jQuery and ASP.NET Control issue - asp.net

If I have a custom ASP.NET control that renders as an html control with an ID, I'm trying to add an attribute to the input control with jQuery.
However, I'm running into some issues:
First, my jQuery is not able to select it.
I have so far:
$(document).ready(function() {
$(client id of the input control).attr('onclick', function () { alert('hey!'); });
});
It seems as if the jQuery is trying to find the input control but cannot.
Any ideas?
UPDATE:
Normally, the solutions presented would work but since this is a SharePoint Publishing .aspx page, Code blocks are not allowed... Trying other work arounds.

Just wire up the click event in jQuery.
$(document).ready(function() {
$(id of the input control)click(function() {
alert('hey!');
});
});
Also, make sure you aren't just putting the ID you typed in to the control in the jQuery. ASP.Net renders the control with a much different ID than you had given the control. On one of the sites I run, I have the following button:
<asp:Button ID="btnSignup" runat="server" Text="Sign Up" />
The ID in the rendered HTML is not btnSignup, it actually renders as ctl00_cpLeft_btnSignup. To select that control with jQuery, you can do this:
$("input[id$='btnSignup'").click(function() { ... });
Edit:
$("input[id$='btnSignup'}").click(function() { ... });
You can also select using:
$("#<%= btnSignup.ClientID %>").click(function() { ... });
Edit:
I looked into using the <%= ... %> method and you would have to have your javascript IN the ASPX/ASCX file itself for it to work. Because of this, I'd stick with the regex method.

What do you use as the ID of the input control?
You have to use the ClientID of the control, not it's ID.

You need to use its ClientID. If your ASP.NET markup looks like this:
<uc:MyControl runat="server" ID="myControl1" />
Your jQuery selector should look like this:
$(document).ready(function() {
$("<%=myControl1.ClientID%>").attr('onclick', function () { alert('hey!'); });
});

Selecting a ASP.NET generated ID with jQuery

Is your ASP.NET control in a master page or a user control? ASP.NET will prepend a bunch of identifiers to your ID to make sure it is unique.
What is the ID of the control coming out as in HTML?

If you're setting the ID of the rendered HTML control to the ID given to the ASP.NET control, you need to be aware of how ASP.NET handles control ID namespaces. Essentially, each control nested within a control needs to always guarantee a unique identifier. ASP.NET maintains this by taking the ID assigned to a control and prepending it with the ID of every control that contains the control. Thus, a control on a page will contain a string of ids going up to the form on the page itself.
You do not want to have to re-construct this client-side. Instead, Control defines ClientID, which will return the ID of the control as rendered on the client. Embed this into your jQuery, or into a javascript variable that your jQuery can see if you are putting the jQuery in a separate script file) and you should be fine.

just to inform you, the document.ready part is not needed, using asp.net control the id is changed to something different then what is expect, a ct100.... is thrown on the beginning of it, so this way will look for the actual id name even though asp.net throws the mangled code on the beginning,because it looks for all elements (*) that have an ID that ends with the specified text.
$(function() {
$("*[id$='idofcontrol']".click(function() { alert('hey!'); });
});
or go to the view source and copy the id name and paste it in your code or just use the css class selector as so:
$(function() {
$('.myclassname').click(function() { alert('hey!'); });
});

Since you mentioned Sharepoint you might be interested in this series on EndUserSharepoint that focuses on integrating jQuery with Sharepoint. The author discusses getting jQuery to manipulate the webparts.

Related

Using Javascript to detect when a user has selected an item in an ASP.NET listbox

I am developing an ASP.NET web application that incorporates google maps. I have an ASP.NET listbox on my page which contains a list of items. When the user selects one of the items, I'd like to show this item on the map. The main complication lies in the fact that google maps uses javascript to control it and the listbox is a server control.
I can think of two ways to do this. The first would involve the listbox calling a javascript function when the user selects a new item. I can then write this function to perform the necessary map operations. Unfortunately, the OnSelectedIndexChanged property of the listbox doesn't seem to support javascript functions.
The second involves wrapping an UpdatePanel around the listbox and getting the listbox to perform a postback. In the SelectedIndexChanged event in VB/C#, I would the need to somehow make a call to a javascript function which would then update the map.
Which solution can I use?
Thanks
--Amr
In your codebehind (in your pageload) just add a javascript handler to the OnChange attribute that points to your javascript function. Eg:
lbYourListBox.Attributes.Add("onChange", "UpdateYourMap();");
You could also add this to your control using inline javascript as well but I prefer to do it in the codebehind so that the framework can handle matching up the names.
You could simply embed javascript into your page, avoidig relying on ASP with it. Put the code into your document body:
<script language="javascript">
body.onload=function(){
var lb=document.getElementById("yourlistboxid");
lb.onChange = function(){
// put your handling code here
}
}
</script>
to demo the other approach, here's a rough guide:
void listbox_SelectedIndexChanged( ... ) {
string js = string.Format("callToMapsFunction({0});", listbox.SelectedValue);
string scriptKey = "mapscript";
ScriptManager.RegisterStartupScript( listbox, typeof(ListBox), scriptKey
, js, true);
}
RegisterStartupScript runs whatever javascript you give it after the partial postback completes. you don't necessarily have to pass the listbox value- just whatever data you want to provide to the maps api. the first 3 items are for preventing the script from registering a bunch of times (as far as I know). the true at the end tells the scriptmanager to automagically add opening and closing tags around your js code.

Access hiddenfield using Jquery

I have a page that's derived from a master page. On this page, I have a hiddenfield ("hfUser"). How can I access this "hfUser" control and get/set its value using JQuery?
I've tried variants of this:
$(document).ready(function() {
var test = $("#hfUser").val();
alert(test);
});
but test = undefined. I'm guessing I've got the selector wrong, but I don't know how to get an asp hiddenfield. Any ideas?
Thanks
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.
ASP does like to mangle ID's. The further down the rabbit hole (or nesting controls) you go, the more ASP adds to your control ID. Throw in Master Pages, and it's yet another level or two.
Another way to access server-side controls (with the runat property set), is to use the square brackets in your jQuery selector.
Like this:
$("[id$='hidImgSource']").val()
That selects any elements whose ID has 'hidImgSource' as ending part of the name. So it will find mangled ID's.
Here is a link to the jQuery Selectors page that explains some more options.
If the hidden field is an ASP.NET control, check out this blog post to help you with jQuery selectors for ASP.NET controls
http://www.foliotek.com/devblog/extending-jquery-to-select-asp-controls/
Do it like this:
$(document).ready(function()
{
var test = $("**#<%= hfUser.ClientID %>**").val();
alert(test);
});

JQuery output a dynamic control in a div

How do I handle the click of a checkbox to show another control preferrably a user conrtrol (ASP.NET ) dynamically.
I don't know anything about the system you're using but the low down dirty way I'd do this is...
Stick the user control on a blank page of it's own.
When the checkbox is clicked, have JQuery go get the HTML content of the page the user control is on and stick it in the div.
This will result in not-so-neat html in the calling page though.
And is this an asp:CheckBox or an html input?
If you want to create a new object, you can do this:
var checkbox = $("<input type='checkbox' ... />");
$('div#someID').append(checkbox);
Though it sounds like you perhaps want to get the data to append from an AJAX call. I can't quite tell from the question.
Assuming you hide the control with CSS by default you could shorten TStamper's code to something like:
$(function() {
$('#checkbox').click(function() {
$('#control').toggle();
});
});
<mycontrol:UC id="control" runat="server" />
I'm partial to using jquery's taconite plugin. It enables you to return multiple controls from a single ajax call.
For a simple show/hide control scenario rendering a hidden control on a page is good enough. If your control is big or changes due to user actions then your best bet is rendering control on the server and using js to update DOM.
If you're using jquery for your DOM updates and wish to find control by id use:
$("[id$=controlId]")
This will locate your control even with asp.net prefixes to the id.
I'm working on a simple c# wrapper for the taconite plugin which should enable you to use the plugin more easily (sample web site coming soon).
Are you looking for something like this:
$(function(){
$('#Control').hide(); //initially hide the control
$('#checkbox').click(function(){ // bind the checkbox click event
if ($('#checkbox').attr('checked')) {
$('#Control').show();
}
});
});
<mycontrol:UC id="Control" runat="server" />

Easiest/Best Hide/Show Client Side Hide/Show for ASP.NET

I have a DropDownList and a TextBox on a Page. When the user chooses the "other" option in the DropDownList I want to display a TextBox just to the right of it. I do not want to use the traditional PostBack technique. I want this interaction to be client side.
I am aware that I can get a get a reference to the DOM element and set its style to "display:none" or "display:". What I am looking for is something that is built into the ASP.NET framework for handling something like this. I mean, in jQuery this is as simple as $('controlID').hide. Is there a Control Extender that can do this? Is jQuery part of the ASP.NET framework yet?
jQuery will be/is distributed with VisualStudio/ASP.NET MVC, though I wouldn't call it part of the framework. I think that you can feel free to use it and trust that it will be supported.
Note that Microsoft has said that they will be using the main line of development for jQuery so the code itself won't be any different than you can download from jQuery.com, except perhaps for built-in Intellisense.
EDIT: To set up your functionality download the code from jquery.com. Put it in your scripts folder, or wherever you store javascript stuff. Add a script reference for it to your page. Use jquery to add an onchange handler to your dropdown list and when the value of the dropdown list is other show the textbox, otherwise hide it. The example below assumes that other isn't the default selection. If you are using runat="server" controls with MasterPages or inside UserControls, you'll need to adjust the names in the javascript functions to account for the name mangling that ASP.NET does. Probably simpler to give them unique CSS classes and reference them using the ".class" notation rather than "#id" notation.
<script type="text/javascript" src="...pathtoscript../jquery.1.2.6.js"></script>
<script type="text/javascript">
$(document).ready( function() {
$("#DropDownListID").bind('change', function() {
if (this.options[this.selectedIndex].value == 'other')
{
$("#TextBoxID").show();
}
else
{
$("#TextBoxID").hide();
}
});
});
</script>
...
<select id="DropDownList">
<option value='first'>First</option>
...
<option value='other'>Other</option>
</select>
<input type='text' id='TextBox' style='display: none;' />
You could also use the asp.net client side framework(via the scriptmanager) to get a reference to the element. But then you still have to use the normal DOM manipulation.
$get('<%= myDropDown.ClientID %>').style.display = 'none';
Just make sure you have the script manager referenced.
For something so simple, I wouldn't think it is worth referencing jquery, but maybe you've got bigger plans ;-)

Get the ASP.NET form name

I'm looking for a way to get the name of the main HTML form so I can submit it from JavaScript.
The reason I can just set the name of the form is because the JavaScript is on a User Control that could get added to many different sites with different form names.
Thanks.
I'm not totally sure that this will address what you're asking for, so please comment on it:
In your script, when the User Control renders, you could have this placed in there. So long as script doesn't have a "runat" attribute, you should be good.
<script type="text/javascript">
var formname = '<%=this.Page.Form.Name %>';
</script>
I'm not sure , try "YourUserControl.Page.Form"
But why do you need the form name, are you going to have more than one form on your .aspx page , if not, you can get the whole post back JS code for the control that will do the post back (submit) using "Page.ClientScript.GetPostBackEventReference()" and use it to set the "OnClick" attribute of whatever you will use to submit the page.
you can't have more than one form control with runat="server" on an aspx page, so you cn use document.forms[0]
<script type="text/javascript">
var formname = '<%=this.Page.AppRelativeVirtualPath.Replace(this.Page.AppRelativeTemplateSourceDirectory,"")%>';
</script>
ASP.NET pages can only have one form, so its safe to just do:
document.forms[0].submit();

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