i have the following in JS:
var rs = new myResponse();
var rq = new myRequest();
c = "function(myRequest,myResponse){myResponse.body = 'hello'; myResponse.end();}";
now, I want to invoke the function that is in 'c'.
Does anyone know how to?
thanks in advance.
By either:
var fn = new Function( "myRequest, myResponse" , "myResponse.body = 'hello';myResponse.end();" );
or by eval function which executes code directly from string:
c = "function(myRequest,myResponse){myResponse.body = 'hello'; myResponse.end();}";
eval("var fn = "+c);
fn();
<script type="text/javascript">
eval("x=10;y=20;document.write(x*y)");
document.write("<br />" + eval("2+2"));
document.write("<br />" + eval(x+17));
</script>
Refer Link:- http://www.w3schools.com/jsref/jsref_eval.asp
//Create the function call from function name and parameter.
var funcCall = strFun + "('" + strParam + "');";
//Call the function
var ret = eval(funcCall);
That's what eval is for.
eval('func = ' + c);
var result = func(rs, rq);
Be careful though as it's not safe for unverified input, ie if it's not from trusted source it can be dangerous.
Why not create a function like in next code:
var rs = new myResponse();
var rq = new myRequest();
c = new Function("myRequest","myResponse","myResponse.body = 'hello'; myResponse.end();");
// or
// c = new Function("myRequest,myResponse","myResponse.body = 'hello'; myResponse.end();");
c();
Or if you cannot, do next for example:
function stringToFunction(str) {
var m=str.match(/\s*function\((.*?)\)\s*{(.*?)}\s*/);
if(m)return new Function(m[1],m[2]);
}
var rs = new myResponse();
var rq = new myRequest();
c = "function(myRequest,myResponse){myResponse.body = 'hello'; myResponse.end();}";
stringToFunction(c)();
// or
//var f=stringToFunction(c);
//f();
Use the eval function, if you really need to do this.
ccome from? Having code in strings is generally a sign of bad design.