treeview.js

一个很不错的...ajax树..支持复选框

        return true;
    },

    /**
     * Deletes this nodes child collection, recursively.  Also collapses
     * the node, and resets the dynamic load flag.  The primary use for
     * this method is to purge a node and allow it to fetch its data
     * dynamically again.
     * @method removeChildren
     * @param {Node} node the node to purge
     */
    removeChildren: function(node) { 
        while (node.children.length) {
            this._deleteNode(node.children[0]);
        }

        node.childrenRendered = false;
        node.dynamicLoadComplete = false;
        if (node.expanded) {
            node.collapse();
        } else {
            node.updateIcon();
        }
    },

    /**
     * Deletes the node and recurses children
     * @method _deleteNode
     * @private
     */
    _deleteNode: function(node) { 
        // Remove all the child nodes first
        this.removeChildren(node);

        // Remove the node from the tree
        this.popNode(node);
    },

    /**
     * Removes the node from the tree, preserving the child collection 
     * to make it possible to insert the branch into another part of the 
     * tree, or another tree.
     * @method popNode
     * @param {Node} the node to remove
     */
    popNode: function(node) { 
        var p = node.parent;

        // Update the parent's collection of children
        var a = [];

        for (var i=0, len=p.children.length;i<len;++i) {
            if (p.children[i] != node) {
                a[a.length] = p.children[i];
            }
        }

        p.children = a;

        // reset the childrenRendered flag for the parent
        p.childrenRendered = false;

         // Update the sibling relationship
        if (node.previousSibling) {
            node.previousSibling.nextSibling = node.nextSibling;
        }

        if (node.nextSibling) {
            node.nextSibling.previousSibling = node.previousSibling;
        }

        node.parent = null;
        node.previousSibling = null;
        node.nextSibling = null;
        node.tree = null;

        // Update the tree's node collection 
        delete this._nodes[node.index];
    },


    /**
     * TreeView instance toString
     * @method toString
     * @return {string} string representation of the tree
     */
    toString: function() {
        return "TreeView " + this.id;
    },

    /**
     * Generates an unique id for an element if it doesn't yet have one
     * @method generateId
     * @private
     */
    generateId: function(el) {
        var id = el.id;

        if (!id) {
            id = "yui-tv-auto-id-" + YAHOO.widget.TreeView.counter;
            ++YAHOO.widget.TreeView.counter;
        }

        return id;
    },

    /**
     * Abstract method that is executed when a node is expanded
     * @method onExpand
     * @param node {Node} the node that was expanded
     * @deprecated use treeobj.subscribe("expand") instead
     */
    onExpand: function(node) { },

    /**
     * Abstract method that is executed when a node is collapsed.
     * @method onCollapse
     * @param node {Node} the node that was collapsed.
     * @deprecated use treeobj.subscribe("collapse") instead
     */
    onCollapse: function(node) { }

};

YAHOO.augment(YAHOO.widget.TreeView, YAHOO.util.EventProvider);

/**
 * Running count of all nodes created in all trees.  This is 
 * used to provide unique identifies for all nodes.  Deleting
 * nodes does not change the nodeCount.
 * @property YAHOO.widget.TreeView.nodeCount
 * @type int
 * @static
 */
YAHOO.widget.TreeView.nodeCount = 0;

/**
 * Global cache of tree instances
 * @property YAHOO.widget.TreeView.trees
 * @type Array
 * @static
 * @private
 */
YAHOO.widget.TreeView.trees = [];

/**
 * Counter for generating a new unique element id
 * @property YAHOO.widget.TreeView.counter
 * @static
 * @private
 */
YAHOO.widget.TreeView.counter = 0;

/**
 * Global method for getting a tree by its id.  Used in the generated
 * tree html.
 * @method YAHOO.widget.TreeView.getTree
 * @param treeId {String} the id of the tree instance
 * @return {TreeView} the tree instance requested, null if not found.
 * @static
 */
YAHOO.widget.TreeView.getTree = function(treeId) {
    var t = YAHOO.widget.TreeView.trees[treeId];
    return (t) ? t : null;
};


/**
 * Global method for getting a node by its id.  Used in the generated
 * tree html.
 * @method YAHOO.widget.TreeView.getNode
 * @param treeId {String} the id of the tree instance
 * @param nodeIndex {String} the index of the node to return
 * @return {Node} the node instance requested, null if not found
 * @static
 */
YAHOO.widget.TreeView.getNode = function(treeId, nodeIndex) {
    var t = YAHOO.widget.TreeView.getTree(treeId);
    return (t) ? t.getNodeByIndex(nodeIndex) : null;
};

/**
 * Add a DOM event
 * @method YAHOO.widget.TreeView.addHandler
 * @param el the elment to bind the handler to
 * @param {string} sType the type of event handler
 * @param {function} fn the callback to invoke
 * @static
 */
YAHOO.widget.TreeView.addHandler = function (el, sType, fn) {
    if (el.addEventListener) {
        el.addEventListener(sType, fn, false);
    } else if (el.attachEvent) {
        el.attachEvent("on" + sType, fn);
    }
};

/**
 * Remove a DOM event
 * @method YAHOO.widget.TreeView.removeHandler
 * @param el the elment to bind the handler to
 * @param {string} sType the type of event handler
 * @param {function} fn the callback to invoke
 * @static
 */

YAHOO.widget.TreeView.removeHandler = function (el, sType, fn) {
    if (el.removeEventListener) {
        el.removeEventListener(sType, fn, false);
    } else if (el.detachEvent) {
        el.detachEvent("on" + sType, fn);
    }
};

/**
 * Attempts to preload the images defined in the styles used to draw the tree by
 * rendering off-screen elements that use the styles.
 * @method YAHOO.widget.TreeView.preload
 * @param {string} prefix the prefix to use to generate the names of the
 * images to preload, default is ygtv
 * @static
 */
YAHOO.widget.TreeView.preload = function(prefix) {
    prefix = prefix || "ygtv";
    var styles = ["tn","tm","tmh","tp","tph","ln","lm","lmh","lp","lph","loading"];

    var sb = [];
    
    for (var i = 0; i < styles.length; ++i) { 
        sb[sb.length] = '<span class="' + prefix + styles[i] + '">&#160;</span>';
    }

    var f = document.createElement("div");
    var s = f.style;
    s.position = "absolute";
    s.top = "-1000px";
    s.left = "-1000px";
    f.innerHTML = sb.join("");

    document.body.appendChild(f);

    YAHOO.widget.TreeView.removeHandler(window, 
                "load", YAHOO.widget.TreeView.preload);

};

YAHOO.widget.TreeView.addHandler(window, 
                "load", YAHOO.widget.TreeView.preload);

/**
 * The base class for all tree nodes.  The node's presentation and behavior in
 * response to mouse events is handled in Node subclasses.
 * @namespace YAHOO.widget
 * @class Node
 * @uses YAHOO.util.EventProvider
 * @param oData {object} a string or object containing the data that will
 * be used to render this node
 * @param oParent {Node} this node's parent node
 * @param expanded {boolean} the initial expanded/collapsed state
 * @constructor
 */
YAHOO.widget.Node = function(oData, oParent, expanded) {
    if (oData) { this.init(oData, oParent, expanded); }
};

YAHOO.widget.Node.prototype = {

    /**
     * The index for this instance obtained from global counter in YAHOO.widget.TreeView.
     * @property index
     * @type int
     */
    index: 0,

    /**
     * This node's child node collection.
     * @property children
     * @type Node[] 
     */
    children: null,

    /**
     * Tree instance this node is part of
     * @property tree
     * @type TreeView
     */
    tree: null,

    /**
     * The data linked to this node.  This can be any object or primitive
     * value, and the data can be used in getNodeHtml().
     * @property data
     * @type object
     */
    data: null,

    /**
     * Parent node
     * @property parent
     * @type Node
     */
    parent: null,

    /**
     * The depth of this node.  We start at -1 for the root node.
     * @property depth
     * @type int
     */
    depth: -1,

    /**
     * The href for the node's label.  If one is not specified, the href will
     * be set so that it toggles the node.
     * @property href
     * @type string
     */
    href: null,

    /**
     * The label href target, defaults to current window
     * @property target
     * @type string
     */
    target: "_self",

    /**
     * The node's expanded/collapsed state
     * @property expanded
     * @type boolean
     */
    expanded: false,

    /**
     * Can multiple children be expanded at once?
     * @property multiExpand
     * @type boolean
     */
    multiExpand: true,

    /**
     * Should we render children for a collapsed node?  It is possible that the
     * implementer will want to render the hidden data...  @todo verify that we 
     * need this, and implement it if we do.
     * @property renderHidden
     * @type boolean
     */
    renderHidden: false,

    /**
     * This flag is set to true when the html is generated for this node's
     * children, and set to false when new children are added.
     * @property childrenRendered
     * @type boolean
     */
    childrenRendered: false,

    /**
     * Dynamically loaded nodes only fetch the data the first time they are
     * expanded.  This flag is set to true once the data has been fetched.
     * @property dynamicLoadComplete
     * @type boolean
     */
    dynamicLoadComplete: false,

    /**
     * This node's previous sibling
     * @property previousSibling
     * @type Node
     */
    previousSibling: null,

    /**
     * This node's next sibling
     * @property nextSibling
     * @type Node
     */
    nextSibling: null,

    /**
     * We can set the node up to call an external method to get the child
     * data dynamically.
     * @property _dynLoad
     * @type boolean
     * @private
     */
    _dynLoad: false,

    /**
     * Function to execute when we need to get this node's child data.
     * @property dataLoader
     * @type function
     */
    dataLoader: null,

    /**
     * This is true for dynamically loading nodes while waiting for the
     * callback to return.
     * @property isLoading
     * @type boolean
     */
    isLoading: false,

    /**
     * The toggle/branch icon will not show if this is set to false.  This
     * could be useful if the implementer wants to have the child contain
     * extra info about the parent, rather than an actual node.
     * @property hasIcon
     * @type boolean
     */
    hasIcon: true,

    /**
     * Used to configure what happens when a dynamic load node is expanded
     * and we discover that it does not have children.  By default, it is
     * treated as if it still could have children (plus/minus icon).  Set
     * iconMode to have it display like a leaf node instead.
     * @property iconMode
     * @type int
     */
    iconMode: 0,

    /**
     * Specifies whether or not the content area of the node should be allowed
     * to wrap.
     * @property nowrap
     * @type boolean
     * @default false
     */
    nowrap: false,

    /**
     * The node type
     * @property _type
     * @private
     */
    _type: "Node",

    /*
    spacerPath: "http://us.i1.yimg.com/us.yimg.com/i/space.gif",
    expandedText: "Expanded",
    collapsedText: "Collapsed",
    loadingText: "Loading",
    */

    /**
     * Initializes this node, gets some of the properties from the parent
     * @method init
     * @param oData {object} a string or object containing the data that will
     * be used to render this node
     * @param oParent {Node} this node's parent node
     * @param expanded {boolean} the initial expanded/collapsed state