JSFiddle - React, Tailwind, and code Playground

JavaScript

function myFunc(func) {
        //var func = $.parseJSON(obj);
        if (typeof func["before"] === "function") 
            func["before"]();
        // do some stuff
        if (typeof func["after"] === "function") 
            func["after"]();
    }

    var myBefore = function () {
        alert("before");
    }

    var myAfter = function () {
        alert("after");
    }

    myFunc({
        "before": myBefore,
        "after": myAfter
    });