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
Related
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>
I'm using the javascript below to read the value of an asp.net control in the client-side. However, it always returns the null value. I'm using similar code at other pages in my website, but now i can't read this specific control. Please suggest anyways I can fix this problem.
<asp:Label ID="srch_data" runat="server" ClientIDMode="Static" ></asp:Label>
var srch_data = document.getElementById("<%= srch_data.ClientID %>");
alert(srch_data);
Try using single quotes:
var srch_data = document.getElementById('<%= srch_data.ClientID %>').value;
Try this
var srch_data =document.getElementById('srch_data').innerHTML;
ASP.Net Label becomes span after rendering so instead of finding a label which can not be recognized by JS better find
Add the defer attribute to your script element. I tested and it worked.
Try something like below -
<%--defer indicates the script to be run after the document is completely parsed.--%>
<script type="text/javascript" language="javascript" defer="true">
var label = document.getElementById("<%= srch_data.ClientID %>");
alert("label : " + label);
</script>
<asp:Label ID="srch_data" runat="server" ClientIDMode="Static"></asp:Label>
This should fix your issue.
I have a dropdownlist defined:
<asp:DropDownList Width="300px" ID="PlaceHoldersDropDownList" runat="server"
AppendDataBoundItems="True" TabIndex="3" onchange="PasteTextInEditor
(this.options[this.selectedIndex].value), '<%=
SubjectTextBox.ClientID %>'" >
So, I pass the selected text and a textbox ID to a javascript function. The text box is defined as:
<asp:TextBox Width="660px" ID="SubjectTextBox" Text='<%# Bind( "Subject") %>'
runat="server" TabIndex="4" MaxLength="100">
</asp:TextBox>
So, in script function, when i put alert like this :
alert(text); //shows selected value
alert(editor); // shows undefined
So editor value is turning up undefined. So, can you please let me know the mistake I've been doing. I would like to save that value selected from dropdown into textbox.Please help me fixing th eproblem. Thank You
It looks like your bracket is in the wrong place in your "onchange": you're only passing one parameter and not the client id.
But regardless, the ClientID is not going to be parsed here. Instead, I suggest you add your onclick in the code behind, either in your Page_Load or Page_PreRender:
PlaceHoldersDropDownList.Attributes.Add("onchange", "PasteTextInEditor(this.options[this.selectedIndex].value, '" + SubjectTextBox.ClientID + "');")
I have a hidden field in a User Control. At run time I assign the hidden fields ClientId to an anchor tag like this:
aClickSort1.HRef = string.Format("javascript:SortImage({0},{1});", divArrowUp1.ClientID, hiddenSort1.ClientID);
The thing is that when I try to get the hidden fields ClientId in client side code, it is undefined.
How can access it on the client side code?
Ps. The HiddenField is in a usercontrol
Regards Örvar
When you set Visible="false" to server side control, it will not be sent at all to the client.
Instead, set style="display: none;" or even better via CSS then it will be sent to the browser and still be hidden.
It seems that the reason is the non-visible container. If you have something like:
<asp:panel id="panel1" runat="server" Visible="false">
<asp:hiddenfield id="hiddenfield1 runat="server" value="123"/>
</asp:panel>
You cannot access the stuff in panel1 as things are not rendered for server side controls with visible="false" attribute.
You can set it into a div with style="display:none;" or just leave hiddenfield outside the non-visible container as it is not visible anyway.
You need to set hiddenSort1's ClientIdMode to Static.
Like this:
<asp:HiddenField ID="hiddenSort1" runat="server" ClientIDMode="Static" />
From javascript:
var hiddenSort1 = document.getElementById('hiddenSort1');
Correct me if I am wrong, but isn´t the Id generated and if you have the hidden field in a user control it will get the Id of:
myUserControlName$myHiddenFieldId
?
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>