I swapped my index.htm to default.aspx which contains some vbscript but for some odd reason it worked as a .htm but as an .aspx page is gives me this error:
BC30289: Statement cannot appear within a method body. End of method assumed.
Is there a quick simple fix for this? or do I have to reprogram my vbscript to work around C# or VB? Any ideas?
Assuming your vbscript is meant to be client-side, the change to .aspx might be running the vbscript as server code instead of client-side code. Try putting the vbscript in a script element:
<script>
' vbscript code...
</script>
If you do want the VB to run on the server instead of the client, make sure you are not declaring another function within the Page_Load() function. You can't declare a function within a function.
It would also be helpful to see your code.
You might want to check that your code is placed properly within your .aspx page.
<script runat="server" language="vb">
</script>
Related
I have a form in my content page for which I am doing some client side validations via Javascript. The Javascript behaves as expected if I place the JS code directly in the content page. But if I place the JS code in it's own file and try accessing that from the content/master page (through the script tag's src attribute), I get a run time error when the validation function in JS being called.
To be specific, I get the below error.
Microsoft JScript runtime error: Objected expected/required at this line - document.getElementById('<%=txtemailId.ClientID %>').value
txtemailId is in the content page.
Javascript code is placed in validation.js and accessed via master page.
The reason I guess is that when .net is parsing the files, it is unable to substitute txtemailId.ClientID with the client side value that would be generated later on. So, how should one go about it? Thanks!
The answer to this is quite simple.
Within your content page declare an in-line JScript variable, make sure this is above your tag.
<script>
var emailClientId = <%=txtemailId.ClientID%>;
</script>
Within your include.js file make use of the globally scoped emailClientId variable.
Obviously this is a bit clumsy because not all of the JScript code is contained within the include.js file, which makes it difficult to debug / diagnose as it is not clear specifically where the value is coming from. You should clearly comment / document this within your code to make maintenance of he codebase easier in the future.
You're right, the code <%=txtemailId.ClientID %> will only get replaced with the real client ID by ASP.Net if this code is in an ASP.Net file. So if you put this javascript in a separate .js file, ASP.Net will know nothing about it, and the code will not be parsed.
The easiest way to achieve this is to make the control IDs parameters of your functions. This way you can have the calling javascript code in your .aspx (or .ascx) file, along with the <%=txtemailId.ClientID %> code.
Standalone .js files are not run through the ASPX parser, so your expression is not being evaluated.
To solve the problem, you could set global variables (or function parameters, or something else) in the ASPX files with the IDs of the controls, then use them in the standalone .js file.
Alternatively, you could uses class names (which don't get mangled) instead of IDs. (This is very simple using jQuery)
An approach like this is best suited for something you want to achieve:
validation.js
var Validation = {
EmailId: null,
Validate: function() {
var email = document.getElementById(EmailId).value;
}
}
page.aspx
Validation.EmailId = '<%=txtemailId.ClientID %>'; //initialize
Validation.Validate(); //whenever you want to validate
I ran into an annoying problem: the following code gives a warning in Visual Studio.
<script type="text/javascript">
var x = <%: ViewData["param"] %>;
</script>
The warning is "Expected expression". Visual Studio gets confused, and all the javascript code after that is giving tons of warnings. Granted, it's all warnings, and it works perfectly fine in runtime - but it is very easy to miss real warnings among dozen of false positives.
It was working the same way in VS2008, and it wasn't fixed in VS2010. Does anybody know if there is a workaround, or a patch?
You need to wrap the server side expression in quotes.
<script type="text/javascript">
var x = "<%: ViewData["param"] %>";
</script>
This is what I got from Microsoft:
Unfortunately, this is due to a design limitation of our editor. We have had multiple users provide the same feedback, but we do not have a good solution at this time, other than to avoid server-side generation of client script. We will consider this issue in our planning for the next Visual Studio release.
You can trick the IDE using quotes or line comments
original code:
<script type="Text/javascript">
<%If Page.IsPostback Then%>
alert("my javascript code");
<%End If%>
</script>
solution:
<script type="Text/javascript">
//<%If Page.IsPostback Then%>
alert("my javascript code");
//<%End If%>
</script>
The approach you're taking is not a particularly sturdy one. Obviously it wouldn't work if you wanted to move your Javascript code to a separate file in order to improve your page load times....
You're better off using hidden form fields to move data from the server to client script. Alternatively, you can build the variable setter JS code programmatically by doing a bunch of string concatenation, then using the ClientScriptManager.RegisterClientScriptBlock() method to inject it into the output.
I believe that you ask from visual studio to understand too difficult thinks.
How visual studio can know what is inside the string that you pass ?, its parameters, its more code, what it is ???.... How VS can know what it is so can tread them that way ?
So they decide that everything on script tag there must be JavaScript.
My opinion is that if you won to avoid this error, Write render this JavaScript on code behind and not inside aspx page.
string cPlaceMeOnScript = "<script type=\"text/javascript\">var x =" + ViewData["param"] +";</script>"
and use any method to place this string on the start of your script.
I can't believe how many responses say "Put the JavaScript in the code-behind instead". This is a very bad idea, and muddles your code by mixing presentation with business logic. As the original poster stated, this is only a mere warning. While annoying, it's not worth mixing your presenatational behavior in with your server-side code (a.k.a. writing poor code) over.
This is not the standard behavior, and it is just happening randomly, and in such a situation just renaming the file and then building will help, (and it is possible that even without building it will be solved), and you can then revert back.
You can also completely disable warnings on Java Script under Tools -> Options -> Text Editor -> JScript -> Miscellaneous.
Of course in this case you will miss the Java Script warnings, but at least you will be able to concentrate on the server side warnings.
I know that you can create 'server-side comments' (they won't be sent as comments/text to the client) in ASP.NET (MVC) via the <%-- Comment --%> tags.
However, I can't seem to do this inside of a <script> tag -- if I try this I get a bunch of code underlined in red, and weird unrelated errors ("Invalid expression term '}') etc. from Visual Studio.
Is there another way to have server-side comments inside of the script tag? I want to comment my inline Javascript, but don't want my comments sent to the client.
You can add the comment no problem.
Visual Studio is stupid and doesn't recognize the ASP <%-- Comment %> tags in JS. Your page will still compile fine.
As mentioned in another answer, using //<%-- Comment %> will hide your comments (but leave the //).
Also, be careful of ASP.NET's habit of ignoring whitespace or line breaks around ASP-wrapped code:
//<%-- Comment %>
var whatever = '';
May become:
//var whatever = '';
at run time.
Have you tried commenting the lines with javascript comments as well? Apparently this should work:
<script type="text/javascript">
<%--
// Comments that
// will not be rendered
//--%>
</script>
Taken from a post on Scott Guthrie's blog here.
You can add comments in javascript by making each line start with "//". Those survive through the ASP.NET engine just fine.
Server tags does work inside aspx javascript tags.
But visualstudio doesn't get it, it gives you lots of errors, but if you run the page it will work.
Its the same if you do serverside inside a html tag.
Shouldn't you ideally be decoupling your JS code from ASPX as much as possible? The bulk of your JS code that is complicated enough to deserve commenting should reside in stand-alone JS files. You should have the bare minimum amount of code on the ASPX side and simply invoke JS functions etc. from the external JS files.
I have created custom control using asp.net 2.0. The control contains a textbox txtDate. I have also created a javascript file DateMask.js which contains a function maskDate(). I have attached the maskDate() with textbox using -
txtDate.Attributes.Add("onkeypress","maskDate()");
I have also registered the script using ClientScript.RegisterStartupScript.
When I execute the aspx page containing my custom control it is generating script error showing that maskDate() is undefined.
Could anybody tell me what exactly the problem is?
Thanks for your cooperation.
One way to do it would be to place a literal control above your textbox, and assign the script to it in the code behind:
literal1.Text = "<script>function maskDate() {...}</script>";
The benefit to this, is you would not need to have to reference the script file with some tricky relative paths depending on where your usercontrol is used.
Make sure you didn't forget <form runat="server" ID="Form1"></form> at the end of the <head> tag!
As you can read in Using JavaScript Along with ASP.NET 2.0 under "The Difference Between Page.ClientScript.RegisterStartupScript and Page.ClientScript.RegisterClientScriptBlock" they rely on the location of the form tag.
We have shown two different methods
for placing JavaScript functions on an
ASP.NET page—so what is the
difference? The main difference is
that the RegisterStartupScript method
places the JavaScript at the bottom of
the ASP.NET page right before the
closing element. The
RegisterClientScriptBlock method
places the JavaScript directly after
the opening element in the
page. So what difference does this
make? It can make quite a bit of
difference, as we will see.
I'm trying to implement this specific example using asp.net page instead of asp page.
If you look at the example you can see that there are 2 parts for the page:
Mail asp page. This page have JS code that calls other asp file for AJAX use.
the other asp page which holds the JS code.
The responseText of the call is the client side code, so, when I write something like this:
<html><head><title>test</title><script language="javascript" runat="server"
type="text/javascript">function test(){Response.Write("This is a Test!");
</script><body onload="test()"></body></html>
the page ignores my server side code and returns this:
<html><head><title>test</title><body onload="test()"></body></html>
what should I need to do to make him process my JS code and return its output?
Thanks in advance,
Oz Radiano.
asp.net does not process javascript server side, so setting the script tag runat=server with language="javascript" will be mostly ignored.
I think if you change it to "JScript" it will work, however, this has nothing to do with ajax.
"runat = server" says, preprocess this on the server and don't send it to the client.
If the language is a processable one it will be evaluated as well.
Try implementing the example after watching some videos from http://www.asp.net/learn/ajax-videos/ and http://www.asp.net/learn/ajax/
Its very easy to implement AJAX in asp.net then ASP. I can clearly give you the correct source code. :) But you seem to try out new things. Let us know how it goes!
Thanks for your responses, they made me understand that I'm not sure what my problem is.
After failing in implementing this exact example, I've googleed "how to run asp code using ajax"
this result returned and made it very clear.
Thanks again.