Finding an asp:button and asp:textbox in Javascript - javascript

What I'm trying to do is get an asp:button to click. The only problem is that it is within a few tags.
Example:
<loginview>
<asp:login1>
<logintemplate>
//asp:textbox and asp:button are located here.
</loginview>
</asp:login>
</logintemplate>
So how would I get javascript to point to that location so that I can manipulate it. For example, get the button to click.

First, you need to figure out which template is being used, since you can only access the active one. (Anonymous or LoggedIn). Once you do that, use the FindControl method on the LoginView to find the ClientID of the element you need to reference.
For example:
<form runat="server">
<asp:LoginView runat="server" ID="LoginView">
<AnonymousTemplate>
<asp:Button ID="ASPButton" Text="Button" runat="server" />
</AnonymousTemplate>
</asp:LoginView>
</form>
<script type="text/javascript">
var el = document.getElementById('<%= LoginView.FindControl("ASPButton").ClientID %>');
</script>

Check out the jQuery framework: you can find controls by ID, and then call methods/properties on those controls.
http://jquery.com/

Related

Set asp.net textbox value using javascript

I want to set the value of a asp.net textbox using javascript
My JS Code is:
document.getElementById('<%=txtFlag.ClientID %>').value = "Track";
My textbox is:
<asp:TextBox ID="txtFlag" runat="server" Visible="False"></asp:TextBox>
But it gives me an error document.getElementById(...)' is null or not an object
I dont understand what is wrong.
Please help.
<asp:TextBox ID="txtFlag" runat="server" Visible="False"></asp:TextBox>
Setting visible=false will cause this textbox to not appear in the rendered page. Remove this, and add display:none;
<asp:TextBox ID="txtFlag" runat="server" style="display:none;"></asp:TextBox>
Try including the ClientIDMode property in your textbox
<asp:TextBox ID="txtFlag" runat="server" Visible="False"
ClientIDMode="Static"></asp:TextBox>
You are calling javascript before complete document load. Please write your javascript code on document.ready function like this
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script type="text/javascript">
$(document).ready(function() {
document.getElementById('<%=txtFlag.ClientID %>').value = "Track";
});
</script>
And second thing is that use display none in place of visible false or use hidden field control
<asp:TextBox ID="txtFlag" runat="server" style="display:none;"></asp:TextBox>
Solution 1:
Make that textbox as visible=true and try,
When you make a control as visible false, that control will not be loaded in client side and as you knew javascript will be executed on client side itself.
Solution 2:
Add this javascript at the end of the page.
document.getElementById('txtFlag').value='Track'
try this

Javascript-error on finding object

im stuck with Javascript in Asp.net...
I made a TextBox named tbValidFrom and another named tbValidTo.
I also made two ModalPopups.
Then i try to open the ModalPopupExtenders when the TextBoxes get focus:
<script type="text/javascript">
$('#tbValidTo').focus(function () {
$find('ModalPopupExtenderNV1').show();
})
$('#tbValidFrom').focus(function () {
$find('ModalPopupExtenderNV2').show();
})
</script>
but it doesnt finds tbValidTo or ModalPopUpExtender ?
Runtime-Error in Microsoft JScript: Object expected
Here is one of the two ModalPopupExtenders and TextBoxes:
<asp:TextBox ID="tbValidFrom" runat="server"></asp:TextBox>
<asp:UpdatePanel ID="UpdatePanelNV2" runat="server" RenderMode="Inline" UpdateMode="Conditional">
<ContentTemplate>
<cc1:ModalPopupExtender ID="ModalPopupExtenderNV2" runat="server" TargetControlID="HiddenField6"
PopupControlID="PanelNewVersion" BackgroundCssClass="modalBackground" BehaviorID="ModalPopupExtenderNV2"
Enabled="True" />
<asp:HiddenField ID="HiddenField6" runat="server" />
</ContentTemplate
</asp:UpdatePanel>
The same as above is with the other ModalPopupExtender and TextBox...
Help would be really nice.
Thanks
Edit: Yes i use a masterpage!
Fails where it is marked yellow.
your jQuery syntax is wrong.
change your script to:
<script type="text/javascript">
$('#tbValidTo').focus(function () {
$(this).find('#<%=ModalPopupExtenderNV1.ClientID%>').show();
});
$('#tbValidFrom').focus(function () {
$(this).find('#<%=ModalPopupExtenderNV2.ClientID%>').show();
})
</script>
elements that has runat="server" will eventually end with a different ID than you entered in the aspx file.
i used the <%= %> to get the 'final' id.
hope that helps
Seeing that markup there is two chances for the issues.
With the ModalPopupExtender.
Where you have given the panel "PanelNewVersion" . Seems like its missing in the markup.
In the Javascript code. If you want to hide that Popup, give the name of the panel. NOt the name of the ModalPopupextender.
Also you have given an update panel there in page, so you can easily handle the modalpopup in any srever side event of your textbox.
Otherwise, if you want to use the Modal popup ijn client side, use jQuery Modalpopup. That will the better option.
ASP.NET Can modify the ID's of elements, if you use a Masterpage the element id's will be modified to something like the following : ctl001_ContentPlaceHolder1_tbValidFrom
To get around this ASP.NET modification of your elements you can use ASP.NET Inline Expressions to get the rendered ID from the object.
See the answer to the following question for more information on ASP.NET Inline Expressions
You can look at changing the Client ID Mode (The way ASP.NET Modifies IDs when the page is rendered) here :
ASP.NET Client ID Modes
EDIT :
The AjaxControlToolkit's ModalPopupExtender is not rendered on the page as a html element, therefore you cannot find this item using the ClientID of the ModalPopupExtender.
You must use the BehaviourID to call the show function on.
The below code should work correctly :
$('#<%= tbValidTo.ClientID %>').focus(function () {
$find('ModalPopupExtenderNV1').show();
})
$('#<%= tbValidFrom.ClientID %>').focus(function () {
$find('ModalPopupExtenderNV2').show();
});
This will find the textbox object using the ASP.NET Inline expressions to find the client ID and will then find the behaviour ID and execute the Show method.
Example Markup :
<script type="text/javascript">
$(document).ready(function() {
$('#<%= tbValidFrom.ClientID %>').focus(function () {
$find('ModalPopupExtenderNV2').show();
});
});
</script>
<asp:TextBox ID="tbValidFrom" runat="server"></asp:TextBox>
<asp:UpdatePanel ID="UpdatePanelNV2" runat="server" RenderMode="Inline" UpdateMode="Conditional">
<ContentTemplate>
<cc1:modalpopupextender id="ModalPopupExtenderNV2" runat="server" targetcontrolid="HiddenField6"
popupcontrolid="PanelNewVersion" backgroundcssclass="modalBackground" behaviorid="ModalPopupExtenderNV2"
enabled="True" />
<asp:HiddenField ID="HiddenField6" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:Panel ID="PanelNewVersion" runat="server">
testing panel
</asp:Panel>

OnClientClick event in In ASP.NET

I'm using ASP.NET to pass a value to a JavaScript function and, for some reason I haven't been able to determine, it isn't working when I try to pass in a value from another control. Instead, it acts like there is a syntax error and it just submits back to the main form.
Does anyone know why?
Example:
<asp:TextBox ID="txtToSay" runat="server" Text="Something"></asp:TextBox>
<asp:Button runat="server" ID="btnSaySomething1" Text="Say Something"
OnClientClick="saySomething(<%=txtToSay.Text%>);" /> <!-- doesn't work -->
<asp:Button runat="server" ID="btnSaySomething1" Text="Say Something"
OnClientClick="saySomething('<%=txtToSay.Text%>');" /> <!-- doesn't work -->
<asp:Button runat="server" ID="btnSaySomething2" Text="Say Something"
OnClientClick="saySomething('Something');" /> <!-- works -->
<script type="text/javascript">
function saySomething(txt){
alert(txt);
};
</script>
Additional Information:
Web Application running on .NET 4.0
Language: C#
Update:
After working with this a while, I've determined that you can't use <%%> tags in ASP controls. Additionally, if you're looking for dynamic evaluation of control values AVOID AVOID AVOID using <%=someControl.Text%> or similar constructs since they are only evaluated once a request is submitted to the server. If you need a static value from another control at runtime, simply set that value in the page load event or handle it another way in the code behind.
Javacript will search for variable name = txtToSay.Text in saySomething function call, Put quotes around it to make it string value
Change
OnClientClick="saySomething(<%=txtToSay.Text%>);"
To
OnClientClick="saySomething('<%=txtToSay.Text%>');"
You can get the txtToSay.Text without passing it this way
<script type="text/javascript">
function saySomething(txt){
alert(document.getElementById('<%=txtToSay.Text%>').value);
};
</script>
you need to put ' around your text in the saySomething() call.
Like this:
<asp:Button runat="server" ID="btnSaySomething1" Text="Say Something" OnClientClick="saySomething('<%=txtToSay.Text%>');" />
UPDATE
<%= %> won't work inside an asp.net control. Can you set it from the code-behind?
I.E
btnSaySomething1.OnClientClick = "Text to say"

$find() return null for defined ajax behaviour

All,
Environment: ASP.NET 2.0, AjaxToolkit build 1.0.20229.0, IE9
I am using $find() to find a behaviour of a call out extender so I can show explicitly using .show() method. Unfortunately, $find() returns null.
$find('my auto generated behvaiour Id').show();
FYI: The BehaviorID on the ValidatorCalloutExtender is generated using ClientID of the control (ClientID_ + "BehaviourID" <- is also what I use in my $find() function) because I have many instances of this control on the same page.
I looked at the rendered code and I can see JS to create that creates the behaviour:
Sys.Application.add_init(function() {
$create(AjaxControlToolkit.ValidatorCalloutBehavior ...
The $find() executes AFTER a postback in an UpdatePanel and returns always null.
EDIT (ADDED):
I created new page and below is the code, find() returns still null,- is there a bug in Ajax control tooklit for ASP.NET 2.0?
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScripManager1" runat="server" EnablePageMethods="True" >
</asp:ScriptManager>
<asp:TextBox runat="server" ID="txtInputField" />
<asp:RequiredFieldValidator runat="server" ID="valInput"
ControlToValidate="txtInputField"
ErrorMessage="ERROR STRING"
Display="none" /> <ajaxToolkit:ValidatorCalloutExtender runat="server" ID="extValInput" TargetControlID="valInput" BehaviorID="myID" />
<asp:Button runat="server" ID="btn" OnClick="btn_click" CausesValidation="True" />
<script type="text/javascript">
var obj = $find("myID");
alert(obj);
</script>
</form>
ADDED:
After observation in JS debugger, I realized that the validator callout extender only appears (is added dynamically to the DOM) when there's error, hence, if there's no error you cannot find it.
THE QUESTION NOW IS: How to reposition the call out extender baloon before displaying it? It is really catch 22, you can't access it when it is not displayed and when it is displayed, it is already to late because it displays in the wrong place.
The cause of the problem is that you try to find component before page completes component initialization. Try to access your editor in Sys.Application.add_load event handler. I tried the following code and everything works fine:
<script type="text/javascript">
Sys.Application.add_load(function() {
var obj = $find("myID");
alert(obj);
});
</script>
Edit:
To address your latest question: how you can reposition it. Callout ValidatorCalloutExtender uses PopupExtender to show it. So, you can try to bind to 'showing' and 'shown' events of the popup extender and then try to reposition callout.
<script type="text/javascript">
Sys.Application.add_load(function() {
var callouotComponent = $find("myID");
var popupBehavior = callouotComponent._popupBehavior;
popupBehavior.add_showing(function(){alert("I am showing");});
popupBehavior.add_shown(function(){alert("I was shown");});
});
</script>
Note: I didn't verify this code, but it can be used as start point.
Modified your code and verified, popup position is changing.
<script type="text/javascript">
Sys.Application.add_load(function () {
var callouotComponent = $find("myID");
//Below line is to init popup ballon, otherwise popup behaviour will return null
callouotComponent._ensureCallout();
var popupBehavior = callouotComponent._popupBehavior;
popupBehavior.set_x(100);
popupBehavior.set_y(100);
});
</script>

Populate a TextBox from a DropDownList selection ASP.NET/Javascript

I have a DDL and ASP.NET Textbox. I would like to populate the text box with the option I choose from the DDL. I need this to be instant and not use postbacks so it would seem JavaScript would be the obvious choice here. I have done quite a bit of searching but everything I have found seems to be for standard HTML (Selects and Inputs) and these do not appear to work with ASP objects:
<asp:DropDownList runat="server" ID="DDLSalesPerson" DataValueField="keyid" DataTextField="FullName" />
<asp:TextBox runat="server" id="txtSalesPerson" />
My DDL is populated from SQL in the code-behind page.
Can somebody assist with the appropriate code I should use? Thanks.
ASP.Net controls render as standard HTML elements on the browser. In script, you can get a reference to them by using the ClientID property of the ASP.Net control.
Put this in a script block in your aspx:
var ddl = document.getElementById('<%=DDLSalesPerson.ClientID %>');
var textBox = document.getElementById('<%= txtSalesPerson.ClientID%>');
Now you have references to the DOM objects for the select and input elements that the ASP.Net controls rendered and you can use the techniques you've already learned on the HTML elements.
Additional info
You need to add an onchange attribute to your DropDownList control as such:
<asp:DropDownList runat="server" ID="DDLSalesPerson" DataValueField="keyid" onchange="ddlChange();" DataTextField="FullName" />
and then put this script block in your aspx
<script type="text/javascript">
function ddlChange()
{
var ddl = document.getElementById('<%=DDLSalesPerson.ClientID %>');
var textBox = document.getElementById('<%= txtSalesPerson.ClientID%>');
textBox.value = ddl.options[ddl.selectedIndex].text;
}
</script>
As you change the dropdown list, you'll see the textbox update. Tested in IE and Chrome.
Since you've pointed out that you're a JavaScript beginner, may i suggest you use an updatepanel control. An updatepanel allows you to execute server code without refreshing the page. Simply place the dropdownList and the textbox in the same updatepanel or in two separate updatepanels and write the code for the textbox to update based on the dropdownlist selection. Make sure to set the dropdownlist to do autopostback.
The asp markup is as follows:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:DropDownList ID="ddlList" runat="server"
AutoPostBack="True">
<asp:ListItem>-select-</asp:ListItem>
<asp:ListItem>option 1</asp:ListItem>
<asp:ListItem>option 2</asp:ListItem>
</asp:DropDownList>
<asp:TextBox ID="txtTextBox" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
The codebehind in vb is as follows:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If ddlList.Text <> "-select-" then
txtTextBox.Text = ddlList.text
End If
End Sub
If you're new to JavaScript, use the jQuery library (simply provide references to the CDN-hosted jQUery files at google.com) and then you can use the following code:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
<script language="javascript" type="text/javascript">
$("#DDLSalesPerson").change(function () {
$("#txtSalesPerson").val($(this).val());
});
</script>

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