将函数作为变量存储在localStorage中

Question

I'm trying to store functions in localStorage

class Data extends Component {
    constructor(props);
    var func = {
         f1 : this.f1.bind(this),
         f2 : this.f1.bind(this)
     }
    localStorage.setItem("method",func);

     f1(var id){
      console.log("F1" : id);
     }
     f2(var id){
      console.log("F2" : id);
     }
 }

 class App extends Component{
  constructor(props){
       super(props);
       var m = localStorage.getItem("method");
       m.f1(1);
       m.f2(3);

  }

I get error "m.f1" is not a function. Is it possible to fix that, or is what i'm trying to do impossible ? I want to do it to separate function and component for clarity (to avoid having too long code, and because i use the same function in different components), but it's not necessary

Answer 1

What you can do is to store the function definition as a string in localStorage and then evaluate it using the eval method but it does not mean that you are storing the actual function, you are just storing a string and later you are running it as JavaScript code using eval .

eg

var c = console;

localStorage.setItem("itm", "(function(){ return c})()");

eval(localStorage.getItem("itm")).log("Hello!");

In the above example the c object must be accessible from where you run eval else it will not work because its just a string.