Get the Value of an asp:HiddenField using jQuery

Question

I have two pages. From the first page, I open a modal with a querystring that holds that value of a client name. I then use this to set a hiddenfield on the modal that opened.

I need a TextBox on the new modal to display the value that has been sent through from the first screen.

I've tried getting the value using:

var hv = $('hidClientField').val();`

But this doesn't seem to work.

This is my hidden field:

<asp:HiddenField ID="hidClientName" runat="server" />`

I set it in the code behind on the Page_Load like this:

hidClientName.Value = Request.QueryString["Client_Name"] ?? "";`

Any ideas will be much appreciated.

Sophrosyne

Answer 1

Try any of the following

1. If ASP.Net control and javascript both are on same page, then use

   var hv = $("#"+ '<%= hidClientField.ClientID %>').val();
   

2. If you want to access the control from some JS file, then

   // 'id$' will cause jQuery to search control whose ID ends with 'hidClientField'
   var hv = $('input[id$=hidClientField]').val();
   

3. You can use class name selector to achieve same. Check out this similar question.

In asp.net, controls id is mangled. Because of this your code is not working.

Hope this works for you.

Labbe

IMO, this way of doing should not be used because when the js code is in a .js external file, the <%...%> won't be parsed. – Tigre

Answer 2

You forgot the # in your selector to select by ID:

var hv = $('#hidClientField').val();

Although asp.net generates ID based on the naming containers so you might end up with an ID like ctl1$hidClientField. You can then use the "attribute ends with" selector:

var hv = $('input[id$=hidClientField]').val();

Check the documentation about jQuery selectors

Tigre

Answer 3

Use ID selector.

var hv = $('#hidClientName').val();

Or

var hv = $('#<%=hidClientName.ClientID%>').val();

Neurosis

Answer 4

Because jQuery knows nothing about asp:HiddenField. It looks in the HTML structure where you have <input type="hidden" name="ctl00$cph_main$HiddenFieldServerDateTime" id="ctl00_cph_main_HiddenFieldServerDateTime" .... So there's no input with ID= HiddenFieldServerDateTime. There are a few ways to overcome this:

• Use a css selector:

  <asp:HiddenField ID="HiddenFieldServerDateTime" 
                   runat="server" 
                   CssClass="SomeStyle" />
  

  with the following selector: var serverDateTime = $(".SomeStyle").val();

  CssClass is not an available class on the HiddenField class (and it doesn't have an Attributes collection, so you can't add it manually).

• Use ClientID property:

  var serverDateTime = $("#<%= HiddenFieldServerDateTime.ClientID %>").val();
  

• Wrap the hidden field in something you can select:

  <div class="date-time-wrap">
    <asp:HiddenField ID="..." runat="server" />
  </div>
  

   

  var serverDateTime = $('.date-time-wrap input[type=hidden]').val();
  

Lingual

How complicate is all that. <%...%> won't work in external javascript files and adding extra markup really is painful. – Tigre

Answer 5

If you are using Asp.net controls, the server will mangle the control ids. It adds a bunch of extraneous control tree hierarchy information into the id. You need to reference what that acutal id is that's getting rendered, which is availble with the ClientID property on the control (hfUser.ClientID) or access your control in a different, more roundabout way, like find the controls parent, then search through its children to find your control.

If you don't have to use the asp.net HiddenField control, try just using a regular old html input.

Lingual

Answer 6

Please try this code.

 var hv = $("#<%= hidClientField.ClientID %>").val();

Colfin

Answer 7

you can do in this way

var hval = $('#<%= hdMarkupPercentage.ClientID%>').val();

Durham

Answer 8

Include ClientIDMode="Static" in your code.

var obj = $('#hidClientName').val(); <asp:HiddenField ID="hidClientName" ClientIDMode="Static" runat="server" />

Or

var obj = $('#<%=hidClientName.ClientID%>').val(); <asp:HiddenField ID="hidClientName" runat="server" />

Lamented