selector-beta.js

这是YUI的源码及相关示例。里面有很多很炫的Javascript效果。

    return result;
};

var rTestNode = function(node, selector, token, deDupe) {
    token = token || tokenize(selector).pop() || {};

    if (!node.tagName ||
        (token.tag !== '*' && node.tagName.toUpperCase() !== token.tag) ||
        (deDupe && node._found) ) {
        return false;
    }

    if (token.attributes.length) {
        var attribute;
        for (var i = 0, len = token.attributes.length; i < len; ++i) {
            attribute = node.getAttribute(token.attributes[i][0], 2);
            if (attribute === null || attribute === undefined) {
                return false;
            }
            if ( Selector.operators[token.attributes[i][1]] &&
                    !Selector.operators[token.attributes[i][1]](attribute, token.attributes[i][2])) {
                return false;
            }
        }
    }

    if (token.pseudos.length) {
        for (var i = 0, len = token.pseudos.length; i < len; ++i) {
            if (Selector.pseudos[token.pseudos[i][0]] &&
                    !Selector.pseudos[token.pseudos[i][0]](node, token.pseudos[i][1])) {
                return false;
            }
        }
    }

    return (token.previous && token.previous.combinator !== ',') ?
            combinators[token.previous.combinator](node, token) :
            true;
};


var foundCache = [];
var parentCache = [];
var regexCache = {};

var clearFoundCache = function() {
    for (var i = 0, len = foundCache.length; i < len; ++i) {
        try { // IE no like delete
            delete foundCache[i]._found;
        } catch(e) {
            foundCache[i].removeAttribute('_found');
        }
    }
    foundCache = [];
};

var clearParentCache = function() {
    if (!document.documentElement.children) { // caching children lookups for gecko
        return function() {
            for (var i = 0, len = parentCache.length; i < len; ++i) {
                delete parentCache[i]._children;
            }
            parentCache = [];
        };
    } else return function() {}; // do nothing
}();

var getRegExp = function(str, flags) {
    flags = flags || '';
    if (!regexCache[str + flags]) {
        regexCache[str + flags] = new RegExp(str, flags);
    }
    return regexCache[str + flags];
};

var combinators = {
    ' ': function(node, token) {
        while (node = node.parentNode) {
            if (rTestNode(node, '', token.previous)) {
                return true;
            }
        }  
        return false;
    },

    '>': function(node, token) {
        return rTestNode(node.parentNode, null, token.previous);
    },

    '+': function(node, token) {
        var sib = node.previousSibling;
        while (sib && sib.nodeType !== 1) {
            sib = sib.previousSibling;
        }

        if (sib && rTestNode(sib, null, token.previous)) {
            return true; 
        }
        return false;
    },

    '~': function(node, token) {
        var sib = node.previousSibling;
        while (sib) {
            if (sib.nodeType === 1 && rTestNode(sib, null, token.previous)) {
                return true;
            }
            sib = sib.previousSibling;
        }

        return false;
    }
};

var getChildren = function() {
    if (document.documentElement.children) { // document for capability test
        return function(node, tag) {
            return (tag) ? node.children.tags(tag) : node.children || [];
        };
    } else {
        return function(node, tag) {
            if (node._children) {
                return node._children;
            }
            var children = [],
                childNodes = node.childNodes;

            for (var i = 0, len = childNodes.length; i < len; ++i) {
                if (childNodes[i].tagName) {
                    if (!tag || childNodes[i].tagName.toLowerCase() === tag) {
                        children[children.length] = childNodes[i];
                    }
                }
            }
            node._children = children;
            parentCache[parentCache.length] = node;
            return children;
        };
    }
}();

/*
    an+b = get every _a_th node starting at the _b_th
    0n+b = no repeat ("0" and "n" may both be omitted (together) , e.g. "0n+1" or "1", not "0+1"), return only the _b_th element
    1n+b =  get every element starting from b ("1" may may be omitted, e.g. "1n+0" or "n+0" or "n")
    an+0 = get every _a_th element, "0" may be omitted 
*/
var getNth = function(node, expr, tag, reverse) {
    if (tag) tag = tag.toLowerCase();
    reNth.test(expr);
    var a = parseInt(RegExp.$1, 10), // include every _a_ elements (zero means no repeat, just first _a_)
        n = RegExp.$2, // "n"
        oddeven = RegExp.$3, // "odd" or "even"
        b = parseInt(RegExp.$4, 10) || 0, // start scan from element _b_
        result = [];

    var siblings = getChildren(node.parentNode, tag);

    if (oddeven) {
        a = 2; // always every other
        op = '+';
        n = 'n';
        b = (oddeven === 'odd') ? 1 : 0;
    } else if ( isNaN(a) ) {
        a = (n) ? 1 : 0; // start from the first or no repeat
    }

    if (a === 0) { // just the first
        if (reverse) {
            b = siblings.length - b + 1; 
        }

        if (siblings[b - 1] === node) {
            return true;
        } else {
            return false;
        }

    } else if (a < 0) {
        reverse = !!reverse;
        a = Math.abs(a);
    }

    if (!reverse) {
        for (var i = b - 1, len = siblings.length; i < len; i += a) {
            if ( i >= 0 && siblings[i] === node ) {
                return true;
            }
        }
    } else {
        for (var i = siblings.length - b, len = siblings.length; i >= 0; i -= a) {
            if ( i < len && siblings[i] === node ) {
                return true;
            }
        }
    }
    return false;
};

var getId = function(attr) {
    for (var i = 0, len = attr.length; i < len; ++i) {
        if (attr[i][0] == 'id' && attr[i][1] === '=') {
            return attr[i][2];
        }
    }
};

var getIdTokenIndex = function(tokens) {
    for (var i = 0, len = tokens.length; i < len; ++i) {
        if (getId(tokens[i].attributes)) {
            return i;
        }
    }
    return -1;
};

var patterns = {
    tag: /^((?:-?[_a-z]+[\w-]*)|\*)/i,
    attributes: /^\[([a-z]+\w*)+([~\|\^\$\*!=]=?)?['"]?([^\]]*?)['"]?\]/i,
    //attributes: /^\[([a-z]+\w*)+([~\|\^\$\*!=]=?)?['"]?([^'"\]]*)['"]?\]*/i,
    pseudos: /^:([-\w]+)(?:\(['"]?(.+)['"]?\))*/i,
    combinator: /^\s*([>+~]|\s)\s*/
};

/**
    Break selector into token units per simple selector.
    Combinator is attached to left-hand selector.
 */
var tokenize = function(selector) {
    var token = {},     // one token per simple selector (left selector holds combinator)
        tokens = [],    // array of tokens
        id,             // unique id for the simple selector (if found)
        found = false,  // whether or not any matches were found this pass
        match;          // the regex match

    selector = replaceShorthand(selector); // convert ID and CLASS shortcuts to attributes

    /*
        Search for selector patterns, store, and strip them from the selector string
        until no patterns match (invalid selector) or we run out of chars.

        Multiple attributes and pseudos are allowed, in any order.
        for example:
            'form:first-child[type=button]:not(button)[lang|=en]'
    */
    do {
        found = false; // reset after full pass
        for (var re in patterns) {
                if (!YAHOO.lang.hasOwnProperty(patterns, re)) {
                    continue;
                }
                if (re != 'tag' && re != 'combinator') { // only one allowed
                    token[re] = token[re] || [];
                }
            if (match = patterns[re].exec(selector)) { // note assignment
                found = true;
                if (re != 'tag' && re != 'combinator') { // only one allowed
                    //token[re] = token[re] || [];

                    // capture ID for fast path to element
                    if (re === 'attributes' && match[1] === 'id') {
                        token.id = match[3];
                    }

                    token[re].push(match.slice(1));
                } else { // single selector (tag, combinator)
                    token[re] = match[1];
                }
                selector = selector.replace(match[0], ''); // strip current match from selector
                if (re === 'combinator' || !selector.length) { // next token or done
                    token.attributes = fixAttributes(token.attributes);
                    token.pseudos = token.pseudos || [];
                    token.tag = token.tag ? token.tag.toUpperCase() : '*';
                    tokens.push(token);

                    token = { // prep next token
                        previous: token
                    };
                }
            }
        }
    } while (found);

    return tokens;
};

var fixAttributes = function(attr) {
    var aliases = Selector.attrAliases;
    attr = attr || [];
    for (var i = 0, len = attr.length; i < len; ++i) {
        if (aliases[attr[i][0]]) { // convert reserved words, etc
            attr[i][0] = aliases[attr[i][0]];
        }
        if (!attr[i][1]) { // use exists operator
            attr[i][1] = '';
        }
    }
    return attr;
};

var replaceShorthand = function(selector) {
    var shorthand = Selector.shorthand;
    var attrs = selector.match(patterns.attributes); // pull attributes to avoid false pos on "." and "#"
    if (attrs) {
        selector = selector.replace(patterns.attributes, 'REPLACED_ATTRIBUTE');
    }
    for (var re in shorthand) {
        if (!YAHOO.lang.hasOwnProperty(shorthand, re)) {
            continue;
        }
        selector = selector.replace(getRegExp(re, 'gi'), shorthand[re]);
    }

    if (attrs) {
        for (var i = 0, len = attrs.length; i < len; ++i) {
            selector = selector.replace('REPLACED_ATTRIBUTE', attrs[i]);
        }
    }
    return selector;
};

Selector = new Selector();
Selector.patterns = patterns;
Y.Selector = Selector;

if (YAHOO.env.ua.ie) { // rewrite class for IE (others use getAttribute('class')
    Y.Selector.attrAliases['class'] = 'className';
    Y.Selector.attrAliases['for'] = 'htmlFor';
}

})();
YAHOO.register("selector", YAHOO.util.Selector, {version: "2.6.0", build: "1321"});