I installed jQuery to be able to use its DatePicker and it works well. But whenever I try to debug my ASP.NET MVC website in Visual Studio I get mutliple "$ is undefined" errors popping up as it tries to run jQuery in the javascript code. I've searched
other messages about this error and no one solution seems to stand out.
When I installed jQuery it loaded my script folder with about 2 million .js files. OK, it's not 2 million. It's only about 10. The examples I found said this is what I need to include to get it to run and that's what I have used:
This is running in a master layout page that is called from _ViewStart.cshtml. Is that part of the problem? I tried taking out the tildes, I tried adding a reference to jquery-1.5.1.min.js, I tried offering a sacrifice to the god of jQuery. None of that
worked. Can you suggest a way to fix this or do I have to keep dismissing multiple javascript error dialog boxes everytime I want to debug my work?
This usually indicates that your scripts are trying to access jQuery (which is $) however, it is probably not yet loaded yet. You will need to wrap all of your scripts that use jQuery with a $(document).ready() block :
$(document).ready(function()
{
//Your code that references jQuery
});
Thanks for the reply, but your explanation doesn't seem to fit. Below is the line of code which is actually throwing the error and it starts off exactly like your suggestion. In other words, I'm already doing that. The error occurs when the layout page
calls @RenderBody()
Do your child pages have any code within them that references any jQuery or Javascript?
(Anything that could be getting called prior to the jQuery being available?)
Yes, that's exactly what is happening. It seems to me that if the jQuery scripts are included in the master/layout page then it should be valid to call jQuery code from the child pages. In fact, that does seem to work in the deployed pages. Where it does
not work is in Visual Studio when I am debugging. There is probably some setting buried deep in Visual Studio among the 5,000 obscure environment settings which will remedy this problem. Sadly the only person that knows where that setting lies is probably
living in a monastery somewhere in Nepal without Internet access.
Just curious if you recently updated jQuery using NuGet?
If so check the file names in your Scripts directory and make sure they correspond with the ones you are calling in your HTML.
NuGet installs the updated files and removes the old ones but does not update links to them in your HTML. This may also explain why it works on the server and not locally being the older jQuery files may still exist on the server.
I believe you that there are settings to disable Javascript debugging in Visual Stuido. I sent out a search party to look for them, but they never returned. I personally reviewed the Tools, Options menu choices but I can't find them.
This is just a guess but if you created an an MVC4 project from a template, there's a good chance it's being bundled with Scripts.Render method. You would have an App_Start folder with a class called BundleConfig.cs.
public class BundleConfig
{
// For more information on Bundling, visit http://go.microsoft.com/fwlink/?LinkId=254725
public static void RegisterBundles(BundleCollection bundles)
{
bundles.Add(new ScriptBundle("~/bundles/jquery").Include(
"~/Scripts/jquery-{version}.js"));
}
}
On the _Layout.cshtml at the end of the document inside of the body there's an optimization method @Scripts.Render("~/bundles/jquery") that loads those scripts at that location. If you're using jquery in the head it will give you undefined errors because
jquery actually won't load until it hits the end of the DOM.
DallasSteve
Member
222 Points
338 Posts
$ is undefined Error
Jan 18, 2013 02:06 PM|LINK
I installed jQuery to be able to use its DatePicker and it works well. But whenever I try to debug my ASP.NET MVC website in Visual Studio I get mutliple "$ is undefined" errors popping up as it tries to run jQuery in the javascript code. I've searched other messages about this error and no one solution seems to stand out.
When I installed jQuery it loaded my script folder with about 2 million .js files. OK, it's not 2 million. It's only about 10. The examples I found said this is what I need to include to get it to run and that's what I have used:
<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/modernizr-1.7.min.js")" type="text/javascript"></script>This is running in a master layout page that is called from _ViewStart.cshtml. Is that part of the problem? I tried taking out the tildes, I tried adding a reference to jquery-1.5.1.min.js, I tried offering a sacrifice to the god of jQuery. None of that worked. Can you suggest a way to fix this or do I have to keep dismissing multiple javascript error dialog boxes everytime I want to debug my work?
www.SteveGaines.us
Rion William...
All-Star
27626 Points
4569 Posts
Re: $ is undefined Error
Jan 18, 2013 02:10 PM|LINK
This usually indicates that your scripts are trying to access jQuery (which is $) however, it is probably not yet loaded yet. You will need to wrap all of your scripts that use jQuery with a $(document).ready() block :
$(document).ready(function() { //Your code that references jQuery });DallasSteve
Member
222 Points
338 Posts
Re: $ is undefined Error
Jan 18, 2013 02:40 PM|LINK
Rion
Thanks for the reply, but your explanation doesn't seem to fit. Below is the line of code which is actually throwing the error and it starts off exactly like your suggestion. In other words, I'm already doing that. The error occurs when the layout page calls @RenderBody()
$(document).ready(function () { $("#QuickReportsLinks").click(function () { ShowLoading(); }); $("#OnlineReferencesLinks").click(function () { ShowLoading(); }); $("#OnlineOrderingLinks").click(function () { ShowLoading(); }); }); <www.SteveGaines.us
Rion William...
All-Star
27626 Points
4569 Posts
Re: $ is undefined Error
Jan 18, 2013 02:51 PM|LINK
Do your child pages have any code within them that references any jQuery or Javascript? (Anything that could be getting called prior to the jQuery being available?)
DallasSteve
Member
222 Points
338 Posts
Re: $ is undefined Error
Jan 18, 2013 03:24 PM|LINK
Yes, that's exactly what is happening. It seems to me that if the jQuery scripts are included in the master/layout page then it should be valid to call jQuery code from the child pages. In fact, that does seem to work in the deployed pages. Where it does not work is in Visual Studio when I am debugging. There is probably some setting buried deep in Visual Studio among the 5,000 obscure environment settings which will remedy this problem. Sadly the only person that knows where that setting lies is probably living in a monastery somewhere in Nepal without Internet access.
www.SteveGaines.us
jprochazka
Contributor
4886 Points
740 Posts
Re: $ is undefined Error
Jan 18, 2013 03:27 PM|LINK
Just curious if you recently updated jQuery using NuGet?
If so check the file names in your Scripts directory and make sure they correspond with the ones you are calling in your HTML.
NuGet installs the updated files and removes the old ones but does not update links to them in your HTML. This may also explain why it works on the server and not locally being the older jQuery files may still exist on the server.
Rion William...
All-Star
27626 Points
4569 Posts
Re: $ is undefined Error
Jan 18, 2013 03:38 PM|LINK
In the Javascript code that you are using within the child pages, are you also encapsulating those calls within $(document).ready()?
There are typically settings to disable Javascript debugging from within your browser if the alerts are too annoying while debugging.
DallasSteve
Member
222 Points
338 Posts
Re: $ is undefined Error
Jan 18, 2013 04:21 PM|LINK
I believe you that there are settings to disable Javascript debugging in Visual Stuido. I sent out a search party to look for them, but they never returned. I personally reviewed the Tools, Options menu choices but I can't find them.
www.SteveGaines.us
jprochazka
Contributor
4886 Points
740 Posts
Re: $ is undefined Error
Jan 18, 2013 04:27 PM|LINK
First try and disable script debuging in IE.
If this is a no go you may try the following:
NOTE: I have not tried this in Visual Studio 2012 nor any Express editions.
To disable JavaScript debuging in Visual Studio 2010 you could do so with a registry edit.
reg add HKLM\SOFTWARE\Microsoft\VisualStudio\10.0\AD7Metrics\Engine\{F200A7E7-DEA5-11D0-B854-00A0244A1DE2} /v ProgramProvider /d {4FF9DEF4-8922-4D02-9379-3FFA64D1D639} /fTo reenable use.
reg add HKLM\SOFTWARE\Microsoft\VisualStudio\10.0\AD7Metrics\Engine\{F200A7E7-DEA5-11D0-B854-00A0244A1DE2} /v ProgramProvider /d {170EC3FC-4E80-40AB-A85A-55900C7C70DE} /fOf course always backup your registry before doing either of the above just to be safe.
medelbrock
Member
647 Points
143 Posts
Re: $ is undefined Error
Jan 18, 2013 09:40 PM|LINK
This is just a guess but if you created an an MVC4 project from a template, there's a good chance it's being bundled with Scripts.Render method. You would have an App_Start folder with a class called BundleConfig.cs.
public class BundleConfig { // For more information on Bundling, visit http://go.microsoft.com/fwlink/?LinkId=254725 public static void RegisterBundles(BundleCollection bundles) { bundles.Add(new ScriptBundle("~/bundles/jquery").Include( "~/Scripts/jquery-{version}.js")); } }On the _Layout.cshtml at the end of the document inside of the body there's an optimization method @Scripts.Render("~/bundles/jquery") that loads those scripts at that location. If you're using jquery in the head it will give you undefined errors because jquery actually won't load until it hits the end of the DOM.