I'm trying make some stuff in jQuery using ASP.NET. But the ID from runat="server" is not the same as the id used in HTML.
I used to use this to get the ID from this situation:
$("#<%=txtTest.ClientID%>").val();
But in this case, it does not work. I'm clueless as to why.
Javascript
/* Modal */
function contatoModal() {
//alert("Test");
alert($("#<%=txtTest.ClientID%>").val());
}
HTML
< input runat="server" id="txtTest" value="test" />
Any tips?
<%= txtTest.ClientID %> should work but not in a separate javascript file where server side scripts do not execute. Another possibility is to use a class selector:
<input runat="server" id="txtTest" value="test" class="txtTest" />
and then:
var value = $('.txtTest').val();
In WebForm / HTML Page....
<asp:TextBox ID="txtUserName" runat="server" Class="form-control"></asp:TextBox>
In Jquery
var UserName = $("[id*=txtUserName]").val();
alert(UserName);
100% Sure its Working for me....
As others have mentioned, you can pass a class selector to jQuery, but that is a bit messy. I prefer to use the jQuery attribute ends with selector. Given that a generated ID is a flattened hierarchy of controls, you can use the "ends with" selector to find your element.
<input runat="server" id="txtText" />
When rendered, the generated ID becomes something like this (if within a masterpage's content place holder):
<input id="ctl00_contentplaceholder_txtText" />
To find this control:
$("input[id$='txtText']")
Take caution when using this within a repeater.
Try putting it into a variable name:
var txtTestID = '#' + '<%=txtTest.ClientID %>';
$(txtTestID).val();
I'm not sure if the <%= likes being inside double quotes. I've always had mixed behaviors when not using the single quote.
When using ASP.NET 4 and the ClientIDMode is set to “Predictable”, you can predict the ID based on hierarchy. Or set it set to “Static”, so asp.net wont mess it up.
ScottGu's article on it http://weblogs.asp.net/scottgu/archive/2010/03/30/cleaner-html-markup-with-asp-net-4-web-forms-client-ids-vs-2010-and-net-4-0-series.aspx
And this is extremely useful when using external JS file scenarios.
As Darin Dimitrov said in his answer:
<%= txtTest.ClientID %> should work but not in a separate javascript
file where server side scripts do not execute.
The solutions that I could find for those are:
<input runat="server" id="txtTest" value="test" class="txtTest" />
Use class instead of ID
Using class you can retrieve the value anywhere. This is one of the best solutions (usually the best)
var value = $('.txtTest').val();
Use ClientID code in the aspx
You can always call ClientID in the aspx, but if you are working with some kind of structure, this isn't the best solution. I like to use this method when I'm testing something.
var value = $('#<%=txtTest.ClientID%>').val();
You can also use ClientID in a external js file with a workaround. IT'S NOT PRETTY, use only if you really need it. I usually do this when I use Telerik.
In the aspx:
var id = <%=txtTest.ClientID%>;
In the js file:
var value = $('#'+id).val();
Use Control.ClientIDMode Property Static
so the HTML becomes
<input runat="server" id="txtTest" value="test" ClientIDMode="Static" />
and the js can call it as it is named of
var value = $('#txtTest').val();
The problem with this solution is that you need to be very careful to avoid duplicity on the ids of your page. Try never use Static mode in a controller.
As states MSDN:
The ClientID value is set to the value of the ID property. If the
control is a naming container, the control is used as the top of the
hierarchy of naming containers for any controls that it contains.
The link of shaans's answer is a awesome place to check extra information about ClientIDMode.
Cleaner HTML Markup with ASP.NET 4 Web Forms - Client IDs (VS 2010 and .NET 4.0 Series)
To avoid issues with rendered ID's, use a class instead. This won't change during rendering:
function contatoModal() {
//alert("Test");
alert($(".txtTest").val());
}
HTML:
< input runat="server" id="txtTest" value="test" class="txtText" />
Adding a css class to the input and then using this class in jQuery to getting the input element will solve the issue.
Related
All I want to do is write this string "runat='server'"; in javascript. and use that here:
var dropdown = "<td><asp:DropDownList ID='drpid' runat='server' DataSourceID='SqlDataSource1' DataValueField='Id' DataTextField='Text'></asp:DropDownList></td>"
error is this: SyntaxError: missing ) after argument list
ASP.NET is rendering the control inside your string definition.
The output of that <asp:DropDownList> contains newlines, double quotes, and references to javascript functions, so it will definitely make a mess of your javascript string.
Instead, let asp.net render the dropdown somewhere else (it can even be inside an invisible div) like this :
<div id="hiddenthingContainer" style="display:none;">
<asp:dropdownlist /> ... etc
</div>
Then, either use document.getElementById("hiddenthingContainer") or use jQuery or whatever dom library you prefer to get the element.
once you have it, it becomes a simple matter of getting the contents of the hidden container and presto, there's your string.
example using jQuery :
<div id="hiddenthingContainer" style="display:none">
<asp:DropDownList ID='drpid' runat='server' DataSourceID='SqlDataSource1' DataValueField='Id' DataTextField='Text'></asp:DropDownList>
</div>
<script type="text/javascript">
$(document).ready(function(){
var dropdown = $("#hiddenthingContainer").html()
});
</script>
What's the proper way to go about it. I need it to work like in the example below.
<input type="button" value="Resume" onclick="window.location = '/Test?testid=#(ViewBag.TestID)'" />
I absolutely support Zabavsky's comment that you should use an ActionLink for this specific example in order to have semantically correct markup.
But since you asked:
Mixing razor syntax with Javascript in views
Never do that.
In your view you should have only markup:
<input type="button" value="Resume" id="myButton" data-url="#Url.Action("Test", new { testid = ViewBag.TestID })" />
and javascript (IN A SEPARATE FILE) where you could work with this markup and unobtrusively enhance it:
$(function() {
$('#myButton').click(function() {
window.location.href = $(this).data('url');
});
});
Of course if the user has javascript disabled your web application is completely busted. That's why you should always write semantically correct markup. In this case that would be to use an anchor because in HTML buttons are used to submit forms, anchors are used to redirect to some other location (which is exactly what you are trying to achieve in this specific case).
I would, as Zabavsky said, use an ActionLink for this:
Something like this:
#Html.ActionLink("Resume", "Test", new { testid = ViewBag.TestID })
There are quite a few overrides for actionlink, so you need to pick the one which fits your needs.
The one above output an a href with the text 'Resume' going to action 'Test' on the current controller, passing a routevalue of testid = ViewBag.TestID
You can do it like:
<html><head><script>function newDoc() { window.location.assign("http://www.abc.com") }</script></head><body><input type="button" value="Load new document" onclick="newDoc()"></body></html>
Hope it will help. Thanks.
Well, what you wrote is valid.
You may have VS underline your code in red cause it think you have a js error due to the '' string not ended... but if you run it, it works.
To avoid red underline, you could do :
#{string js = "window.location = '/Test?testid="+ViewBag.TestID+" '";}
<input type="button" value="Resume" onclick="#js" />
Problem: Sometimes you will want to access a component from javascript with
getElementById, but id's are generated dynamically in JSF, so you
need a method of getting an objects id. I answer below on how you can do this.
Original Question:
I want to use some code like below. How can I reference the inputText JSF component in my Javascript?
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<head>
<title>Input Name Page</title>
<script type="javascript" >
function myFunc() {
// how can I get the contents of the inputText component below
alert("Your email address is: " + document.getElementById("emailAddress").value);
}
</script>
</head>
<h:body>
<f:view>
<h:form>
Please enter your email address:<br/>
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
</h:form>
</f:view>
</h:body>
</html>
Update: this post Client Identifiers in JSF2.0 discusses using a technique like:
<script type="javascript" >
function myFunc() {
alert("Your email address is: " + document.getElementById("#{myInptTxtId.clientId}").value);
}
</script>
<h:inputText id="myInptTxtId" value="backingBean.emailAddress"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
Suggesting that the attribute id on the inputText component
creates an object that can be accessed with EL using #{myInptTxtId},
in the above example. The article goes on to state that JSF 2.0 adds
the zero-argument getClientId() method to the UIComponent class.
Thereby allowing the #{myInptTxtId.clientId} construct suggested
above to get the actual generated id of the component.
Though in my tests this doesn't work. Can anyone else confirm/deny.
The answers suggested below suffer from drawback that the above
technique doesn't. So it would be good to know if the above technique
actually works.
You need to use exactly the ID as JSF has assigned in the generated HTML output. Rightclick the page in your webbrowser and choose View Source. That's exactly the HTML code which JS sees (you know, JS runs in webbrowser and intercepts on HTML DOM tree).
Given a
<h:form>
<h:inputText id="emailAddresses" ... />
It'll look something like this:
<form id="j_id0">
<input type="text" id="j_id0:emailAddress" ... />
Where j_id0 is the generated ID of the generated HTML <form> element.
You'd rather give all JSF NamingContainer components a fixed id so that JSF don't autogenerate them. The <h:form> is one of them.
<h:form id="formId">
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
This way the form won't get an autogenerated ID like j_id0 and the input field will get a fixed ID of formId:emailAddress. You can then just reference it as such in JS.
var input = document.getElementById('formId:emailAddress');
From that point on you can continue using JS code as usual. E.g. getting value via input.value.
See also:
How to select JSF components using jQuery?
Update as per your update: you misunderstood the blog article. The special #{component} reference refers to the current component where the EL expression is been evaluated and this works only inside any of the attributes of the component itself. Whatever you want can also be achieved as follows:
var input = document.getElementById('#{emailAddress.clientId}');
with (note the binding to the view, you should absolutely not bind it to a bean)
<h:inputText binding="#{emailAddress}" />
but that's plain ugly. Better use the following approach wherein you pass the generated HTML DOM element as JavaScript this reference to the function
<h:inputText onclick="show(this)" />
with
function show(input) {
alert(input.value);
}
If you're using jQuery, you can even go a step further by abstracting them using a style class as marker interface
<h:inputText styleClass="someMarkerClass" />
with
$(document).on("click", ".someMarkerClass", function() {
var $input = $(this);
alert($input.val());
});
Answer: So this is the technique I'm happiest with. Doesn't require doing too much weird stuff to figure out the id of a component. Remember the whole point of this is so you can know the id of a component from anywhere on your page, not just from the actual component itself. This is key. I press a button, launch javascript function, and it should be able to access any other component, not just the one that launched it.
This solution doesn't require any 'right-click' and see what the id is. That type of solution is brittle, as the id is dynamically generated and if I change the page I'll have to go through that nonsense each time.
Bind the component to a backing bean.
Reference the bound component wherever you want.
So here is a sample of how that can be done.
Assumptions: I have an *.xhtml page (could be *.jsp) and I have defined a backing bean. I'm also using JSF 2.0.
*.xhtml page
<script>
function myFunc() {
var inputText = document.getElementById("#{backBean.emailAddyInputText.clientId}")
alert("The email address is: " + inputText.value );
}
</script>
<h:inputText binding="#{backBean.emailAddyInputText}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
BackBean.java
UIInput emailAddyInputText;
Make sure to create your getter/setter for this property too.
Id is dynamically generated, so you should define names for all parent elements to avoid j_id123-like ids.
Note that if you use jQuery to select element - than you should use double slash before colon:
jQuery("my-form-id\\:my-text-input-block\\:my-input-id")
instead of:
jQuery("my-form-id:my-text-input-block:my-input-id")
In case of Richfaces you can use el expression on jsf page:
#{rich:element('native-jsf-input-id')}
to select javascript element, for example:
#{rich:element('native-jsf-input-id')}.value = "Enter something here";
You can view the HTML source when this is generated and see what the id is set to, so you can use that in your JavaScript. As it's in a form it is probably prepending the form id to it.
I know this is not the JSF way but if you want to avoid the ID pain you can set a special CSS class for the selector. Just make sure to use a good name so that when someone reads the class name it is clear that it was used for this purpose.
<h:inputText id="emailAddresses" class="emailAddressesForSelector"...
In your JavaScript:
jQuery('.emailAddressesForSelector');
Of course you would still have to manually manage class name uniqueness.
I do think this is maintainable as long as you do not use this in reusable components. In that case you could generate the class names using a convention.
<h:form id="myform">
<h:inputText id="name" value="#{beanClass.name}"
a:placeholder="Enter Client Title"> </h:inputText>
</h:form>
This is a small example of jsf. Now I will write javascript code to get the value of the above jsf component:
var x = document.getElementById('myform:name').value; //here x will be of string type
var y= parseInt(x,10); //here we converted x into Integer type and can do the
//arithmetic operations as well
I'm trying make some stuff in jQuery using ASP.NET. But the ID from runat="server" is not the same as the id used in HTML.
I used to use this to get the ID from this situation:
$("#<%=txtTest.ClientID%>").val();
But in this case, it does not work. I'm clueless as to why.
Javascript
/* Modal */
function contatoModal() {
//alert("Test");
alert($("#<%=txtTest.ClientID%>").val());
}
HTML
< input runat="server" id="txtTest" value="test" />
Any tips?
<%= txtTest.ClientID %> should work but not in a separate javascript file where server side scripts do not execute. Another possibility is to use a class selector:
<input runat="server" id="txtTest" value="test" class="txtTest" />
and then:
var value = $('.txtTest').val();
In WebForm / HTML Page....
<asp:TextBox ID="txtUserName" runat="server" Class="form-control"></asp:TextBox>
In Jquery
var UserName = $("[id*=txtUserName]").val();
alert(UserName);
100% Sure its Working for me....
As others have mentioned, you can pass a class selector to jQuery, but that is a bit messy. I prefer to use the jQuery attribute ends with selector. Given that a generated ID is a flattened hierarchy of controls, you can use the "ends with" selector to find your element.
<input runat="server" id="txtText" />
When rendered, the generated ID becomes something like this (if within a masterpage's content place holder):
<input id="ctl00_contentplaceholder_txtText" />
To find this control:
$("input[id$='txtText']")
Take caution when using this within a repeater.
Try putting it into a variable name:
var txtTestID = '#' + '<%=txtTest.ClientID %>';
$(txtTestID).val();
I'm not sure if the <%= likes being inside double quotes. I've always had mixed behaviors when not using the single quote.
When using ASP.NET 4 and the ClientIDMode is set to “Predictable”, you can predict the ID based on hierarchy. Or set it set to “Static”, so asp.net wont mess it up.
ScottGu's article on it http://weblogs.asp.net/scottgu/archive/2010/03/30/cleaner-html-markup-with-asp-net-4-web-forms-client-ids-vs-2010-and-net-4-0-series.aspx
And this is extremely useful when using external JS file scenarios.
As Darin Dimitrov said in his answer:
<%= txtTest.ClientID %> should work but not in a separate javascript
file where server side scripts do not execute.
The solutions that I could find for those are:
<input runat="server" id="txtTest" value="test" class="txtTest" />
Use class instead of ID
Using class you can retrieve the value anywhere. This is one of the best solutions (usually the best)
var value = $('.txtTest').val();
Use ClientID code in the aspx
You can always call ClientID in the aspx, but if you are working with some kind of structure, this isn't the best solution. I like to use this method when I'm testing something.
var value = $('#<%=txtTest.ClientID%>').val();
You can also use ClientID in a external js file with a workaround. IT'S NOT PRETTY, use only if you really need it. I usually do this when I use Telerik.
In the aspx:
var id = <%=txtTest.ClientID%>;
In the js file:
var value = $('#'+id).val();
Use Control.ClientIDMode Property Static
so the HTML becomes
<input runat="server" id="txtTest" value="test" ClientIDMode="Static" />
and the js can call it as it is named of
var value = $('#txtTest').val();
The problem with this solution is that you need to be very careful to avoid duplicity on the ids of your page. Try never use Static mode in a controller.
As states MSDN:
The ClientID value is set to the value of the ID property. If the
control is a naming container, the control is used as the top of the
hierarchy of naming containers for any controls that it contains.
The link of shaans's answer is a awesome place to check extra information about ClientIDMode.
Cleaner HTML Markup with ASP.NET 4 Web Forms - Client IDs (VS 2010 and .NET 4.0 Series)
To avoid issues with rendered ID's, use a class instead. This won't change during rendering:
function contatoModal() {
//alert("Test");
alert($(".txtTest").val());
}
HTML:
< input runat="server" id="txtTest" value="test" class="txtText" />
Adding a css class to the input and then using this class in jQuery to getting the input element will solve the issue.
This is the code from .aspx file
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Login Again</title>
<script type="text/javascript">
function Validate() {
if (document.getElementById("txtLogin").value == "") {
alert("Enter login name.");
}
if (document.getElementById("<%=txtLogin.ClientID%>").value == "") {
alert("Enter login name.");
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:TextBox ID="txtLogin" runat="server"></asp:TextBox>
<asp:Button ID="btnSubmit" runat="server" Text="Login" OnClientClick="Validate()" />
</form>
</body>
</html>
In function Validate() I can
access textbox using Id of control
i.e.; getElementById("txtLogin") so
should I use the second approach
which is accessing control through
control.ClientID and why?
My first understanding was that to
access server control I have to use
this syntax <%= %> but now I come
to know from this example that I can
access server side control simply
through
getElementById("ID-of-control").
The ID generated in the final HTML is not guaranteed to remain the same as the one in your aspx source. When you'll put the controls inside naming containers the ID will have prepended one or several parent ids to ensure its uniqueness. The ClientId property will always give you the final form of the ID attribute as it ends up in the HTML so it's always recommended to use that in your javascript.
Read this....
Quote from post...
All ASP.NET server controls include an
ID property that uniquely identifies
the control and is the means by which
the control is programmatically
accessed in the code-behind class.
Similarly, the elements in an HTML
document may include an id attribute
that uniquely identifies the element;
these id values are often used in
client-side script to programmatically
reference a particular HTML element.
Given this, you may assume that when
an ASP.NET server control is rendered
into HTML, its ID value is used as the
id value of the rendered HTML element.
This is not necessarily the case
because in certain circumstances a
single control with a single ID value
may appear multiple times in the
rendered markup....
Short answer is ClientID to ensure you find your control.
Which version of ASP.NET are you using? In .NET 4 you can specify not to autogenerate the IDs.
I think this is a coincidence in this case because youn are not using any user controls or other containers. Once you do you will no longer be able to guarentee that the controls ID will remain the same and thus you should use the second approach as a best practice because if your page is modified in the ways I have stated your javascript will no longer work and it may be difficult to see why at a later date.