how to detect a function was called with javascript

user_304828 0
Viewed 78476

I have a javascript function.

How to check:

  • if function was called ( in <head></head> section have this function), then not to call the function

  • if function was not called ( in <head></head> section haven't this function), then call the function

like require_once or include_once with PHP

aop javascript
5 Answers

Static variables

Here's how to create static (like in C) variables using self calling functions to store your static variables in a closure.

var myFun = (function() {
  var called = false;
  return function() {
    if (!called) {
      console.log("I've been called");
      called = true;
    }
  }
})()

Abstract the idea

Here's a function that returns a function that only gets called once, this way we don't have to worry about adding boiler plate code to every function.

function makeSingleCallFun(fun) {
  var called = false;
  return function() {
    if (!called) {
      called = true;
      return fun.apply(this, arguments);
    }
  }
}

var myFun = makeSingleCallFun(function() {
  console.log("I've been called");
});

myFun(); // logs I've been called
myFun(); // Does nothing

user_2272990
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