Optimal Way to Pass C# Variables to JS

Question

I have several functions that are written in JS that do error checking on my site. On one instance I want to disable two of the checks if a certain instance in the DB is true.

I have something like this on the aspx.cs

if (this.exemptcheck == true) {
  // could set a variable to pass or whatever is optimal here
}

Then in JS I have a function like this in my .aspx

if (NotANumberCheck(item.GetMember("TotalSpace").Value, 'Space must be Numeric') == false) { return false; }

I don't want this check to run if this.examptcheck returns true. What is the optimal way to do this? I have heard of putting variables in non-visible fields but that doesn't seem ideal. Any suggestions would be appreciated.

Thanks

Side-note: It is typically discouraged to check boolean values explicitly for being equal to true or false. A boolean value is already a boolean value. At least in C# and JS, it should not be a problem though. — OregonGhost
– OregonGhost, Commented Jul 10, 2009 at 15:04

Aric TenEyck · Accepted Answer · 2009-07-10 14:58:14Z

2

In the aspx, set a member variable called ExemptCheck. Later, in the JS, do this:

var exemptCheck = <% Response.Write(ExemptCheck.ToString()) %>;

This will give you a JS variable with the same value as the C# variable.

answered Jul 10, 2009 at 14:58

Aric TenEyck

8,0521 gold badge37 silver badges49 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Splashlin Over a year ago

I have this in my aspx.cs private void pageSetup(EventArgs args) { Boolean exemptCheck; if (dss.ExemptCheck == true) { exemptCheck = true; } } I put the following in my JS function onInsert(item) { var exemptCheck = <% Response.Write(exemptCheck.ToString()); %>; } This gives me the following error Compiler Error Message: CS0103: The name 'exemptCheck' does not exist in the current context Is this a scope issue or am i doing something else wrong?

Aric TenEyck Over a year ago

It's a scope issue. exemptCheck needs to be a member variable of the entire page object, not just the pageSetup function; the code between the <% %> is executed during the page render function, long after your pageSetup function has exited.

tanathos · Accepted Answer · 2009-07-10 15:07:38Z

0

Just register your js function only if your condition is true, you don't need to check a variable:

C# code:

if (this.exemptcheck == true) {
    Page.ClientScript.RegisterStartupScript(Page.GetType(), "KEY", "/* code of your JS function that handle the true case */", true);
}

answered Jul 10, 2009 at 15:07

tanathos

5,6164 gold badges36 silver badges49 bronze badges

Comments

casperOne · Accepted Answer · 2009-07-10 14:55:09Z

0

You could write a script section in the page which sets a variable to true/false and then check for that variable in the JS later.

answered Jul 10, 2009 at 14:55

casperOne

74.7k19 gold badges189 silver badges262 bronze badges

Comments

Humberto · Accepted Answer · 2009-07-10 15:00:16Z

0

You may Response.Write() the javascript code only when this.examptcheck is true.

answered Jul 10, 2009 at 15:00

Humberto

7,1994 gold badges33 silver badges46 bronze badges

Comments

Splashlin · Accepted Answer · 2009-07-10 16:04:34Z

0

I ended up using the following command to set the value in the aspx.cs code

Page.ClientScript.RegisterStartupScript(this.GetType(), "", "var stackedUnknownExemptCheck = true;", true);

answered Jul 10, 2009 at 16:04

Splashlin

7,61513 gold badges49 silver badges51 bronze badges

Collectives™ on Stack Overflow

Optimal Way to Pass C# Variables to JS

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related