asp.net treeview checkbox selection

Question

I have several parent nodes. Each parent nodes contains a list of child nodes. My showcheckboxes are set to all.

My question :

On the client side, when I check the parent node - how can I check all the child nodes without doing a post back or using ajax.

Regards

Answer 1

tv.Attributes.Add("onclick", "OnTreeClick(event)");

Add this javascript code

<script language="javascript" type="text/javascript">
    function OnTreeClick(evt) {
        var src = window.event != window.undefined ? window.event.srcElement : evt.target;
        var isChkBoxClick = (src.tagName.toLowerCase() == "input" && src.type == "checkbox");
        if (isChkBoxClick) {
            var parentTable = GetParentByTagName("table", src);
            var nxtSibling = parentTable.nextSibling;
            if (nxtSibling && nxtSibling.nodeType == 1)//check if nxt sibling is not null & is an element node
            {
                if (nxtSibling.tagName.toLowerCase() == "div") //if node has children
                {
                    //check or uncheck children at all levels
                    CheckUncheckChildren(parentTable.nextSibling, src.checked);
                }
            }
            //check or uncheck parents at all levels
            CheckUncheckParents(src, src.checked);
        }
    }

    function CheckUncheckChildren(childContainer, check) {
        var childChkBoxes = childContainer.getElementsByTagName("input");
        var childChkBoxCount = childChkBoxes.length;
        for (var i = 0; i < childChkBoxCount; i++) {
            childChkBoxes[i].checked = check;
        }
    }

    function CheckUncheckParents(srcChild, check) {
        var parentDiv = GetParentByTagName("div", srcChild);
        var parentNodeTable = parentDiv.previousSibling;

        if (parentNodeTable) {
            var checkUncheckSwitch;

            if (check) //checkbox checked
            {
                var isAllSiblingsChecked = AreAllSiblingsChecked(srcChild);
                if (isAllSiblingsChecked)
                    checkUncheckSwitch = true;
                else
                    return; //do not need to check parent if any(one or more) child not checked
            }
            else //checkbox unchecked
            {
                checkUncheckSwitch = false;
            }

            var inpElemsInParentTable = parentNodeTable.getElementsByTagName("input");
            if (inpElemsInParentTable.length > 0) {
                var parentNodeChkBox = inpElemsInParentTable[0];
                parentNodeChkBox.checked = checkUncheckSwitch;
                //do the same recursively
                CheckUncheckParents(parentNodeChkBox, checkUncheckSwitch);
            }
        }
    }

    function AreAllSiblingsChecked(chkBox) {
        var parentDiv = GetParentByTagName("div", chkBox);
        var childCount = parentDiv.childNodes.length;
        for (var i = 0; i < childCount; i++) {
            if (parentDiv.childNodes[i].nodeType == 1) //check if the child node is an element node
            {
                if (parentDiv.childNodes[i].tagName.toLowerCase() == "table") {
                    var prevChkBox = parentDiv.childNodes[i].getElementsByTagName("input")[0];
                    //if any of sibling nodes are not checked, return false
                    if (!prevChkBox.checked) {
                        return false;
                    }
                }
            }
        }
        return true;
    }

    //utility function to get the container of an element by tagname
    function GetParentByTagName(parentTagName, childElementObj) {
        var parent = childElementObj.parentNode;
        while (parent.tagName.toLowerCase() != parentTagName.toLowerCase()) {
            parent = parent.parentNode;
        }
        return parent;
    }

</script>

Answer 2

Great solution above, thanks a lot. I changed the Method CheckUncheckParents() to my preferences: When one of the childnode is checked, the parentnode will be also checked.

function OnTreeClick(evt) {
    var src = window.event != window.undefined ? window.event.srcElement : evt.target
    var isChkBoxClick = (src.tagName.toLowerCase() == "input" && src.type == "checkbox");
    if (isChkBoxClick) {
        var parentTable = GetParentByTagName("table", src);
        var nxtSibling = parentTable.nextSibling;
        if (nxtSibling && nxtSibling.nodeType == 1)//check if nxt sibling is not null & is an element node
        {
            if (nxtSibling.tagName.toLowerCase() == "div") //if node has children
            {
                //check or uncheck children at all levels
                CheckUncheckChildren(parentTable.nextSibling, src.checked);
            }
        }
        //check or uncheck parents at all levels
        CheckUncheckParents(src, src.checked);
    }
}

function CheckUncheckChildren(childContainer, check) {
    var childChkBoxes = childContainer.getElementsByTagName("input");
    var childChkBoxCount = childChkBoxes.length;
    for (var i = 0; i < childChkBoxCount; i++) {
        childChkBoxes[i].checked = check;
    }
}

function CheckUncheckParents(srcChild, check) {
    var parentDiv = GetParentByTagName("div", srcChild);
    var parentNodeTable = parentDiv.previousSibling;

    if (parentNodeTable) {
        var checkUncheckSwitch;

        if (check) //checkbox checked
        {
            checkUncheckSwitch = true;
        }
        else //checkbox unchecked
        {
            var isAllSiblingsUnChecked = AreAllSiblingsUnChecked(srcChild);
            if (!isAllSiblingsUnChecked)
                checkUncheckSwitch = true;
            else
                checkUncheckSwitch = false;
        }

        var inpElemsInParentTable = parentNodeTable.getElementsByTagName("input");
        if (inpElemsInParentTable.length > 0) {
            var parentNodeChkBox = inpElemsInParentTable[0];
            parentNodeChkBox.checked = checkUncheckSwitch;
            //do the same recursively
            CheckUncheckParents(parentNodeChkBox, checkUncheckSwitch);
        }
    }
}

function AreAllSiblingsUnChecked(chkBox) {
    var parentDiv = GetParentByTagName("div", chkBox);
    var childCount = parentDiv.childNodes.length;
    for (var i = 0; i < childCount; i++) {
        if (parentDiv.childNodes[i].nodeType == 1) //check if the child node is an element node
        {
            if (parentDiv.childNodes[i].tagName.toLowerCase() == "table") {
                var prevChkBox = parentDiv.childNodes[i].getElementsByTagName("input")[0];
                //if any of sibling nodes are not checked, return false
                if (prevChkBox.checked) {
                    return false;
                }
            }
        }
    }
    return true;
}

//utility function to get the container of an element by tagname
function GetParentByTagName(parentTagName, childElementObj) {
    var parent = childElementObj.parentNode;
    while (parent.tagName.toLowerCase() != parentTagName.toLowerCase()) {
        parent = parent.parentNode;
    }
    return parent;
}