// A couple of global variable that we will use to test the idea
var sharedGlobal = "I am shared";
var notSharedGlobal = "But I will not be shared";

function submit() {
  // Another two function scoped variables that we will also use to test
  var sharedFuncScope = "I am in function scope and shared";
  var notSharedFuncScope = "I am in function scope but I am not shared";

  // The custom scope object, in here you can choose which variables to share with the custom function
  var funcScope = {
    sharedGlobal: sharedGlobal,
    sharedFuncScope: sharedFuncScope
  };

  // Read the custom function body
  var customFnText = document.getElementById("customfn").value;
  // create a new function object using the Function constructor, and bind it to our custom-made scope object
  var func = new Function(customFnText).bind(funcScope);

  // execute the function, and print the output to the page. 
  document.getElementById("output").innerHTML = JSON.stringify(func());

}

// sample test function body, this will test which of the shared variables   does the custom function has access to. 
/* 
return {
        sharedGlobal : this.sharedGlobal || null,
         sharedFuncScope : this.sharedFuncScope || null,
       notSharedGlobal : this.notSharedGlobal || null,
         notSharedFuncScope : this.notSharedFuncScope || null
 }; 
*/

Add your custom body here



Submit