dom.js

很棒的在线教学系统

         * Runs the supplied method against each item in the Collection/Array.
         * The method is called with the element(s) as the first arg, and the optional param as the second ( method(el, o) ).
         * @method batch
         * @param {String | HTMLElement | Array} el (optional) An element or array of elements to apply the method to
         * @param {Function} method The method to apply to the element(s)
         * @param {Any} o (optional) An optional arg that is passed to the supplied method
         * @param {Boolean} override (optional) Whether or not to override the scope of "method" with "o"
         * @return {Any | Array} The return value(s) from the supplied method
         */
        batch: function(el, method, o, override) {
            el = (el && (el.tagName || el.item)) ? el : Y.Dom.get(el); // skip get() when possible

            if (!el || !method) {
                return false;
            } 
            var scope = (override) ? o : window;
            
            if (el.tagName || el.length === undefined) { // element or not array-like 
                return method.call(scope, el, o);
            } 

            var collection = [];
            
            for (var i = 0, len = el.length; i < len; ++i) {
                collection[collection.length] = method.call(scope, el[i], o);
            }
            
            return collection;
        },
        
        /**
         * Returns the height of the document.
         * @method getDocumentHeight
         * @return {Int} The height of the actual document (which includes the body and its margin).
         */
        getDocumentHeight: function() {
            var scrollHeight = (document.compatMode != 'CSS1Compat') ? document.body.scrollHeight : document.documentElement.scrollHeight;

            var h = Math.max(scrollHeight, Y.Dom.getViewportHeight());
            return h;
        },
        
        /**
         * Returns the width of the document.
         * @method getDocumentWidth
         * @return {Int} The width of the actual document (which includes the body and its margin).
         */
        getDocumentWidth: function() {
            var scrollWidth = (document.compatMode != 'CSS1Compat') ? document.body.scrollWidth : document.documentElement.scrollWidth;
            var w = Math.max(scrollWidth, Y.Dom.getViewportWidth());
            return w;
        },

        /**
         * Returns the current height of the viewport.
         * @method getViewportHeight
         * @return {Int} The height of the viewable area of the page (excludes scrollbars).
         */
        getViewportHeight: function() {
            var height = self.innerHeight; // Safari, Opera
            var mode = document.compatMode;
        
            if ( (mode || isIE) && !isOpera ) { // IE, Gecko
                height = (mode == 'CSS1Compat') ?
                        document.documentElement.clientHeight : // Standards
                        document.body.clientHeight; // Quirks
            }
        
            return height;
        },
        
        /**
         * Returns the current width of the viewport.
         * @method getViewportWidth
         * @return {Int} The width of the viewable area of the page (excludes scrollbars).
         */
        
        getViewportWidth: function() {
            var width = self.innerWidth;  // Safari
            var mode = document.compatMode;
            
            if (mode || isIE) { // IE, Gecko, Opera
                width = (mode == 'CSS1Compat') ?
                        document.documentElement.clientWidth : // Standards
                        document.body.clientWidth; // Quirks
            }
            return width;
        },

       /**
         * Returns the nearest ancestor that passes the test applied by supplied boolean method.
         * For performance reasons, IDs are not accepted and argument validation omitted.
         * @method getAncestorBy
         * @param {HTMLElement} node The HTMLElement to use as the starting point 
         * @param {Function} method - A boolean method for testing elements which receives the element as its only argument.
         * @return {Object} HTMLElement or null if not found
         */
        getAncestorBy: function(node, method) {
            while ( (node = node.parentNode) ) { // NOTE: assignment
                if ( testElement(node, method) ) {
                    return node;
                }
            } 

            return null;
        },
        
        /**
         * Returns the nearest ancestor with the given className.
         * @method getAncestorByClassName
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @param {String} className
         * @return {Object} HTMLElement
         */
        getAncestorByClassName: function(node, className) {
            node = Y.Dom.get(node);
            if (!node) {
                return null;
            }
            var method = function(el) { return Y.Dom.hasClass(el, className); };
            return Y.Dom.getAncestorBy(node, method);
        },

        /**
         * Returns the nearest ancestor with the given tagName.
         * @method getAncestorByTagName
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @param {String} tagName
         * @return {Object} HTMLElement
         */
        getAncestorByTagName: function(node, tagName) {
            node = Y.Dom.get(node);
            if (!node) {
                return null;
            }
            var method = function(el) {
                 return el.tagName && el.tagName.toUpperCase() == tagName.toUpperCase();
            };

            return Y.Dom.getAncestorBy(node, method);
        },

        /**
         * Returns the previous sibling that is an HTMLElement. 
         * For performance reasons, IDs are not accepted and argument validation omitted.
         * Returns the nearest HTMLElement sibling if no method provided.
         * @method getPreviousSiblingBy
         * @param {HTMLElement} node The HTMLElement to use as the starting point 
         * @param {Function} method A boolean function used to test siblings
         * that receives the sibling node being tested as its only argument
         * @return {Object} HTMLElement or null if not found
         */
        getPreviousSiblingBy: function(node, method) {
            while (node) {
                node = node.previousSibling;
                if ( testElement(node, method) ) {
                    return node;
                }
            }
            return null;
        }, 

        /**
         * Returns the previous sibling that is an HTMLElement 
         * @method getPreviousSibling
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @return {Object} HTMLElement or null if not found
         */
        getPreviousSibling: function(node) {
            node = Y.Dom.get(node);
            if (!node) {
                return null;
            }

            return Y.Dom.getPreviousSiblingBy(node);
        }, 

        /**
         * Returns the next HTMLElement sibling that passes the boolean method. 
         * For performance reasons, IDs are not accepted and argument validation omitted.
         * Returns the nearest HTMLElement sibling if no method provided.
         * @method getNextSiblingBy
         * @param {HTMLElement} node The HTMLElement to use as the starting point 
         * @param {Function} method A boolean function used to test siblings
         * that receives the sibling node being tested as its only argument
         * @return {Object} HTMLElement or null if not found
         */
        getNextSiblingBy: function(node, method) {
            while (node) {
                node = node.nextSibling;
                if ( testElement(node, method) ) {
                    return node;
                }
            }
            return null;
        }, 

        /**
         * Returns the next sibling that is an HTMLElement 
         * @method getNextSibling
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @return {Object} HTMLElement or null if not found
         */
        getNextSibling: function(node) {
            node = Y.Dom.get(node);
            if (!node) {
                return null;
            }

            return Y.Dom.getNextSiblingBy(node);
        }, 

        /**
         * Returns the first HTMLElement child that passes the test method. 
         * @method getFirstChildBy
         * @param {HTMLElement} node The HTMLElement to use as the starting point 
         * @param {Function} method A boolean function used to test children
         * that receives the node being tested as its only argument
         * @return {Object} HTMLElement or null if not found
         */
        getFirstChildBy: function(node, method) {
            var child = ( testElement(node.firstChild, method) ) ? node.firstChild : null;
            return child || Y.Dom.getNextSiblingBy(node.firstChild, method);
        }, 

        /**
         * Returns the first HTMLElement child. 
         * @method getFirstChild
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @return {Object} HTMLElement or null if not found
         */
        getFirstChild: function(node, method) {
            node = Y.Dom.get(node);
            if (!node) {
                return null;
            }
            return Y.Dom.getFirstChildBy(node);
        }, 

        /**
         * Returns the last HTMLElement child that passes the test method. 
         * @method getLastChildBy
         * @param {HTMLElement} node The HTMLElement to use as the starting point 
         * @param {Function} method A boolean function used to test children
         * that receives the node being tested as its only argument
         * @return {Object} HTMLElement or null if not found
         */
        getLastChildBy: function(node, method) {
            if (!node) {
                return null;
            }
            var child = ( testElement(node.lastChild, method) ) ? node.lastChild : null;
            return child || Y.Dom.getPreviousSiblingBy(node.lastChild, method);
        }, 

        /**
         * Returns the last HTMLElement child. 
         * @method getLastChild
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @return {Object} HTMLElement or null if not found
         */
        getLastChild: function(node) {
            node = Y.Dom.get(node);
            return Y.Dom.getLastChildBy(node);
        }, 

        /**
         * Returns an array of HTMLElement childNodes that pass the test method. 
         * @method getChildrenBy
         * @param {HTMLElement} node The HTMLElement to start from
         * @param {Function} method A boolean function used to test children
         * that receives the node being tested as its only argument
         * @return {Array} A static array of HTMLElements
         */
        getChildrenBy: function(node, method) {
            var child = Y.Dom.getFirstChildBy(node, method);
            var children = child ? [child] : [];

            Y.Dom.getNextSiblingBy(child, function(node) {
                if ( !method || method(node) ) {
                    children[children.length] = node;
                }
                return false; // fail test to collect all children
            });

            return children;
        },
 
        /**
         * Returns an array of HTMLElement childNodes. 
         * @method getChildren
         * @param {String | HTMLElement} node The HTMLElement or an ID to use as the starting point 
         * @return {Array} A static array of HTMLElements
         */
        getChildren: function(node) {
            node = Y.Dom.get(node);
            if (!node) {
            }

            return Y.Dom.getChildrenBy(node);
        },
 
        /**
         * Returns the left scroll value of the document 
         * @method getDocumentScrollLeft
         * @param {HTMLDocument} document (optional) The document to get the scroll value of
         * @return {Int}  The amount that the document is scrolled to the left
         */
        getDocumentScrollLeft: function(doc) {
            doc = doc || document;
            return Math.max(doc.documentElement.scrollLeft, doc.body.scrollLeft);