate()
- // method, which represents the DOM context in which the expression is
- // evaluated.
- //
- // 4. The value object that is returned from evaluate() and represents
- // values of the different types that are defined by XPath (number,
- // string, boolean, and node-set), and allows to convert between them.
- //
- // These parts are near the top of the file, the functions and data
- // that are used internally follow after them.
- //
- //
- // Author: Steffen Meschkat <mesch@google.com>
- // The entry point for the parser.
- //
- // @param expr a string that contains an XPath expression.
- // @return an expression object that can be evaluated with an
- // expression context.
- function xpathParse(expr) {
- xpathLog('parse ' + expr);
- xpathParseInit();
- var cached = xpathCacheLookup(expr);
- if (cached) {
- xpathLog(' ... cached');
- return cached;
- }
- // Optimize for a few common cases: simple attribute node tests
- // (@id), simple element node tests (page), variable references
- // ($address), numbers (4), multi-step path expressions where each
- // step is a plain element node test
- // (page/overlay/locations/location).
- if (expr.match(/^(\$|@)?\w+$/i)) {
- var ret = makeSimpleExpr(expr);
- xpathParseCache[expr] = ret;
- xpathLog(' ... simple');
- return ret;
- }
- if (expr.match(/^\w+(\/\w+)*$/i)) {
- var ret = makeSimpleExpr2(expr);
- xpathParseCache[expr] = ret;
- xpathLog(' ... simple 2');
- return ret;
- }
- var cachekey = expr; // expr is modified during parse
- var stack = [];
- var ahead = null;
- var previous = null;
- var done = false;
- var parse_count = 0;
- var lexer_count = 0;
- var reduce_count = 0;
- while (!done) {
- parse_count++;
- expr = expr.replace(/^\s*/, '');
- previous = ahead;
- ahead = null;
- var rule = null;
- var match = '';
- for (var i = 0; i < xpathTokenRules.length; ++i) {
- var result = xpathTokenRules[i].re.exec(expr);
- lexer_count++;
- if (result && result.length > 0 && result[0].length > match.length) {
- rule = xpathTokenRules[i];
- match = result[0];
- break;
- }
- }
- // Special case: allow operator keywords to be element and
- // variable names.
- // NOTE(mesch): The parser resolves conflicts by looking ahead,
- // and this is the only case where we look back to
- // disambiguate. So this is indeed something different, and
- // looking back is usually done in the lexer (via states in the
- // general case, called "start conditions" in flex(1)). Also,the
- // conflict resolution in the parser is not as robust as it could
- // be, so I'd like to keep as much off the parser as possible (all
- // these precedence values should be computed from the grammar
- // rules and possibly associativity declarations, as in bison(1),
- // and not explicitly set.
- if (rule &&
- (rule == TOK_DIV ||
- rule == TOK_MOD ||
- rule == TOK_AND ||
- rule == TOK_OR) &&
- (!previous ||
- previous.tag == TOK_AT ||
- previous.tag == TOK_DSLASH ||
- previous.tag == TOK_SLASH ||
- previous.tag == TOK_AXIS ||
- previous.tag == TOK_DOLLAR)) {
- rule = TOK_QNAME;
- }
- if (rule) {
- expr = expr.substr(match.length);
- xpathLog('token: ' + match + ' -- ' + rule.label);
- ahead = {
- tag: rule,
- match: match,
- prec: rule.prec ? rule.prec : 0, // || 0 is removed by the compiler
- expr: makeTokenExpr(match)
- };
- } else {
- xpathLog('DONE');
- done = true;
- }
- while (xpathReduce(stack, ahead)) {
- reduce_count++;
- xpathLog('stack: ' + stackToString(stack));
- }
- }
- xpathLog('stack: ' + stackToString(stack));
- // DGF any valid XPath should "reduce" to a single Expr token
- if (stack.length != 1) {
- throw 'XPath parse error ' + cachekey + ':\n' + stackToString(stack);
- }
- var result = stack[0].expr;
- xpathParseCache[cachekey] = result;
- xpathLog('XPath parse: ' + parse_count + ' / ' +
- lexer_count + ' / ' + reduce_count);
- return result;
- }
- var xpathParseCache = {};
- function xpathCacheLookup(expr) {
- return xpathParseCache[expr];
- }
- /*DGF xpathReduce is where the magic happens in this parser.
- Skim down to the bottom of this file to find the table of
- grammatical rules and precedence numbers, "The productions of the grammar".
- The idea here
- is that we want to take a stack of tokens and apply
- grammatical rules to them, "reducing" them to higher-level
- tokens. Ultimately, any valid XPath should reduce to exactly one
- "Expr" token.
- Reduce too early or too late and you'll have two tokens that can't reduce
- to single Expr. For example, you may hastily reduce a qname that
- should name a function, incorrectly treating it as a tag name.
- Or you may reduce too late, accidentally reducing the last part of the
- XPath into a top-level "Expr" that won't reduce with earlier parts of
- the XPath.
- A "cand" is a grammatical rule candidate, with a given precedence
- number. "ahead" is the upcoming token, which also has a precedence
- number. If the token has a higher precedence number than
- the rule candidate, we'll "shift" the token onto the token stack,
- instead of immediately applying the rule candidate.
- Some tokens have left associativity, in which case we shift when they
- have LOWER precedence than the candidate.
- */
- function xpathReduce(stack, ahead) {
- var cand = null;
- if (stack.length > 0) {
- var top = stack[stack.length-1];
- var ruleset = xpathRules[top.tag.key];
- if (ruleset) {
- for (var i = 0; i < ruleset.length; ++i) {
- var rule = ruleset[i];
- var match = xpathMatchStack(stack, rule[1]);
- if (match.length) {
- cand = {
- tag: rule[0],
- rule: rule,
- match: match
- };
- cand.prec = xpathGrammarPrecedence(cand);
- break;
- }
- }
- }
- }
- var ret;
- if (cand && (!ahead || cand.prec > ahead.prec ||
- (ahead.tag.left && cand.prec >= ahead.prec))) {
- for (var i = 0; i < cand.match.matchlength; ++i) {
- stack.pop();
- }
- xpathLog('reduce ' + cand.tag.label + ' ' + cand.prec +
- ' ahead ' + (ahead ? ahead.tag.label + ' ' + ahead.prec +
- (ahead.tag.left ? ' left' : '')
- : ' none '));
- var matchexpr = mapExpr(cand.match, function(m) { return m.expr; });
- xpathLog('going to apply ' + cand.rule[3].toString());
- cand.expr = cand.rule[3].apply(null, matchexpr);
- stack.push(cand);
- ret = true;
- } else {
- if (ahead) {
- xpathLog('shift ' + ahead.tag.label + ' ' + ahead.prec +
- (ahead.tag.left ? ' left' : '') +
- ' over ' + (cand ? cand.tag.label + ' ' +
- cand.prec : ' none'));
- stack.push(ahead);
- }
- ret = false;
- }
- return ret;
- }
- function xpathMatchStack(stack, pattern) {
- // NOTE(mesch): The stack matches for variable cardinality are
- // greedy but don't do backtracking. This would be an issue only
- // with rules of the form A* A, i.e. with an element with variable
- // cardinality followed by the same element. Since that doesn't
- // occur in the grammar at hand, all matches on the stack are
- // unambiguous.
- var S = stack.length;
- var P = pattern.length;
- var p, s;
- var match = [];
- match.matchlength = 0;
- var ds = 0;
- for (p = P - 1, s = S - 1; p >= 0 && s >= 0; --p, s -= ds) {
- ds = 0;
- var qmatch = [];
- if (pattern[p] == Q_MM) {
- p -= 1;
- match.push(qmatch);
- while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
- qmatch.push(stack[s - ds]);
- ds += 1;
- match.matchlength += 1;
- }
- } else if (pattern[p] == Q_01) {
- p -= 1;
- match.push(qmatch);
- while (s - ds >= 0 && ds < 2 && stack[s - ds].tag == pattern[p]) {
- qmatch.push(stack[s - ds]);
- ds += 1;
- match.matchlength += 1;
- }
- } else if (pattern[p] == Q_1M) {
- p -= 1;
- match.push(qmatch);
- if (stack[s].tag == pattern[p]) {
- while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
- qmatch.push(stack[s - ds]);
- ds += 1;
- match.matchlength += 1;
- }
- } else {
- return [];
- }
- } else if (stack[s].tag == pattern[p]) {
- match.push(stack[s]);
- ds += 1;
- match.matchlength += 1;
- } else {
- return [];
- }
- reverseInplace(qmatch);
- qmatch.expr = mapExpr(qmatch, function(m) { return m.expr; });
- }
- reverseInplace(match);
- if (p == -1) {
- return match;
- } else {
- return [];
- }
- }
- function xpathTokenPrecedence(tag) {
- return tag.prec || 2;
- }
- function xpathGrammarPrecedence(frame) {
- var ret = 0;
- if (frame.rule) { /* normal reduce */
- if (frame.rule.length >= 3 && frame.rule[2] >= 0) {
- ret = frame.rule[2];
- } else {
- for (var i = 0; i < frame.rule[1].length; ++i) {
- var p = xpathTokenPrecedence(frame.rule[1][i]);
- ret = Math.max(ret, p);
- }
- }
- } else if (frame.tag) { /* TOKEN match */
- ret = xpathTokenPrecedence(frame.tag);
- } else if (frame.length) { /* Q_ match */
- for (var j = 0; j < frame.length; ++j) {
- var p = xpathGrammarPrecedence(frame[j]);
- ret = Math.max(ret, p);
- }
- }
- return ret;
- }
- function stackToString(stack) {
- var ret = '';
- for (var i = 0; i < stack.length; ++i) {
- if (ret) {
- ret += '\n';
- }
- ret += stack[i].tag.label;
- }
- return ret;
- }
- // XPath expression evaluation context. An XPath context consists of a
- // DOM node, a list of DOM nodes that contains this node, a number
- // that represents the position of the single node in the list, and a
- // current set of variable bindings. (See XPath spec.)
- //
- // The interface of the expression context:
- //
- // Constructor -- gets the node, its position, the node set it
- // belongs to, and a parent context as arguments. The parent context
- // is used to implement scoping rules for variables: if a variable
- // is not found in the current context, it is looked for in the
- // parent context, recursively. Except for node, all arguments have
- // default values: default position is 0, default node set is the
- // set that contains only the node, and the default parent is null.
- //
- // Notice that position starts at 0 at the outside interface;
- // inside XPath expressions this shows up as position()=1.
- //
- // clone() -- creates a new context with the current context as
- // parent. If passed as argument to clone(), the new context has a
- // different node, position, or node set. What is not passed is
- // inherited from the cloned context.
- //
- // setVariable(name, expr) -- binds given XPath expression to the
- // name.
- //
- // getVariable(name) -- what the name says.
- //
- // setNode(position) -- sets the context to the node at the given
- // position. Needed to implement scoping rules for variables in
- // XPath. (A variable is visible to all subsequent siblings, not
- // only to its children.)
- //
- // set/isCaseInsensitive -- specifies whether node name tests should
- // be case sensitive. If you're executing xpaths against a regular
- // HTML DOM, you probably don't want case-sensitivity, because
- // browsers tend to disagree about whether elements & attributes
- // should be upper/lower case. If you're running xpaths in an
- // XSLT instance, you probably DO want case sensitivity, as per the
- // XSL spec.
- function ExprContext(node, opt_position, opt_nodelist, opt_parent,
- opt_caseInsensitive, opt_ignoreAttributesWithoutValue,
- opt_returnOnFirstMatch)
- {
- this.node = node;
- this.position = opt_position || 0;
- this.nodelist = opt_nodelist || [ node ];
- this.variables = {};
- this.parent = opt_parent || null;
- this.caseInsensitive = opt_caseInsensitive || false;
- this.ignoreAttributesWithoutValue = opt_ignoreAttributesWithoutValue || false;
- this.returnOnFirstMatch = opt_returnOnFirstMatch || false;
- if (opt_parent) {
- this.root = opt_parent.root;
- } else if (this.node.nodeType == DOM_DOCUMENT_NODE) {
- // NOTE(mesch): DOM Spec stipulates that the ownerDocument of a
- // document is null. Our root, however is the document that we are
- // processing, so the initial context is created from its document
- // node, which case we must handle here explcitly.
- this.root = node;
- } else {
- this.root = node.ownerDocument;
- }
- }
- ExprContext.prototype.clone = function(opt_node, opt_position, opt_nodelist) {
- return new ExprContext(
- opt_node || this.node,
- typeof opt_position != 'undefined' ? opt_position : this.position,
- opt_nodelist || this.nodelist, this, this.caseInsensitive,
- this.ignoreAttributesWithoutValue, this.returnOnFirstMatch);
- };
- ExprContext.prototype.setVariable = function(name, value) {
- if (value instanceof StringValue || value instanceof BooleanValue ||
- value instanceof NumberValue || value instanceof NodeSetValue) {
- this.variables[name] = value;
- return;
- }
- if ('true' === value) {
- this.variables[name] = new BooleanValue(true);
- } else if ('false' === value) {
- this.variables[name] = new BooleanValue(false);
- } else if (TOK_NUMBER.re.test(value)) {
- this.variables[name] = new NumberValue(value);
- } else {
- // DGF What if it's null?
- this.variables[name] = new StringValue(value);
- }
- };
- ExprContext.prototype.getVariable = function(name) {
- if (typeof this.variables[name] != 'undefined') {
- return this.variables[name];
- } else if (this.parent) {
- return this.parent.getVariable(name);
- } else {
- return null;
- }
- };
- ExprContext.prototype.setNode = function(position) {
- this.node = this.nodelist[position];
- this.position = position;
- };
- ExprContext.prototype.contextSize = function() {
- return this.nodelist.length;
- };
- ExprContext.prototype.isCaseInsensitive = function() {
- return this.caseInsensitive;
- };
- ExprContext.prototype.setCaseInsensitive = function(caseInsensitive) {
- return this.caseInsensitive = caseInsensitive;
- };
- ExprContext.prototype.isIgnoreAttributesWithoutValue = function() {
- return this.ignoreAttributesWithoutValue;
- };
- ExprContext.prototype.setIgnoreAttributesWithoutValue = function(ignore) {
- return this.ignoreAttributesWithoutValue = ignore;
- };
- ExprContext.prototype.isReturnOnFirstMatch = function() {
- return this.returnOnFirstMatch;
- };
- ExprContext.prototype.setReturnOnFirstMatch = function(returnOnFirstMatch) {
- return this.returnOnFirstMatch = returnOnFirstMatch;
- };
- // XPath expression values. They are what XPath expressions evaluate
- // to. Strangely, the different value types are not specified in the
- // XPath syntax, but only in the semantics, so they don't show up as
- // nonterminals in the grammar. Yet, some expressions are required to
- // evaluate to particular types, and not every type can be coerced
- // into every other type. Although the types of XPath values are
- // similar to the types present in JavaScript, the type coercion rules
- // are a bit peculiar, so we explicitly model XPath types instead of
- // mapping them onto JavaScript types. (See XPath spec.)
- //
- // The four types are:
- //
- // StringValue
- //
- // NumberValue
- //
- // BooleanValue
- //
- // NodeSetValue
- //
- // The common interface of the value classes consists of methods that
- // implement the XPath type coercion rules:
- //
- // stringValue() -- returns the value as a JavaScript String,
- //
- // numberValue() -- returns the value as a JavaScript Number,
- //
- // booleanValue() -- returns the value as a JavaScript Boolean,
- //
- // nodeSetValue() -- returns the value as a JavaScript Array of DOM
- // Node objects.
- //
- function StringValue(value) {
- this.value = value;
- this.type = 'string';
- }
- StringValue.prototype.stringValue = function() {
- return this.value;
- }
- StringValue.prototype.booleanValue = function() {
- return this.value.length > 0;
- }
- StringValue.prototype.numberValue = function() {
- return this.value - 0;
- }
- StringValue.prototype.nodeSetValue = function() {
- throw this;
- }
- function BooleanValue(value) {
- this.value = value;
- this.type = 'boolean';
- }
- BooleanValue.prototype.stringValue = function() {
- return '' + this.value;
- }
- BooleanValue.prototype.booleanValue = function() {
- return this.value;
- }
- BooleanValue.prototype.numberValue = function() {
- return this.value ? 1 : 0;
- }
- BooleanValue.prototype.nodeSetValue = function() {
- throw this;
- }
- function NumberValue(value) {
- this.value = value;
- this.type = 'number';
- }
- NumberValue.prototype.stringValue = function() {
- return '' + this.value;
- }
- NumberValue.prototype.booleanValue = function() {
- return !!this.value;
- }
- NumberValue.prototype.numberValue = function() {
- return this.value - 0;
- }
- NumberValue.prototype.nodeSetValue = function() {
- throw this;
- }
- function NodeSetValue(value) {
- this.value = value;
- this.type = 'node-set';
- }
- NodeSetValue.prototype.stringValue = function() {
- if (this.value.length == 0) {
- return '';
- } else {
- return xmlValue(this.value[0]);
- }
- }
- NodeSetValue.prototype.booleanValue = function() {
- return this.value.length > 0;
- }
- NodeSetValue.prototype.numberValue = function() {
- return this.stringValue() - 0;
- }
- NodeSetValue.prototype.nodeSetValue = function() {
- return this.value;
- };
- // XPath expressions. They are used as nodes in the parse tree and
- // possess an evaluate() method to compute an XPath value given an XPath
- // context. Expressions are returned from the parser. Teh set of
- // expression classes closely mirrors the set of non terminal symbols
- // in the grammar. Every non trivial nonterminal symbol has a
- // corresponding expression class.
- //
- // The common expression interface consists of the following methods:
- //
- // evaluate(context) -- evaluates the expression, returns a value.
- //
- // toString() -- returns the XPath text representation of the
- // expression (defined in xsltdebug.js).
- //
- // parseTree(indent) -- returns a parse tree representation of the
- // expression (defined in xsltdebug.js).
- function TokenExpr(m) {
- this.value = m;
- }
- TokenExpr.prototype.evaluate = function() {
- return new StringValue(this.value);
- };
- function LocationExpr() {
- this.absolute = false;
- this.steps = [];
- }
- LocationExpr.prototype.appendStep = function(s) {
- var combinedStep = this._combineSteps(this.steps[this.steps.length-1], s);
- if (combinedStep) {
- this.steps[this.steps.length-1] = combinedStep;
- } else {
- this.steps.push(s);
- }
- }
- LocationExpr.prototype.prependStep = function(s) {
- var combinedStep = this._combineSteps(s, this.steps[0]);
- if (combinedStep) {
- this.steps[0] = combinedStep;
- } else {
- this.steps.unshift(s);
- }
- };
- // DGF try to combine two steps into one step (perf enhancement)
- LocationExpr.prototype._combineSteps = function(prevStep, nextStep) {
- if (!prevStep) return null;
- if (!nextStep) return null;
- var hasPredicates = (prevStep.predicates && prevStep.predicates.length > 0);
- if (prevStep.nodetest instanceof NodeTestAny && !hasPredicates) {
- // maybe suitable to be combined
- if (prevStep.axis == xpathAxis.DESCENDANT_OR_SELF) {
- if (nextStep.axis == xpathAxis.CHILD) {
- // HBC - commenting out, because this is not a valid reduction
- //nextStep.axis = xpathAxis.DESCENDANT;
- //return nextStep;
- } else if (nextStep.axis == xpathAxis.SELF) {
- nextStep.axis = xpathAxis.DESCENDANT_OR_SELF;
- return nextStep;
- }
- } else if (prevStep.axis == xpathAxis.DESCENDANT) {
- if (nextStep.axis == xpathAxis.SELF) {
- nextStep.axis = xpathAxis.DESCENDANT;
- return nextStep;
- }
- }
- }
- return null;
- }
- LocationExpr.prototype.evaluate = function(ctx) {
- var start;
- if (this.absolute) {
- start = ctx.root;
- } else {
- start = ctx.node;
- }
- var nodes = [];
- xPathStep(nodes, this.steps, 0, start, ctx);
- return new NodeSetValue(nodes);
- };
- function xPathStep(nodes, steps, step, input, ctx) {
- var s = steps[step];
- var ctx2 = ctx.clone(input);
-
- if (ctx.returnOnFirstMatch && !s.hasPositionalPredicate) {
- var nodelist = s.evaluate(ctx2).nodeSetValue();
- // the predicates were not processed in the last evaluate(), so that we can
- // process them here with the returnOnFirstMatch optimization. We do a
- // depth-first grab at any nodes that pass the predicate tests. There is no
- // way to optimize when predicates contain positional selectors, including
- // indexes or uses of the last() or position() functions, because they
- // typically require the entire nodelist for context. Process without
- // optimization if we encounter such selectors.
- var nLength = nodelist.length;
- var pLength = s.predicate.length;
- nodelistLoop:
- for (var i = 0; i < nLength; ++i) {
- var n = nodelist[i];
- for (var j = 0; j < pLength; ++j) {
- if (!s.predicate[j].evaluate(ctx.clone(n, i, nodelist)).booleanValue()) {
- continue nodelistLoop;
- }
- }
- // n survived the predicate tests!
- if (step == steps.length - 1) {
- nodes.push(n);
- }
- else {
- xPathStep(nodes, steps, step + 1, n, ctx);
- }
- if (nodes.length > 0) {
- break;
- }
- }
- }
- else {
- // set returnOnFirstMatch to false for the cloned ExprContext, because
- // behavior in StepExpr.prototype.evaluate is driven off its value. Note
- // that the original context may still have true for this value.
- ctx2.returnOnFirstMatch = false;
- var nodelist = s.evaluate(ctx2).nodeSetValue();
- for (var i = 0; i < nodelist.length; ++i) {
- if (step == steps.length - 1) {
- nodes.push(nodelist[i]);
- } else {
- xPathStep(nodes, steps, step + 1, nodelist[i], ctx);
- }
- }
- }
- }
- function StepExpr(axis, nodetest, opt_predicate) {
- this.axis = axis;
- this.nodetest = nodetest;
- this.predicate = opt_predicate || [];
- this.hasPositionalPredicate = false;
- for (var i = 0; i < this.predicate.length; ++i) {
- if (predicateExprHasPositionalSelector(this.predicate[i].expr)) {
- this.hasPositionalPredicate = true;
- break;
- }
- }
- }
- StepExpr.prototype.appendPredicate = function(p) {
- this.predicate.push(p);
- if (!this.hasPositionalPredicate) {
- this.hasPositionalPredicate = predicateExprHasPositionalSelector(p.expr);
- }
- }
- StepExpr.prototype.evaluate = function(ctx) {
- var input = ctx.node;
- var nodelist = [];
- var skipNodeTest = false;
-
- if (this.nodetest instanceof NodeTestAny) {
- skipNodeTest = true;
- }
- // NOTE(mesch): When this was a switch() statement, it didn't work
- // in Safari/2.0. Not sure why though; it resulted in the JavaScript
- // console output "undefined" (without any line number or so).
- if (this.axis == xpathAxis.ANCESTOR_OR_SELF) {
- nodelist.push(input);
- for (var n = input.parentNode; n; n = n.parentNode) {
- nodelist.push(n);
- }
- } else if (this.axis == xpathAxis.ANCESTOR) {
- for (var n = input.parentNode; n; n = n.parentNode) {
- nodelist.push(n);
- }
- } else if (this.axis == xpathAxis.ATTRIBUTE) {
- if (this.nodetest.name != undefined) {
- // single-attribute step
- if (input.attributes) {
- if (input.attributes instanceof Array) {
- // probably evaluating on document created by xmlParse()
- copyArray(nodelist, input.attributes);
- }
- else {
- if (this.nodetest.name == 'style') {
- var value = input.getAttribute('style');
- if (value && typeof(value) != 'string') {
- // this is the case where indexing into the attributes array
- // doesn't give us the attribute node in IE - we create our own
- // node instead
- nodelist.push(XNode.create(DOM_ATTRIBUTE_NODE, 'style',
- value.cssText, document));
- }
- else {
- nodelist.push(input.attributes[this.nodetest.name]);
- }
- }
- else {
- nodelist.push(input.attributes[this.nodetest.name]);
- }
- }
- }
- }
- else {
- // all-attributes step
- if (ctx.ignoreAttributesWithoutValue) {
- copyArrayIgnoringAttributesWithoutValue(nodelist, input.attributes);
- }
- else {
- copyArray(nodelist, input.attributes);
- }
- }
-
- } else if (this.axis == xpathAxis.CHILD) {
- copyArray(nodelist, input.childNodes);
- } else if (this.axis == xpathAxis.DESCENDANT_OR_SELF) {
- if (this.nodetest.evaluate(ctx).booleanValue()) {
- nodelist.push(input);
- }
- var tagName = xpathExtractTagNameFromNodeTest(this.nodetest);
- xpathCollectDescendants(nodelist, input, tagName);
- if (tagName) skipNodeTest = true;
- } else if (this.axis == xpathAxis.DESCENDANT) {
- var tagName = xpathExtractTagNameFromNodeTest(this.nodetest);
- xpathCollectDescendants(nodelist, input, tagName);
- if (tagName) skipNodeTest = true;
- } else if (this.axis == xpathAxis.FOLLOWING) {
- for (var n = input; n; n = n.parentNode) {
- for (var nn = n.nextSibling; nn; nn = nn.nextSibling) {
- nodelist.push(nn);
- xpathCollectDescendants(nodelist, nn);
- }
- }
- } else if (this.axis == xpathAxis.FOLLOWING_SIBLING) {
- for (var n = input.nextSibling; n; n = n.nextSibling) {
- nodelist.push(n);
- }
- } else if (this.axis == xpathAxis.NAMESPACE) {
- alert('not implemented: axis namespace');
- } else if (this.axis == xpathAxis.PARENT) {
- if (input.parentNode) {
- nodelist.push(input.parentNode);
- }
- } else if (this.axis == xpathAxis.PRECEDING) {
- for (var n = input; n; n = n.parentNode) {
- for (var nn = n.previousSibling; nn; nn = nn.previousSibling) {
- nodelist.push(nn);
- xpathCollectDescendantsReverse(nodelist, nn);
- }
- }
- } else if (this.axis == xpathAxis.PRECEDING_SIBLING) {
- for (var n = input.previousSibling; n; n = n.previousSibling) {
- nodelist.push(n);
- }
- } else if (this.axis == xpathAxis.SELF) {
- nodelist.push(input);
- } else {
- throw 'ERROR -- NO SUCH AXIS: ' + this.axis;
- }
- if (!skipNodeTest) {
- // process node test
- var nodelist0 = nodelist;
- nodelist = [];
- for (var i = 0; i < nodelist0.length; ++i) {
- var n = nodelist0[i];
- if (this.nodetest.evaluate(ctx.clone(n, i, nodelist0)).booleanValue()) {
- nodelist.push(n);
- }
- }
- }
- // process predicates
- if (!ctx.returnOnFirstMatch) {
- for (var i = 0; i < this.predicate.length; ++i) {
- var nodelist0 = nodelist;
- nodelist = [];
- for (var ii = 0; ii < nodelist0.length; ++ii) {
- var n = nodelist0[ii];
- if (this.predicate[i].evaluate(ctx.clone(n, ii, nodelist0)).booleanValue()) {
- nodelist.push(n);
- }
- }
- }
- }
- return new NodeSetValue(nodelist);
- };
- function NodeTestAny() {
- this.value = new BooleanValue(true);
- }
- NodeTestAny.prototype.evaluate = function(ctx) {
- return this.value;
- };
- function NodeTestElementOrAttribute() {}
- NodeTestElementOrAttribute.prototype.evaluate = function(ctx) {
- return new BooleanValue(
- ctx.node.nodeType == DOM_ELEMENT_NODE ||
- ctx.node.nodeType == DOM_ATTRIBUTE_NODE);
- }
- function NodeTestText() {}
- NodeTestText.prototype.evaluate = function(ctx) {
- return new BooleanValue(ctx.node.nodeType == DOM_TEXT_NODE);
- }
- function NodeTestComment() {}
- NodeTestComment.prototype.evaluate = function(ctx) {
- return new BooleanValue(ctx.node.nodeType == DOM_COMMENT_NODE);
- }
- function NodeTestPI(target) {
- this.target = target;
- }
- NodeTestPI.prototype.evaluate = function(ctx) {
- return new
- BooleanValue(ctx.node.nodeType == DOM_PROCESSING_INSTRUCTION_NODE &&
- (!this.target || ctx.node.nodeName == this.target));
- }
- function NodeTestNC(nsprefix) {
- this.regex = new RegExp("^" + nsprefix + ":");
- this.nsprefix = nsprefix;
- }
- NodeTestNC.prototype.evaluate = function(ctx) {
- var n = ctx.node;
- return new BooleanValue(this.regex.match(n.nodeName));
- }
- function NodeTestName(name) {
- this.name = name;
- this.re = new RegExp('^' + name + '$', "i");
- }
- NodeTestName.prototype.evaluate = function(ctx) {
- var n = ctx.node;
- if (ctx.caseInsensitive) {
- if (n.nodeName.length != this.name.length) return new BooleanValue(false);
- return new BooleanValue(this.re.test(n.nodeName));
- } else {
- return new BooleanValue(n.nodeName == this.name);
- }
- }
- function PredicateExpr(expr) {
- this.expr = expr;
- }
- PredicateExpr.prototype.evaluate = function(ctx) {
- var v = this.expr.evaluate(ctx);
- if (v.type == 'number') {
- // NOTE(mesch): Internally, position is represented starting with
- // 0, however in XPath position starts with 1. See functions
- // position() and last().
- return new BooleanValue(ctx.position == v.numberValue() - 1);
- } else {
- return new BooleanValue(v.booleanValue());
- }
- };
- function FunctionCallExpr(name) {
- this.name = name;
- this.args = [];
- }
- FunctionCallExpr.prototype.appendArg = function(arg) {
- this.args.push(arg);
- };
- FunctionCallExpr.prototype.evaluate = function(ctx) {
- var fn = '' + this.name.value;
- var f = this.xpathfunctions[fn];
- if (f) {
- return f.call(this, ctx);
- } else {
- xpathLog('XPath NO SUCH FUNCTION ' + fn);
- return new BooleanValue(false);
- }
- };
- FunctionCallExpr.prototype.xpathfunctions = {
- 'last': function(ctx) {
- assert(this.args.length == 0);
- // NOTE(mesch): XPath position starts at 1.
- return new NumberValue(ctx.contextSize());
- },
- 'position': function(ctx) {
- assert(this.args.length == 0);
- // NOTE(mesch): XPath position starts at 1.
- return new NumberValue(ctx.position + 1);
- },
- 'count': function(ctx) {
- assert(this.args.length == 1);
- var v = this.args[0].evaluate(ctx);
- return new NumberValue(v.nodeSetValue().length);
- },
- 'id': function(ctx) {
- assert(this.args.length == 1);
- var e = this.args[0].evaluate(ctx);
- var ret = [];
- var ids;
- if (e.type == 'node-set') {
- ids = [];
- var en = e.nodeSetValue();
- for (var i = 0; i < en.length; ++i) {
- var v = xmlValue(en[i]).split(/\s+/);
- for (var ii = 0; ii < v.length; ++ii) {
- ids.push(v[ii]);
- }
- }
- } else {
- ids = e.stringValue().split(/\s+/);
- }
- var d = ctx.root;
- for (var i = 0; i < ids.length; ++i) {
- var n = d.getElementById(ids[i]);
- if (n) {
- ret.push(n);
- }
- }
- return new NodeSetValue(ret);
- },
- 'local-name': function(ctx) {
- alert('not implmented yet: XPath function local-name()');
- },
- 'namespace-uri': function(ctx) {
- alert('not implmented yet: XPath function namespace-uri()');
- },
- 'name': function(ctx) {
- assert(this.args.length == 1 || this.args.length == 0);
- var n;
- if (this.args.length == 0) {
- n = [ ctx.node ];
- } else {
- n = this.args[0].evaluate(ctx).nodeSetValue();
- }
- if (n.length == 0) {
- return new StringValue('');
- } else {
- return new StringValue(n[0].nodeName);
- }
- },
- 'string': function(ctx) {
- assert(this.args.length == 1 || this.args.length == 0);
- if (this.args.length == 0) {
- return new StringValue(new NodeSetValue([ ctx.node ]).stringValue());
- } else {
- return new StringValue(this.args[0].evaluate(ctx).stringValue());
- }
- },
- 'concat': function(ctx) {
- var ret = '';
- for (var i = 0; i < this.args.length; ++i) {
- ret += this.args[i].evaluate(ctx).stringValue();
- }
- return new StringValue(ret);
- },
- 'starts-with': function(ctx) {
- assert(this.args.length == 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- return new BooleanValue(s0.indexOf(s1) == 0);
- },
-
- 'ends-with': function(ctx) {
- assert(this.args.length == 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- var re = new RegExp(RegExp.escape(s1) + '$');
- return new BooleanValue(re.test(s0));
- },
- 'contains': function(ctx) {
- assert(this.args.length == 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- return new BooleanValue(s0.indexOf(s1) != -1);
- },
- 'substring-before': function(ctx) {
- assert(this.args.length == 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- var i = s0.indexOf(s1);
- var ret;
- if (i == -1) {
- ret = '';
- } else {
- ret = s0.substr(0,i);
- }
- return new StringValue(ret);
- },
- 'substring-after': function(ctx) {
- assert(this.args.length == 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- var i = s0.indexOf(s1);
- var ret;
- if (i == -1) {
- ret = '';
- } else {
- ret = s0.substr(i + s1.length);
- }
- return new StringValue(ret);
- },
- 'substring': function(ctx) {
- // NOTE: XPath defines the position of the first character in a
- // string to be 1, in JavaScript this is 0 ([XPATH] Section 4.2).
- assert(this.args.length == 2 || this.args.length == 3);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).numberValue();
- var ret;
- if (this.args.length == 2) {
- var i1 = Math.max(0, Math.round(s1) - 1);
- ret = s0.substr(i1);
- } else {
- var s2 = this.args[2].evaluate(ctx).numberValue();
- var i0 = Math.round(s1) - 1;
- var i1 = Math.max(0, i0);
- var i2 = Math.round(s2) - Math.max(0, -i0);
- ret = s0.substr(i1, i2);
- }
- return new StringValue(ret);
- },
- 'string-length': function(ctx) {
- var s;
- if (this.args.length > 0) {
- s = this.args[0].evaluate(ctx).stringValue();
- } else {
- s = new NodeSetValue([ ctx.node ]).stringValue();
- }
- return new NumberValue(s.length);
- },
- 'normalize-space': function(ctx) {
- var s;
- if (this.args.length > 0) {
- s = this.args[0].evaluate(ctx).stringValue();
- } else {
- s = new NodeSetValue([ ctx.node ]).stringValue();
- }
- s = s.replace(/^\s*/,'').replace(/\s*$/,'').replace(/\s+/g, ' ');
- return new StringValue(s);
- },
- 'translate': function(ctx) {
- assert(this.args.length == 3);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- var s2 = this.args[2].evaluate(ctx).stringValue();
- for (var i = 0; i < s1.length; ++i) {
- s0 = s0.replace(new RegExp(s1.charAt(i), 'g'), s2.charAt(i));
- }
- return new StringValue(s0);
- },
-
- 'matches': function(ctx) {
- assert(this.args.length >= 2);
- var s0 = this.args[0].evaluate(ctx).stringValue();
- var s1 = this.args[1].evaluate(ctx).stringValue();
- if (this.args.length > 2) {
- var s2 = this.args[2].evaluate(ctx).stringValue();
- if (/[^mi]/.test(s2)) {
- throw 'Invalid regular expression syntax: ' + s2;
- }
- }
-
- try {
- var re = new RegExp(s1, s2);
- }
- catch (e) {
- throw 'Invalid matches argument: ' + s1;
- }
- return new BooleanValue(re.test(s0));
- },
- 'boolean': function(ctx) {
- assert(this.args.length == 1);
- return new BooleanValue(this.args[0].evaluate(ctx).booleanValue());
- },
- 'not': function(ctx) {
- assert(this.args.length == 1);
- var ret = !this.args[0].evaluate(ctx).booleanValue();
- return new BooleanValue(ret);
- },
- 'true': function(ctx) {
- assert(this.args.length == 0);
- return new BooleanValue(true);
- },
- 'false': function(ctx) {
- assert(this.args.length == 0);
- return new BooleanValue(false);
- },
- 'lang': function(ctx) {
- assert(this.args.length == 1);
- var lang = this.args[0].evaluate(ctx).stringValue();
- var xmllang;
- var n = ctx.node;
- while (n && n != n.parentNode /* just in case ... */) {
- xmllang = n.getAttribute('xml:lang');
- if (xmllang) {
- break;
- }
- n = n.parentNode;
- }
- if (!xmllang) {
- return new BooleanValue(false);
- } else {
- var re = new RegExp('^' + lang + '$', 'i');
- return new BooleanValue(xmllang.match(re) ||
- xmllang.replace(/_.*$/,'').match(re));
- }
- },
- 'number': function(ctx) {
- assert(this.args.length == 1 || this.args.length == 0);
- if (this.args.length == 1) {
- return new NumberValue(this.args[0].evaluate(ctx).numberValue());
- } else {
- return new NumberValue(new NodeSetValue([ ctx.node ]).numberValue());
- }
- },
- 'sum': function(ctx) {
- assert(this.args.length == 1);
- var n = this.args[0].evaluate(ctx).nodeSetValue();
- var sum = 0;
- for (var i = 0; i < n.length; ++i) {
- sum += xmlValue(n[i]) - 0;
- }
- return new NumberValue(sum);
- },
- 'floor': function(ctx) {
- assert(this.args.length == 1);
- var num = this.args[0].evaluate(ctx).numberValue();
- return new NumberValue(Math.floor(num));
- },
- 'ceiling': function(ctx) {
- assert(this.args.length == 1);
- var num = this.args[0].evaluate(ctx).numberValue();
- return new NumberValue(Math.ceil(num));
- },
- 'round': function(ctx) {
- assert(this.args.length == 1);
- var num = this.args[0].evaluate(ctx).numberValue();
- return new NumberValue(Math.round(num));
- },
- // TODO(mesch): The following functions are custom. There is a
- // standard that defines how to add functions, which should be
- // applied here.
- 'ext-join': function(ctx) {
- assert(this.args.length == 2);
- var nodes = this.args[0].evaluate(ctx).nodeSetValue();
- var delim = this.args[1].evaluate(ctx).stringValue();
- var ret = '';
- for (var i = 0; i < nodes.length; ++i) {
- if (ret) {
- ret += delim;
- }
- ret += xmlValue(nodes[i]);
- }
- return new StringValue(ret);
- },
- // ext-if() evaluates and returns its second argument, if the
- // boolean value of its first argument is true, otherwise it
- // evaluates and returns its third argument.
- 'ext-if': function(ctx) {
- assert(this.args.length == 3);
- if (this.args[0].evaluate(ctx).booleanValue()) {
- return this.args[1].evaluate(ctx);
- } else {
- return this.args[2].evaluate(ctx);
- }
- },
- // ext-cardinal() evaluates its single argument as a number, and
- // returns the current node that many times. It can be used in the
- // select attribute to iterate over an integer range.
- 'ext-cardinal': function(ctx) {
- assert(this.args.length >= 1);
- var c = this.args[0].evaluate(ctx).numberValue();
- var ret = [];
- for (var i = 0; i < c; ++i) {
- ret.push(ctx.node);
- }
- return new NodeSetValue(ret);
- }
- };
- function UnionExpr(expr1, expr2) {
- this.expr1 = expr1;
- this.expr2 = expr2;
- }
- UnionExpr.prototype.evaluate = function(ctx) {
- var nodes1 = this.expr1.evaluate(ctx).nodeSetValue();
- var nodes2 = this.expr2.evaluate(ctx).nodeSetValue();
- var I1 = nodes1.length;
- for (var i2 = 0; i2 < nodes2.length; ++i2) {
- var n = nodes2[i2];
- var inBoth = false;
- for (var i1 = 0; i1 < I1; ++i1) {
- if (nodes1[i1] == n) {
- inBoth = true;
- i1 = I1; // break inner loop
- }
- }
- if (!inBoth) {
- nodes1.push(n);
- }
- }
- return new NodeSetValue(nodes1);
- };
- function PathExpr(filter, rel) {
- this.filter = filter;
- this.rel = rel;
- }
- PathExpr.prototype.evaluate = function(ctx) {
- // the filter expression should be evaluated in its entirety with no
- // optimization, as we can't backtrack to it after having moved on to
- // evaluating the relative location path
- var flag = ctx.returnOnFirstMatch;
- ctx.setReturnOnFirstMatch(false);
- var nodes = this.filter.evaluate(ctx).nodeSetValue();
- ctx.setReturnOnFirstMatch(flag);
-
- var nodes1 = [];
- if (ctx.returnOnFirstMatch) {
- for (var i = 0; i < nodes.length; ++i) {
- nodes1 = this.rel.evaluate(ctx.clone(nodes[i], i, nodes)).nodeSetValue();
- if (nodes1.length > 0) {
- break;
- }
- }
- return new NodeSetValue(nodes1);
- }
- else {
- for (var i = 0; i < nodes.length; ++i) {
- var nodes0 = this.rel.evaluate(ctx.clone(nodes[i], i, nodes)).nodeSetValue();
- for (var ii = 0; ii < nodes0.length; ++ii) {
- nodes1.push(nodes0[ii]);
- }
- }
- return new NodeSetValue(nodes1);
- }
- };
- function FilterExpr(expr, predicate) {
- this.expr = expr;
- this.predicate = predicate;
- }
- FilterExpr.prototype.evaluate = function(ctx) {
- var nodes = this.expr.evaluate(ctx).nodeSetValue();
- for (var i = 0; i < this.predicate.length; ++i) {
- var nodes0 = nodes;
- nodes = [];
- for (var j = 0; j < nodes0.length; ++j) {
- var n = nodes0[j];
- if (this.predicate[i].evaluate(ctx.clone(n, j, nodes0)).booleanValue()) {
- nodes.push(n);
- }
- }
- }
- return new NodeSetValue(nodes);
- }
- function UnaryMinusExpr(expr) {
- this.expr = expr;
- }
- UnaryMinusExpr.prototype.evaluate = function(ctx) {
- return new NumberValue(-this.expr.evaluate(ctx).numberValue());
- };
- function BinaryExpr(expr1, op, expr2) {
- this.expr1 = expr1;
- this.expr2 = expr2;
- this.op = op;
- }
- BinaryExpr.prototype.evaluate = function(ctx) {
- var ret;
- switch (this.op.value) {
- case 'or':
- ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() ||
- this.expr2.evaluate(ctx).booleanValue());
- break;
- case 'and':
- ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() &&
- this.expr2.evaluate(ctx).booleanValue());
- break;
- case '+':
- ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() +
- this.expr2.evaluate(ctx).numberValue());
- break;
- case '-':
- ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() -
- this.expr2.evaluate(ctx).numberValue());
- break;
- case '*':
- ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() *
- this.expr2.evaluate(ctx).numberValue());
- break;
- case 'mod':
- ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() %
- this.expr2.evaluate(ctx).numberValue());
- break;
- case 'div':
- ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() /
- this.expr2.evaluate(ctx).numberValue());
- break;
- case '=':
- ret = this.compare(ctx, function(x1, x2) { return x1 == x2; });
- break;
- case '!=':
- ret = this.compare(ctx, function(x1, x2) { return x1 != x2; });
- break;
- case '<':
- ret = this.compare(ctx, function(x1, x2) { return x1 < x2; });
- break;
- case '<=':
- ret = this.compare(ctx, function(x1, x2) { return x1 <= x2; });
- break;
- case '>':
- ret = this.compare(ctx, function(x1, x2) { return x1 > x2; });
- break;
- case '>=':
- ret = this.compare(ctx, function(x1, x2) { return x1 >= x2; });
- break;
- default:
- alert('BinaryExpr.evaluate: ' + this.op.value);
- }
- return ret;
- };
- BinaryExpr.prototype.compare = function(ctx, cmp) {
- var v1 = this.expr1.evaluate(ctx);
- var v2 = this.expr2.evaluate(ctx);
- var ret;
- if (v1.type == 'node-set' && v2.type == 'node-set') {
- var n1 = v1.nodeSetValue();
- var n2 = v2.nodeSetValue();
- ret = false;
- for (var i1 = 0; i1 < n1.length; ++i1) {
- for (var i2 = 0; i2 < n2.length; ++i2) {
- if (cmp(xmlValue(n1[i1]), xmlValue(n2[i2]))) {
- ret = true;
- // Break outer loop. Labels confuse the jscompiler and we
- // don't use them.
- i2 = n2.length;
- i1 = n1.length;
- }
- }
- }
- } else if (v1.type == 'node-set' || v2.type == 'node-set') {
- if (v1.type == 'number') {
- var s = v1.numberValue();
- var n = v2.nodeSetValue();
- ret = false;
- for (var i = 0; i < n.length; ++i) {
- var nn = xmlValue(n[i]) - 0;
- if (cmp(s, nn)) {
- ret = true;
- break;
- }
- }
- } else if (v2.type == 'number') {
- var n = v1.nodeSetValue();
- var s = v2.numberValue();
- ret = false;
- for (var i = 0; i < n.length; ++i) {
- var nn = xmlValue(n[i]) - 0;
- if (cmp(nn, s)) {
- ret = true;
- break;
- }
- }
- } else if (v1.type == 'string') {
- var s = v1.stringValue();
- var n = v2.nodeSetValue();
- ret = false;
- for (var i = 0; i < n.length; ++i) {
- var nn = xmlValue(n[i]);
- if (cmp(s, nn)) {
- ret = true;
- break;
- }
- }
- } else if (v2.type == 'string') {
- var n = v1.nodeSetValue();
- var s = v2.stringValue();
- ret = false;
- for (var i = 0; i < n.length; ++i) {
- var nn = xmlValue(n[i]);
- if (cmp(nn, s)) {
- ret = true;
- break;
- }
- }
- } else {
- ret = cmp(v1.booleanValue(), v2.booleanValue());
- }
- } else if (v1.type == 'boolean' || v2.type == 'boolean') {
- ret = cmp(v1.booleanValue(), v2.booleanValue());
- } else if (v1.type == 'number' || v2.type == 'number') {
- ret = cmp(v1.numberValue(), v2.numberValue());
- } else {
- ret = cmp(v1.stringValue(), v2.stringValue());
- }
- return new BooleanValue(ret);
- }
- function LiteralExpr(value) {
- this.value = value;
- }
- LiteralExpr.prototype.evaluate = function(ctx) {
- return new StringValue(this.value);
- };
- function NumberExpr(value) {
- this.value = value;
- }
- NumberExpr.prototype.evaluate = function(ctx) {
- return new NumberValue(this.value);
- };
- function VariableExpr(name) {
- this.name = name;
- }
- VariableExpr.prototype.evaluate = function(ctx) {
- return ctx.getVariable(this.name);
- }
- // Factory functions for semantic values (i.e. Expressions) of the
- // productions in the grammar. When a production is matched to reduce
- // the current parse state stack, the function is called with the
- // semantic values of the matched elements as arguments, and returns
- // another semantic value. The semantic value is a node of the parse
- // tree, an expression object with an evaluate() method that evaluates the
- // expression in an actual context. These factory functions are used
- // in the specification of the grammar rules, below.
- function makeTokenExpr(m) {
- return new TokenExpr(m);
- }
- function passExpr(e) {
- return e;
- }
- function makeLocationExpr1(slash, rel) {
- rel.absolute = true;
- return rel;
- }
- function makeLocationExpr2(dslash, rel) {
- rel.absolute = true;
- rel.prependStep(makeAbbrevStep(dslash.value));
- return rel;
- }
- function makeLocationExpr3(slash) {
- var ret = new LocationExpr();
- ret.appendStep(makeAbbrevStep('.'));
- ret.absolute = true;
- return ret;
- }
- function makeLocationExpr4(dslash) {
- var ret = new LocationExpr();
- ret.absolute = true;
- ret.appendStep(makeAbbrevStep(dslash.value));
- return ret;
- }
- function makeLocationExpr5(step) {
- var ret = new LocationExpr();
- ret.appendStep(step);
- return ret;
- }
- function makeLocationExpr6(rel, slash, step) {
- rel.appendStep(step);
- return rel;
- }
- function makeLocationExpr7(rel, dslash, step) {
- rel.appendStep(makeAbbrevStep(dslash.value));
- rel.appendStep(step);
- return rel;
- }
- function makeStepExpr1(dot) {
- return makeAbbrevStep(dot.value);
- }
- function makeStepExpr2(ddot) {
- return makeAbbrevStep(ddot.value);
- }
- function makeStepExpr3(axisname, axis, nodetest) {
- return new StepExpr(axisname.value, nodetest);
- }
- function makeStepExpr4(at, nodetest) {
- return new StepExpr('attribute', nodetest);
- }
- function makeStepExpr5(nodetest) {
- return new StepExpr('child', nodetest);
- }
- function makeStepExpr6(step, predicate) {
- step.appendPredicate(predicate);
- return step;
- }
- function makeAbbrevStep(abbrev) {
- switch (abbrev) {
- case '//':
- return new StepExpr('descendant-or-self', new NodeTestAny);
- case '.':
- return new StepExpr('self', new NodeTestAny);
- case '..':
- return new StepExpr('parent', new NodeTestAny);
- }
- }
- function makeNodeTestExpr1(asterisk) {
- return new NodeTestElementOrAttribute;
- }
- function makeNodeTestExpr2(ncname, colon, asterisk) {
- return new NodeTestNC(ncname.value);
- }
- function makeNodeTestExpr3(qname) {
- return new NodeTestName(qname.value);
- }
- function makeNodeTestExpr4(typeo, parenc) {
- var type = typeo.value.replace(/\s*\($/, '');
- switch(type) {
- case 'node':
- return new NodeTestAny;
- case 'text':
- return new NodeTestText;
- case 'comment':
- return new NodeTestComment;
- case 'processing-instruction':
- return new NodeTestPI('');
- }
- }
- function makeNodeTestExpr5(typeo, target, parenc) {
- var type = typeo.replace(/\s*\($/, '');
- if (type != 'processing-instruction') {
- throw type;
- }
- return new NodeTestPI(target.value);
- }
- function makePredicateExpr(pareno, expr, parenc) {
- return new PredicateExpr(expr);
- }
- function makePrimaryExpr(pareno, expr, parenc) {
- return expr;
- }
- function makeFunctionCallExpr1(name, pareno, parenc) {
- return new FunctionCallExpr(name);
- }
- function makeFunctionCallExpr2(name, pareno, arg1, args, parenc) {
- var ret = new FunctionCallExpr(name);
- ret.appendArg(arg1);
- for (var i = 0; i < args.length; ++i) {
- ret.appendArg(args[i]);
- }
- return ret;
- }
- function makeArgumentExpr(comma, expr) {
- return expr;
- }
- function makeUnionExpr(expr1, pipe, expr2) {
- return new UnionExpr(expr1, expr2);
- }
- function makePathExpr1(filter, slash, rel) {
- return new PathExpr(filter, rel);
- }
- function makePathExpr2(filter, dslash, rel) {
- rel.prependStep(makeAbbrevStep(dslash.value));
- return new PathExpr(filter, rel);
- }
- function makeFilterExpr(expr, predicates) {
- if (predicates.length > 0) {
- return new FilterExpr(expr, predicates);
- } else {
- return expr;
- }
- }
- function makeUnaryMinusExpr(minus, expr) {
- return new UnaryMinusExpr(expr);
- }
- function makeBinaryExpr(expr1, op, expr2) {
- return new BinaryExpr(expr1, op, expr2);
- }
- function makeLiteralExpr(token) {
- // remove quotes from the parsed value:
- var value = token.value.substring(1, token.value.length - 1);
- return new LiteralExpr(value);
- }
- function makeNumberExpr(token) {
- return new NumberExpr(token.value);
- }
- function makeVariableReference(dollar, name) {
- return new VariableExpr(name.value);
- }
- // Used before parsing for optimization of common simple cases. See
- // the begin of xpathParse() for which they are.
- function makeSimpleExpr(expr) {
- if (expr.charAt(0) == '$') {
- return new VariableExpr(expr.substr(1));
- } else if (expr.charAt(0) == '@') {
- var a = new NodeTestName(expr.substr(1));
- var b = new StepExpr('attribute', a);
- var c = new LocationExpr();
- c.appendStep(b);
- return c;
- } else if (expr.match(/^[0-9]+$/)) {
- return new NumberExpr(expr);
- } else {
- var a = new NodeTestName(expr);
- var b = new StepExpr('child', a);
- var c = new LocationExpr();
- c.appendStep(b);
- return c;
- }
- }
- function makeSimpleExpr2(expr) {
- var steps = stringSplit(expr, '/');
- var c = new LocationExpr();
- for (var i = 0; i < steps.length; ++i) {
- var a = new NodeTestName(steps[i]);
- var b = new StepExpr('child', a);
- c.appendStep(b);
- }
- return c;
- }
- // The axes of XPath expressions.
- var xpathAxis = {
- ANCESTOR_OR_SELF: 'ancestor-or-self',
- ANCESTOR: 'ancestor',
- ATTRIBUTE: 'attribute',
- CHILD: 'child',
- DESCENDANT_OR_SELF: 'descendant-or-self',
- DESCENDANT: 'descendant',
- FOLLOWING_SIBLING: 'following-sibling',
- FOLLOWING: 'following',
- NAMESPACE: 'namespace',
- PARENT: 'parent',
- PRECEDING_SIBLING: 'preceding-sibling',
- PRECEDING: 'preceding',
- SELF: 'self'
- };
- var xpathAxesRe = [
- xpathAxis.ANCESTOR_OR_SELF,
- xpathAxis.ANCESTOR,
- xpathAxis.ATTRIBUTE,
- xpathAxis.CHILD,
- xpathAxis.DESCENDANT_OR_SELF,
- xpathAxis.DESCENDANT,
- xpathAxis.FOLLOWING_SIBLING,
- xpathAxis.FOLLOWING,
- xpathAxis.NAMESPACE,
- xpathAxis.PARENT,
- xpathAxis.PRECEDING_SIBLING,
- xpathAxis.PRECEDING,
- xpathAxis.SELF
- ].join('|');
- // The tokens of the language. The label property is just used for
- // generating debug output. The prec property is the precedence used
- // for shift/reduce resolution. Default precedence is 0 as a lookahead
- // token and 2 on the stack. TODO(mesch): this is certainly not
- // necessary and too complicated. Simplify this!
- // NOTE: tabular formatting is the big exception, but here it should
- // be OK.
- var TOK_PIPE = { label: "|", prec: 17, re: new RegExp("^\\|") };
- var TOK_DSLASH = { label: "//", prec: 19, re: new RegExp("^//") };
- var TOK_SLASH = { label: "/", prec: 30, re: new RegExp("^/") };
- var TOK_AXIS = { label: "::", prec: 20, re: new RegExp("^::") };
- var TOK_COLON = { label: ":", prec: 1000, re: new RegExp("^:") };
- var TOK_AXISNAME = { label: "[axis]", re: new RegExp('^(' + xpathAxesRe + ')') };
- var TOK_PARENO = { label: "(", prec: 34, re: new RegExp("^\\(") };
- var TOK_PARENC = { label: ")", re: new RegExp("^\\)") };
- var TOK_DDOT = { label: "..", prec: 34, re: new RegExp("^\\.\\.") };
- var TOK_DOT = { label: ".", prec: 34, re: new RegExp("^\\.") };
- var TOK_AT = { label: "@", prec: 34, re: new RegExp("^@") };
- var TOK_COMMA = { label: ",", re: new RegExp("^,") };
- var TOK_OR = { label: "or", prec: 10, re: new RegExp("^or\\b") };
- var TOK_AND = { label: "and", prec: 11, re: new RegExp("^and\\b") };
- var TOK_EQ = { label: "=", prec: 12, re: new RegExp("^=") };
- var TOK_NEQ = { label: "!=", prec: 12, re: new RegExp("^!=") };
- var TOK_GE = { label: ">=", prec: 13, re: new RegExp("^>=") };
- var TOK_GT = { label: ">", prec: 13, re: new RegExp("^>") };
- var TOK_LE = { label: "<=", prec: 13, re: new RegExp("^<=") };
- var TOK_LT = { label: "<", prec: 13, re: new RegExp("^<") };
- var TOK_PLUS = { label: "+", prec: 14, re: new RegExp("^\\+"), left: true };
- var TOK_MINUS = { label: "-", prec: 14, re: new RegExp("^\\-"), left: true };
- var TOK_DIV = { label: "div", prec: 15, re: new RegExp("^div\\b"), left: true };
- var TOK_MOD = { label: "mod", prec: 15, re: new RegExp("^mod\\b"), left: true };
- var TOK_BRACKO = { label: "[", prec: 32, re: new RegExp("^\\[") };
- var TOK_BRACKC = { label: "]", re: new RegExp("^\\]") };
- var TOK_DOLLAR = { label: "$", re: new RegExp("^\\$") };
- var TOK_NCNAME = { label: "[ncname]", re: new RegExp('^' + XML_NC_NAME) };
- var TOK_ASTERISK = { label: "*", prec: 15, re: new RegExp("^\\*"), left: true };
- var TOK_LITERALQ = { label: "[litq]", prec: 20, re: new RegExp("^'[^\\']*'") };
- var TOK_LITERALQQ = {
- label: "[litqq]",
- prec: 20,
- re: new RegExp('^"[^\\"]*"')
- };
- var TOK_NUMBER = {
- label: "[number]",
- prec: 35,
- re: new RegExp('^\\d+(\\.\\d*)?') };
- var TOK_QNAME = {
- label: "[qname]",
- re: new RegExp('^(' + XML_NC_NAME + ':)?' + XML_NC_NAME)
- };
- var TOK_NODEO = {
- label: "[nodetest-start]",
- re: new RegExp('^(processing-instruction|comment|text|node)\\(')
- };
- // The table of the tokens of our grammar, used by the lexer: first
- // column the tag, second column a regexp to recognize it in the
- // input, third column the precedence of the token, fourth column a
- // factory function for the semantic value of the token.
- //
- // NOTE: order of this list is important, because the first match
- // counts. Cf. DDOT and DOT, and AXIS and COLON.
- var xpathTokenRules = [
- TOK_DSLASH,
- TOK_SLASH,
- TOK_DDOT,
- TOK_DOT,
- TOK_AXIS,
- TOK_COLON,
- TOK_AXISNAME,
- TOK_NODEO,
- TOK_PARENO,
- TOK_PARENC,
- TOK_BRACKO,
- TOK_BRACKC,
- TOK_AT,
- TOK_COMMA,
- TOK_OR,
- TOK_AND,
- TOK_NEQ,
- TOK_EQ,
- TOK_GE,
- TOK_GT,
- TOK_LE,
- TOK_LT,
- TOK_PLUS,
- TOK_MINUS,
- TOK_ASTERISK,
- TOK_PIPE,
- TOK_MOD,
- TOK_DIV,
- TOK_LITERALQ,
- TOK_LITERALQQ,
- TOK_NUMBER,
- TOK_QNAME,
- TOK_NCNAME,
- TOK_DOLLAR
- ];
- // All the nonterminals of the grammar. The nonterminal objects are
- // identified by object identity; the labels are used in the debug
- // output only.
- var XPathLocationPath = { label: "LocationPath" };
- var XPathRelativeLocationPath = { label: "RelativeLocationPath" };
- var XPathAbsoluteLocationPath = { label: "AbsoluteLocationPath" };
- var XPathStep = { label: "Step" };
- var XPathNodeTest = { label: "NodeTest" };
- var XPathPredicate = { label: "Predicate" };
- var XPathLiteral = { label: "Literal" };
- var XPathExpr = { label: "Expr" };
- var XPathPrimaryExpr = { label: "PrimaryExpr" };
- var XPathVariableReference = { label: "Variablereference" };
- var XPathNumber = { label: "Number" };
- var XPathFunctionCall = { label: "FunctionCall" };
- var XPathArgumentRemainder = { label: "ArgumentRemainder" };
- var XPathPathExpr = { label: "PathExpr" };
- var XPathUnionExpr = { label: "UnionExpr" };
- var XPathFilterExpr = { label: "FilterExpr" };
- var XPathDigits = { label: "Digits" };
- var xpathNonTerminals = [
- XPathLocationPath,
- XPathRelativeLocationPath,
- XPathAbsoluteLocationPath,
- XPathStep,
- XPathNodeTest,
- XPathPredicate,
- XPathLiteral,
- XPathExpr,
- XPathPrimaryExpr,
- XPathVariableReference,
- XPathNumber,
- XPathFunctionCall,
- XPathArgumentRemainder,
- XPathPathExpr,
- XPathUnionExpr,
- XPathFilterExpr,
- XPathDigits
- ];
- // Quantifiers that are used in the productions of the grammar.
- var Q_01 = { label: "?" };
- var Q_MM = { label: "*" };
- var Q_1M = { label: "+" };
- // Tag for left associativity (right assoc is implied by undefined).
- var ASSOC_LEFT = true;
- // The productions of the grammar. Columns of the table:
- //
- // - target nonterminal,
- // - pattern,
- // - precedence,
- // - semantic value factory
- //
- // The semantic value factory is a function that receives parse tree
- // nodes from the stack frames of the matched symbols as arguments and
- // returns an a node of the parse tree. The node is stored in the top
- // stack frame along with the target object of the rule. The node in
- // the parse tree is an expression object that has an evaluate() method
- // and thus evaluates XPath expressions.
- //
- // The precedence is used to decide between reducing and shifting by
- // comparing the precendence of the rule that is candidate for
- // reducing with the precedence of the look ahead token. Precedence of
- // -1 means that the precedence of the tokens in the pattern is used
- // instead. TODO: It shouldn't be necessary to explicitly assign
- // precedences to rules.
- // DGF As it stands, these precedences are purely empirical; we're
- // not sure they can be made to be consistent at all.
- var xpathGrammarRules =
- [
- [ XPathLocationPath, [ XPathRelativeLocationPath ], 18,
- passExpr ],
- [ XPathLocationPath, [ XPathAbsoluteLocationPath ], 18,
- passExpr ],
- [ XPathAbsoluteLocationPath, [ TOK_SLASH, XPathRelativeLocationPath ], 18,
- makeLocationExpr1 ],
- [ XPathAbsoluteLocationPath, [ TOK_DSLASH, XPathRelativeLocationPath ], 18,
- makeLocationExpr2 ],
- [ XPathAbsoluteLocationPath, [ TOK_SLASH ], 0,
- makeLocationExpr3 ],
- [ XPathAbsoluteLocationPath, [ TOK_DSLASH ], 0,
- makeLocationExpr4 ],
- [ XPathRelativeLocationPath, [ XPathStep ], 31,
- makeLocationExpr5 ],
- [ XPathRelativeLocationPath,
- [ XPathRelativeLocationPath, TOK_SLASH, XPathStep ], 31,
- makeLocationExpr6 ],
- [ XPathRelativeLocationPath,
- [ XPathRelativeLocationPath, TOK_DSLASH, XPathStep ], 31,
- makeLocationExpr7 ],
- [ XPathStep, [ TOK_DOT ], 33,
- makeStepExpr1 ],
- [ XPathStep, [ TOK_DDOT ], 33,
- makeStepExpr2 ],
- [ XPathStep,
- [ TOK_AXISNAME, TOK_AXIS, XPathNodeTest ], 33,
- makeStepExpr3 ],
- [ XPathStep, [ TOK_AT, XPathNodeTest ], 33,
- makeStepExpr4 ],
- [ XPathStep, [ XPathNodeTest ], 33,
- makeStepExpr5 ],
- [ XPathStep, [ XPathStep, XPathPredicate ], 33,
- makeStepExpr6 ],
- [ XPathNodeTest, [ TOK_ASTERISK ], 33,
- makeNodeTestExpr1 ],
- [ XPathNodeTest, [ TOK_NCNAME, TOK_COLON, TOK_ASTERISK ], 33,
- makeNodeTestExpr2 ],
- [ XPathNodeTest, [ TOK_QNAME ], 33,
- makeNodeTestExpr3 ],
- [ XPathNodeTest, [ TOK_NODEO, TOK_PARENC ], 33,
- makeNodeTestExpr4 ],
- [ XPathNodeTest, [ TOK_NODEO, XPathLiteral, TOK_PARENC ], 33,
- makeNodeTestExpr5 ],
- [ XPathPredicate, [ TOK_BRACKO, XPathExpr, TOK_BRACKC ], 33,
- makePredicateExpr ],
- [ XPathPrimaryExpr, [ XPathVariableReference ], 33,
- passExpr ],
- [ XPathPrimaryExpr, [ TOK_PARENO, XPathExpr, TOK_PARENC ], 33,
- makePrimaryExpr ],
- [ XPathPrimaryExpr, [ XPathLiteral ], 30,
- passExpr ],
- [ XPathPrimaryExpr, [ XPathNumber ], 30,
- passExpr ],
- [ XPathPrimaryExpr, [ XPathFunctionCall ], 31,
- passExpr ],
- [ XPathFunctionCall, [ TOK_QNAME, TOK_PARENO, TOK_PARENC ], -1,
- makeFunctionCallExpr1 ],
- [ XPathFunctionCall,
- [ TOK_QNAME, TOK_PARENO, XPathExpr, XPathArgumentRemainder, Q_MM,
- TOK_PARENC ], -1,
- makeFunctionCallExpr2 ],
- [ XPathArgumentRemainder, [ TOK_COMMA, XPathExpr ], -1,
- makeArgumentExpr ],
- [ XPathUnionExpr, [ XPathPathExpr ], 20,
- passExpr ],
- [ XPathUnionExpr, [ XPathUnionExpr, TOK_PIPE, XPathPathExpr ], 20,
- makeUnionExpr ],
- [ XPathPathExpr, [ XPathLocationPath ], 20,
- passExpr ],
- [ XPathPathExpr, [ XPathFilterExpr ], 19,
- passExpr ],
- [ XPathPathExpr,
- [ XPathFilterExpr, TOK_SLASH, XPathRelativeLocationPath ], 19,
- makePathExpr1 ],
- [ XPathPathExpr,
- [ XPathFilterExpr, TOK_DSLASH, XPathRelativeLocationPath ], 19,
- makePathExpr2 ],
- [ XPathFilterExpr, [ XPathPrimaryExpr, XPathPredicate, Q_MM ], 31,
- makeFilterExpr ],
- [ XPathExpr, [ XPathPrimaryExpr ], 16,
- passExpr ],
- [ XPathExpr, [ XPathUnionExpr ], 16,
- passExpr ],
- [ XPathExpr, [ TOK_MINUS, XPathExpr ], -1,
- makeUnaryMinusExpr ],
- [ XPathExpr, [ XPathExpr, TOK_OR, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_AND, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_EQ, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_NEQ, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_LT, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_LE, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_GT, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_GE, XPathExpr ], -1,
- makeBinaryExpr ],
- [ XPathExpr, [ XPathExpr, TOK_PLUS, XPathExpr ], -1,
- makeBinaryExpr, ASSOC_LEFT ],
- [ XPathExpr, [ XPathExpr, TOK_MINUS, XPathExpr ], -1,
- makeBinaryExpr, ASSOC_LEFT ],
- [ XPathExpr, [ XPathExpr, TOK_ASTERISK, XPathExpr ], -1,
- makeBinaryExpr, ASSOC_LEFT ],
- [ XPathExpr, [ XPathExpr, TOK_DIV, XPathExpr ], -1,
- makeBinaryExpr, ASSOC_LEFT ],
- [ XPathExpr, [ XPathExpr, TOK_MOD, XPathExpr ], -1,
- makeBinaryExpr, ASSOC_LEFT ],
- [ XPathLiteral, [ TOK_LITERALQ ], -1,
- makeLiteralExpr ],
- [ XPathLiteral, [ TOK_LITERALQQ ], -1,
- makeLiteralExpr ],
- [ XPathNumber, [ TOK_NUMBER ], -1,
- makeNumberExpr ],
- [ XPathVariableReference, [ TOK_DOLLAR, TOK_QNAME ], 200,
- makeVariableReference ]
- ];
- // That function computes some optimizations of the above data
- // structures and will be called right here. It merely takes the
- // counter variables out of the global scope.
- var xpathRules = [];
- function xpathParseInit() {
- if (xpathRules.length) {
- return;
- }
- // Some simple optimizations for the xpath expression parser: sort
- // grammar rules descending by length, so that the longest match is
- // first found.
- xpathGrammarRules.sort(function(a,b) {
- var la = a[1].length;
- var lb = b[1].length;
- if (la < lb) {
- return 1;
- } else if (la > lb) {
- return -1;
- } else {
- return 0;
- }
- });
- var k = 1;
- for (var i = 0; i < xpathNonTerminals.length; ++i) {
- xpathNonTerminals[i].key = k++;
- }
- for (i = 0; i < xpathTokenRules.length; ++i) {
- xpathTokenRules[i].key = k++;
- }
- xpathLog('XPath parse INIT: ' + k + ' rules');
- // Another slight optimization: sort the rules into bins according
- // to the last element (observing quantifiers), so we can restrict
- // the match against the stack to the subest of rules that match the
- // top of the stack.
- //
- // TODO(mesch): What we actually want is to compute states as in
- // bison, so that we don't have to do any explicit and iterated
- // match against the stack.
- function push_(array, position, element) {
- if (!array[position]) {
- array[position] = [];
- }
- array[position].push(element);
- }
- for (i = 0; i < xpathGrammarRules.length; ++i) {
- var rule = xpathGrammarRules[i];
- var pattern = rule[1];
- for (var j = pattern.length - 1; j >= 0; --j) {
- if (pattern[j] == Q_1M) {
- push_(xpathRules, pattern[j-1].key, rule);
- break;
- } else if (pattern[j] == Q_MM || pattern[j] == Q_01) {
- push_(xpathRules, pattern[j-1].key, rule);
- --j;
- } else {
- push_(xpathRules, pattern[j].key, rule);
- break;
- }
- }
- }
- xpathLog('XPath parse INIT: ' + xpathRules.length + ' rule bins');
- var sum = 0;
- mapExec(xpathRules, function(i) {
- if (i) {
- sum += i.length;
- }
- });
- xpathLog('XPath parse INIT: ' + (sum / xpathRules.length) +
- ' average bin size');
- }
- // Local utility functions that are used by the lexer or parser.
- function xpathCollectDescendants(nodelist, node, opt_tagName) {
- if (opt_tagName && node.getElementsByTagName) {
- copyArray(nodelist, node.getElementsByTagName(opt_tagName));
- return;
- }
- for (var n = node.firstChild; n; n = n.nextSibling) {
- nodelist.push(n);
- xpathCollectDescendants(nodelist, n);
- }
- }
- // DGF extract a tag name suitable for getElementsByTagName
- function xpathExtractTagNameFromNodeTest(nodetest) {
- if (nodetest instanceof NodeTestName) {
- return nodetest.name;
- } else if (/* nodetest instanceof NodeTestAny || */ nodetest instanceof NodeTestElementOrAttribute) {
- // HBC - commented out the NodeTestAny in the above condition; it causes
- // non-element nodes to be excluded! The XPath spec says "node()" must
- // match all node types.
- return "*";
- }
- }
- function xpathCollectDescendantsReverse(nodelist, node) {
- for (var n = node.lastChild; n; n = n.previousSibling) {
- nodelist.push(n);
- xpathCollectDescendantsReverse(nodelist, n);
- }
- }
- // The entry point for the library: match an expression against a DOM
- // node. Returns an XPath value.
- function xpathDomEval(expr, node) {
- var expr1 = xpathParse(expr);
- var ret = expr1.evaluate(new ExprContext(node));
- return ret;
- }
- // Utility function to sort a list of nodes. Used by xsltSort() and
- // nxslSelect().
- function xpathSort(input, sort) {
- if (sort.length == 0) {
- return;
- }
- var sortlist = [];
- for (var i = 0; i < input.contextSize(); ++i) {
- var node = input.nodelist[i];
- var sortitem = { node: node, key: [] };
- var context = input.clone(node, 0, [ node ]);
- for (var j = 0; j < sort.length; ++j) {
- var s = sort[j];
- var value = s.expr.evaluate(context);
- var evalue;
- if (s.type == 'text') {
- evalue = value.stringValue();
- } else if (s.type == 'number') {
- evalue = value.numberValue();
- }
- sortitem.key.push({ value: evalue, order: s.order });
- }
- // Make the sort stable by adding a lowest priority sort by
- // id. This is very convenient and furthermore required by the
- // spec ([XSLT] - Section 10 Sorting).
- sortitem.key.push({ value: i, order: 'ascending' });
- sortlist.push(sortitem);
- }
- sortlist.sort(xpathSortByKey);
- var nodes = [];
- for (var i = 0; i < sortlist.length; ++i) {
- nodes.push(sortlist[i].node);
- }
- input.nodelist = nodes;
- input.setNode(0);
- }
- // Sorts by all order criteria defined. According to the JavaScript
- // spec ([ECMA] Section 11.8.5), the compare operators compare strings
- // as strings and numbers as numbers.
- //
- // NOTE: In browsers which do not follow the spec, this breaks only in
- // the case that numbers should be sorted as strings, which is very
- // uncommon.
- function xpathSortByKey(v1, v2) {
- // NOTE: Sort key vectors of different length never occur in
- // xsltSort.
- for (var i = 0; i < v1.key.length; ++i) {
- var o = v1.key[i].order == 'descending' ? -1 : 1;
- if (v1.key[i].value > v2.key[i].value) {
- return +1 * o;
- } else if (v1.key[i].value < v2.key[i].value) {
- return -1 * o;
- }
- }
- return 0;
- }
- // Parses and then evaluates the given XPath expression in the given
- // input context. Notice that parsed xpath expressions are cached.
- function xpathEval(select, context) {
- var expr = xpathParse(select);
- var ret = expr.evaluate(context);
- return ret;
- }