I have a strange problem with Client Side validation after postback. I changed Combobox item that caused Selected Index event to fire(postback occurred). I clicked on 'Save' button after this event. Client side validation is not getting called instead it's calling server side btnSave_Click event.
Client side validation works fine if I don't change ComboBox. I would like to validate page controls on client side before calling server side method. Please let me know.
<asp:TextBox runat="server" ID="txtTitle" />
<telerik:RadComboBox ID="RadComboBox1" runat="server" DataValueField="location_id"
DataTextField="description" OnSelectedIndexChanged="RadComboBox1_SelectedIndexChanged"
AutoPostBack="true" Width="250px" >
</telerik:RadComboBox>
<asp:Button ID="btnSave" name="btnSave" runat="server" Text="Save" OnClick="btnSave_Click" CausesValidation="true"/>
Code behind:
protected void RadComboBox1_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
{
//some logic
}
protected void btnSave_Click(object sender, System.EventArgs e)
{
// save control values
}
Client Script
<script type="JavaScript">
$("#<%=btnSave.ClientID %>").click(function () {
// debugger;
var valid = true;
var errors = false;
var msg;
var msg = "<b>Please fill the Required fields:</b><br />";
if ($("#<%= txtTitle.ClientID %>").val().length == 0) {
msg += "Title is Required!\n";
errors = true;
}
if(errors){
alert(msg);
}
});
});
</script>
Your javascript validation method is doing nothing to stop the postback event from triggering.
Try this:
<script type="JavaScript">
$("#<%=btnSave.ClientID %>").click(function (evt) {
// debugger;
var valid = true;
var errors = false;
var msg;
var msg = "<b>Please fill the Required fields:</b><br />";
if ($("#<%= txtTitle.ClientID %>").val().length == 0) {
msg += "Title is Required!\n";
errors = true;
}
if(errors){
evt.preventDefault();
alert(msg);
return false;
}
});
});
</script>
Because your form controls reside in an UpdatePanel, the postbacks are causing event handlers attached to those controls to be lost. Use jQuery's event delegation to ensure the events still trigger, even after partial postbacks.
Delegated events have the advantage that they can process events from descendant elements that are added to the document at a later time. By picking an element that is guaranteed to be present at the time the delegated event handler is attached, you can use delegated events to avoid the need to frequently attach and remove event handlers.
Change your event handler attachment to something like this:
$('body').on('click', '#<%=btnSave.ClientID %>', function () {
// rest of code
}
I used body as the initial selector, but you can choose any other selector that doesn't reside within the UpdatePanel.
Related
Is it possible to use the onclientclick property of a button to do a clientside check. If the check returns true, then fire the onclick event. If the clientside check returns false, don't fire the onclick event.
Is that possible?
UPDATE:
These 2 work:
Stops the form from submitting:
OnClientClick="return false;"
Allows the form to submit:
OnClientClick="return true;"
The next 2 do not work:
// in js script tag
function mycheck() {
return false;
}
// in asp:button tag
OnClientClick="return mycheck();"
// in js script tag
function mycheck() {
return true;
}
// in asp:button tag
OnClientClick="return mycheck();"
It submits the form both times.
Why is that?
You want to add return inside OnClientClick after a function is called. Otherwise, the button will post back even if function returns false.
<asp:button ID="Button1" runat="server" OnClick="Button1_Click"
OnClientClick="return checkValidation()" Text="Submit" />
<script type="text/javascript">
function checkValidation() {
return confirm('Everything ok?');
}
</script>
Sure. If you use return false within your OnClientClick it will prevent any navigation from happening. So you're code would look like:
<asp:LinkButton runat="server" OnClientClick="if(!ValidatePage()) { return false;}" />
Yes you can, In onclientClick function call use preventDefault()
function onclientClickFun(e)
{
if(!IsValidationSuccess)
{
e.preventDefault();
}
}
OR
function onclientClickFun(e)
{
if(!IsValidationSuccess)
{
return false;
}
}
In the server page create the button:
var button1 = new Button();
button1.ServerClick += new EventHandler(button1_ServerClick);
button1.OnClientClick = SetJsForSaveBtn();
button1.Attributes.Add("UseSubmitBehavior", "false");
panel.Controls.Add(button1 );
//Contains the server code
private void saveBtn_ServerClick(object sender, EventArgs e)
{
//do something if ClientClick returns true
}
//Contains the JS code for the page
LiteralControl js = new LiteralControl();
panel.Controls.Add(js);
js.Text =#"<script type='text/javascript'>
$(document).ready(function(){
function CheckValidationOnClient(){
if(!ValidatePage()){
return false;
}
else{
return true;
}
};
});
</script> ";
private string SetJsForSaveBtn()
{
var jsfunc = #" return CheckValidationOnClient()";
return jsfunc ;
}
I came across this issue too. Did not like to have to put the OnClientClick=return false on every linkbutton. With a simple page it just easier to use an anchor and avoid asp filling the href in for you.
However this is not always possible. So a Simple conclusion is just to inherit the LinkButton and add a variable like AutoPostBack. if false then just override the output with the html or add the OnClientClick in. I dont really like inline tags.
namespace My.WebControls {
[ToolboxData("<{0}:LinkButton runat=server ID=btn></{0}:LinkButton>"), ParseChildren(true), ToolboxItem(true)]
public class LinkButton : System.Web.UI.WebControls.LinkButton {
private bool _postback = true;
[Bindable(true), Category("Behavior"), DefaultValue(true), Description("Gets or Sets the postback click behavior")]
public bool AutoPostBack { get { return _postback; } set { _postback = value; } }
protected override void Render(System.Web.UI.HtmlTextWriter writer) {
if(!AutoPostBack){
this.OnClientClick = "return false";
}
base.Render(writer);
}
}
}
Many attributes should need to be handled in a ViewState but in this case I think we are good;
I am trying to pass parameters to Jquery UI dialog for the new page. The new page has Page_Load method which connects to the database and displays the data. I am having issue with Page_Load method getting called first before $(document).ready. So parameter is empty. I appreciate any suggestions.
MainPage.aspx:
function ShowGraph(sId) {
var oid = sId;
$("#dialog")
.load('Graph.aspx')
.data("sId", sId)
$('#dialog').dialog('open');
}
<div id="dialog" title="My Dialog Title">
</div>
Graph.aspx:
$(document).ready(function () {
$get('<%= HiddenId.ClientID %>').value = $("#dialog").data('sId');
});
<asp:HiddenField runat="server" id="HiddenId"></asp:HiddenField>
code behind
protected void Page_Load(object sender, EventArgs e)
{
BL.GetNumbers(HiddenId.Value);
}
Pass parameter in query string like
function ShowGraph(sId) {
var oid = sId;
$("#dialog")
.load('Graph.aspx?sId='+sId)
$('#dialog').dialog('open');
}
and on page load event you can get it.
Am using the below code to validate and process some other action. In the script, i check the balance amount and pay amount.Pay amount not exceed the balance amount means it return the error message. Then the else part doesn't redirect to my code behind button click event. i can't find it. Please help me to solve this.
if (ddl_selected == "ebal") {
var cust_balance = document.getElementById('<%= lbl_balance.ClientID %>');
var cust_ramount = document.getElementById('<%= lbl_amount.ClientID %>');
if (cust_balance.innerHTML <= cust_ramount .innerHTML) {
alert('Error Alert : You don\'t have enough balance.!.');
return false;
}
else {
return true;
}
}
<asp:ImageButton ID="btn_activate" runat="server" OnClick="btn_pay_Click"
OnClientClick="return valid_details();"
ImageUrl="~/Images/pay.png" />
protected void btn_pay_Click(object sender, ImageClickEventArgs e)
{
//Event not fire
}
Change
OnClientClick="javascript:valid_details();return true;" instead of
OnClientClick="return valid_details();"
Use
OnClientClick="javascript:return valid_details();
instead of
OnClientClick="return valid_details();
I have an aspx master/content page scenario. The parent page has an IFrame which points to a child.aspx. The child.aspx has a checkbox, On page_load of child.aspx, I want to show/hide the checkbox depending on the following logic:
- if the child.aspx is opened directly, then I have to show the checkbox.
- if the child.aspx is opened in the IFrame, then I have to hide the checkbox.
Basically, I want to check in child.aspx, if it contains a parent window then hide the checkbox control otherwise show it.
I will prefer the show/hide code in codebehind in Page_load event as I have to execute some more logic depending on whether the it is opened from parent window or not.
Till now I did the following:
In child.aspx
<asp:Content ID="Content1" ContentPlaceHolderID="Main" Runat="Server">
<script language="javascript" type="text/javascript">
function DoesParentExists()
{
var bool = (parent.location == window.location)? false : true;
var HClientID ='<%=hfDoesParentExist.ClientID%>';
document.getElementById(HClientID).Value = bool;
}
</script>
<div>
<h2>Content - In IFrame</h2>
<asp:HiddenField runat="server" id="hfDoesParentExist" />
<asp:CheckBox ID="chkValid" runat="server" />
<asp:ImageButton ID="ImageButton_FillW8Online" ImageUrl="~/images/expand.gif"
OnClick="btnVerify_Click" runat="server" style="height: 11px" />
</div>
</asp:Content>
in client.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "DoesParentExists", "DoesParentExists()", true);
if (hfDoesParentExist.Value == "true")
{
chkValid.Visible = false;
}
}
Using RegisterClientScriptBlock, I get error in JS. That the object hfDoesParentExist doesn't exist 'coz the control is not yet created. Right? I tried using RegisterStartupScript but in codebehind I always get null in hidden variable. I don't want to use the on button click or something like it. I need it on page_load event only. How to resolve the issue?
This line:
document.getElementById(HClientID).Value = bool;
Should be: (lower case value)
document.getElementById(HClientID).value = bool;
Also you cannot check the value of a hidden field set by javascript register callback, in the current executing context on the server side.
I would move the logic to the client side to hide or show the checkbox. If the field must indeed be removed from the page you can do that as well with javascript.
function DoesParentExists()
{
var bool = (parent.location == window.location)? false : true;
var cehckboxId ='<%=chkValid.ClientID%>';
if(bool){
document.getElementById(cehckboxId).style.display = 'none';
}
else {
document.getElementById(cehckboxId).style.display = 'block';
}
}
You may want to wrap the checkbox with a div and hide the container also to include the label.
To do it server-side, I would rely on a querystring parameter. Have the parent page load the child page by appending ?inframe=1. Then check for that value in your Page_Load.
having a slight problem with an ASP.net page of mine. If a user were to double click on a "submit" button it will write to the database twice (i.e. carry out the 'onclick' method on the imagebutton twice)
How can I make it so that if a user clicks on the imagebutton, just the imagebutton is disabled?
I've tried:
<asp:ImageButton
runat="server"
ID="VerifyStepContinue"
ImageUrl=image src
ToolTip="Go"
TabIndex="98"
CausesValidation="true"
OnClick="methodName"
OnClientClick="this.disabled = true;" />
But this OnClientClick property completely stops the page from being submitted! Any help?
Sorry, yes, I do have Validation controls... hence the icky problem.
Working on this still, up to this point now:
ASP code:
<asp:TextBox ID="hidToken" runat="server" Visible="False" Enabled="False"></asp:TextBox>
...
<asp:ImageButton runat="server" ID="InputStepContinue" Name="InputStepContinue" ImageUrl="imagesrc" ToolTip="Go" TabIndex="98" CausesValidation="true" OnClick="SubmitMethod" OnClientClick="document.getElementById('InputStepContinue').style.visibility='hidden';" />
C# code:
private Random
random = new Random();
protected void Page_Load(object sender, EventArgs e)
{
//Use a Token to make sure it has only been clicked once.
if (Page.IsPostBack)
{
if (double.Parse(hidToken.Text) == ((double)Session["NextToken"]))
{
InputMethod();
}
else
{
// double click
}
}
double next = random.Next();
hidToken.Text = next + "";
Session["NextToken"] = next;
Actually... this nearly works. The double click problem is pretty much fixed (yay!) The image still isn't hidden though.
The general approach is twofold.
Serverside:
On load of the page, generate a token (using System.Random), save it in the session, and write it to a hidden form field
On submit, check that the hidden form field equals the session variable (before setting it again)
Do work
Clientside:
Similar to what you have, but probably just hide the button, and replace it with some text like 'submitting'.
The important thing to note, client side, is that the user may cancel the post by hitting 'escape', so you should consider what to do here (depending on how far along they are the token won't be used, so you'll need to bring the button back from being disabled/hidden).
Complete example follows:
C# (includes code to see it in action):
<html>
<head runat="server">
<title>double-click test</title>
<script language="c#" runat="server">
private Random
random = new Random();
private static int
TEST = 0;
public void Page_Load (object sender, EventArgs ea)
{
SetToken();
}
private void btnTest_Click (object sender, EventArgs ea)
{
if( IsTokenValid() ){
DoWork();
} else {
// double click
ltlResult.Text = "double click!";
}
}
private bool IsTokenValid ()
{
bool result = double.Parse(hidToken.Value) == ((double) Session["NextToken"]);
SetToken();
return result;
}
private void SetToken ()
{
double next = random.Next();
hidToken.Value = next + "";
Session["NextToken"] = next;
}
private void DoWork ()
{
TEST++;
ltlResult.Text = "DoWork(): " + TEST + ".";
}
</script>
</head>
<body>
<script language="javascript">
var last = null;
function f (obj)
{
obj.src = "http://www.gravatar.com/avatar/4659883ec420f39723c3df6ed99971b9?s=32&d=identicon&r=PG";
// Note: Disabling it here produced strange results. More investigation required.
last = obj;
setTimeout("reset()", 1 * 1000);
return true;
}
function reset ()
{
last.src = "http://www.gravatar.com/avatar/495ce8981a5127a9fd24bd72e7e3664a?s=32&d=identicon&r=PG";
last.disabled = "false";
}
</script>
<form id="form1" runat="server">
<asp:HiddenField runat="server" ID="hidToken" />
<asp:ImageButton runat="server" ID="btnTest"
OnClientClick="return f(this);"
ImageUrl="http://www.gravatar.com/avatar/495ce8981a5127a9fd24bd72e7e3664a?s=32&d=identicon&r=PG" OnClick="btnTest_Click" />
<pre>Result: <asp:Literal runat="server" ID="ltlResult" /></pre>
</form>
</body>
</html>
If you have validation on the page, disabling the button client side gets a little tricky. If validation fails, you don't want to disable the button. Here's a snippet that adds the client side event handler:
private void BuildClickOnceButton(WebControl ctl)
{
System.Text.StringBuilder sbValid = new System.Text.StringBuilder();
sbValid.Append("if (typeof(Page_ClientValidate) == 'function') { ");
sbValid.Append("if (Page_ClientValidate() == false) { return false; }} ");
sbValid.Append(ctl.ClientID + ".value = 'Please wait...';");
sbValid.Append(ctl.ClientID + ".disabled = true;");
// GetPostBackEventReference obtains a reference to a client-side script
// function that causes the server to post back to the page.
sbValid.Append(ClientScript.GetPostBackEventReference(ctl, ""));
sbValid.Append(";");
ctl.Attributes.Add("onclick", sbValid.ToString());
}
See this asp.net thread for more info.
Update: the above code would be used to add the OnClientClick handler in code behind. You could also write the javascript in your aspx markup like so:
<script type="text/javascript">
function disableButton(button)
{
// if there are client validators on the page
if (typeof(Page_ClientValidate) == 'function')
{
// if validation failed return false
// this will cancel the click event
if (Page_ClientValidate() == false)
{
return false;
}
}
// change the button text (does not apply to an ImageButton)
//button.value = "Please wait ...";
// disable the button
button.disabled = true;
// fire postback
__doPostBack(button.id, '');
}
</script>
<asp:ImageButton runat="server" ID="VerifyStepContinue" ImageUrl="button.png"
ToolTip="Go" TabIndex="98" CausesValidation="true" OnClick="methodName"
OnClientClick="return disableButton(this);" />
I have solved this by setting a hidden field on the client click before hitting the server.
Then in the server I check the hidden field and if the value is for example something 'FALSE' that might mean I can or cannot of the action.
Similar to Silky's client-side response, I usually make two buttons that look alike except that the second button is disabled and hidden. OnClientClick of the normal button swaps the display styles of the two buttons so that the normal button is hidden and the disabled button is shown.
The double-click feature is a server-side implementation to prevent processing that same request which can be implemented on the client side through JavaScript. The main purpose of the feature is to prevent processing the same request twice. The server-side implementation does this by identifying the repeated request; however, the ideal solution is to prevent this from occurring on the client side.
In the HTML content sent to the client that allows them to submit requests, a small validation JavaScript can be used to check whether the request has already been submitted and if so, prevent the online shopper from submitting the request again. This JavaScript validation function will check the global flag to see if the request has been submitted and, if so; does not resubmit the request. If the double-click feature is disabled on the server, it is highly recommended that the JSP and HTML pages implement this JavaScript prevention.
The following example prevents the form from being submitted more then once by using the onSubmit() action of the form object:
...
<script>
var requestSubmitted = false;
function submitRequest() {
if (!requestSubmitted ) {
requestSubmitted = true;
return true;
}
return false;
}
</script>
...
<FORM method="POST" action="Logon" onSubmit="javascript:submitRequest()">
......
</FORM>
for those who just want to do a quick fix , just hide it and show another button that has no events
<asp:Button ID="RedeemSubmitButton" runat="server" Text="Submit to Redeem" OnClick="RedeemSubmitButton_Click" OnClientClick="hideit();" />
<asp:Button ID="RedeemSubmitButtonDisabled" style="display:none;" runat="server" Text="please wait" OnClientClick="javascript:alert('please wait, processing');" />
<script>
function hideit() {
var btn = $get('<%= this.RedeemSubmitButton.ClientID %>');
var btn2 = $get('<%= this.RedeemSubmitButtonDisabled.ClientID %>');
if (btn != null)
{
btn.style.display = 'none';
btn2.style.display = 'block'
}
}
</script>