155 lines
4.5 KiB
JavaScript
155 lines
4.5 KiB
JavaScript
// Copyright 2007 The Closure Library Authors. All Rights Reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS-IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
/**
|
|
* @fileoverview DOM pattern to match any children of a tag, and
|
|
* specifically collect those that match a child pattern.
|
|
*
|
|
* @author robbyw@google.com (Robby Walker)
|
|
*/
|
|
|
|
goog.provide('goog.dom.pattern.ChildMatches');
|
|
|
|
goog.require('goog.dom.pattern.AllChildren');
|
|
goog.require('goog.dom.pattern.MatchType');
|
|
|
|
|
|
|
|
/**
|
|
* Pattern object that matches any nodes at or below the current tree depth.
|
|
*
|
|
* @param {goog.dom.pattern.AbstractPattern} childPattern Pattern to collect
|
|
* child matches of.
|
|
* @param {number=} opt_minimumMatches Enforce a minimum nuber of matches.
|
|
* Defaults to 0.
|
|
* @constructor
|
|
* @extends {goog.dom.pattern.AllChildren}
|
|
*/
|
|
goog.dom.pattern.ChildMatches = function(childPattern, opt_minimumMatches) {
|
|
this.childPattern_ = childPattern;
|
|
this.matches = [];
|
|
this.minimumMatches_ = opt_minimumMatches || 0;
|
|
goog.dom.pattern.AllChildren.call(this);
|
|
};
|
|
goog.inherits(goog.dom.pattern.ChildMatches, goog.dom.pattern.AllChildren);
|
|
|
|
|
|
/**
|
|
* Array of matched child nodes.
|
|
*
|
|
* @type {Array.<Node>}
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.matches;
|
|
|
|
|
|
/**
|
|
* Minimum number of matches.
|
|
*
|
|
* @type {number}
|
|
* @private
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.minimumMatches_ = 0;
|
|
|
|
|
|
/**
|
|
* The child pattern to collect matches from.
|
|
*
|
|
* @type {goog.dom.pattern.AbstractPattern}
|
|
* @private
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.childPattern_;
|
|
|
|
|
|
/**
|
|
* Whether the pattern has recently matched or failed to match and will need to
|
|
* be reset when starting a new round of matches.
|
|
*
|
|
* @type {boolean}
|
|
* @private
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.needsReset_ = false;
|
|
|
|
|
|
/**
|
|
* Test whether the given token is on the same level.
|
|
*
|
|
* @param {Node} token Token to match against.
|
|
* @param {goog.dom.TagWalkType} type The type of token.
|
|
* @return {goog.dom.pattern.MatchType} {@code MATCHING} if the token is on the
|
|
* same level or deeper and {@code BACKTRACK_MATCH} if not.
|
|
* @override
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.matchToken = function(token, type) {
|
|
// Defer resets so we maintain our matches array until the last possible time.
|
|
if (this.needsReset_) {
|
|
this.reset();
|
|
}
|
|
|
|
// Call the super-method to ensure we stay in the child tree.
|
|
var status =
|
|
goog.dom.pattern.AllChildren.prototype.matchToken.apply(this, arguments);
|
|
|
|
switch (status) {
|
|
case goog.dom.pattern.MatchType.MATCHING:
|
|
var backtrack = false;
|
|
|
|
switch (this.childPattern_.matchToken(token, type)) {
|
|
case goog.dom.pattern.MatchType.BACKTRACK_MATCH:
|
|
backtrack = true;
|
|
case goog.dom.pattern.MatchType.MATCH:
|
|
// Collect the match.
|
|
this.matches.push(this.childPattern_.matchedNode);
|
|
break;
|
|
|
|
default:
|
|
// Keep trying if we haven't hit a terminal state.
|
|
break;
|
|
}
|
|
|
|
if (backtrack) {
|
|
// The only interesting result is a MATCH, since BACKTRACK_MATCH means
|
|
// we are hitting an infinite loop on something like a Repeat(0).
|
|
if (this.childPattern_.matchToken(token, type) ==
|
|
goog.dom.pattern.MatchType.MATCH) {
|
|
this.matches.push(this.childPattern_.matchedNode);
|
|
}
|
|
}
|
|
return goog.dom.pattern.MatchType.MATCHING;
|
|
|
|
case goog.dom.pattern.MatchType.BACKTRACK_MATCH:
|
|
// TODO(robbyw): this should return something like BACKTRACK_NO_MATCH
|
|
// when we don't meet our minimum.
|
|
this.needsReset_ = true;
|
|
return (this.matches.length >= this.minimumMatches_) ?
|
|
goog.dom.pattern.MatchType.BACKTRACK_MATCH :
|
|
goog.dom.pattern.MatchType.NO_MATCH;
|
|
|
|
default:
|
|
this.needsReset_ = true;
|
|
return status;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Reset any internal state this pattern keeps.
|
|
* @override
|
|
*/
|
|
goog.dom.pattern.ChildMatches.prototype.reset = function() {
|
|
this.needsReset_ = false;
|
|
this.matches.length = 0;
|
|
this.childPattern_.reset();
|
|
goog.dom.pattern.AllChildren.prototype.reset.call(this);
|
|
};
|