Is there a way to call function defined inside onload from an external file

Question

Following is a sample code created based on the scenario. showData() function is defined inside a javascript load function. I wanted to call showData() from another file maybe on a button click. I know this will work if the showData is made global. It's not possible to make the function global, as in this scenario it's a dynamically generated code. Is there anyway in JS that allows to call such functions ?

// Not possible to change the structure of this file as its coming dynamically
window.addEventListener("load", function() {
  showData(); // 1st time call
  function showData() {
    console.log('starting execution')
  }
});

// Calling from another file
showData(); // 2nd time call - not possible

who say you cannot make it global? did you try `window.showData = showData` — bill.gates, Nov 23 '20 at 09:08
This might help you https://stackoverflow.com/questions/49616639/how-can-i-export-all-functions-from-a-file-in-js — spyshiv, Nov 23 '20 at 09:27
`dispatchEvent(new Event('load'));` I don't even want to post this as answer. Only if you are **sure** that the load event contains only that function call — Cid, Nov 23 '20 at 15:31

score 1 · Answer 1 · answered Nov 23 '20 at 09:28

1

No.

The function is declared inside another function. Its scope is that function.

Unless you change that code to make it a global, it isn't accessible from outside the containing function at all.

answered Nov 23 '20 at 09:28

Quentin

914,110
126
1,211
1,335

score 1 · Answer 2 · answered Nov 23 '20 at 09:35

If the structure of the code can't be changed, perhaps you could try attaching your function to the global window object, like:

window.addEventListener("load", function() {
  // attached to window
  window.showData = function() {
    console.log('starting execution')
  };

  window.showData(); // 1st time call
    
});

// Calling from another file
window.showData();

But make sure the second call (from the other file) has a little bit of a delay (remember the eventListener has to be attached to the window first, before the function becomes available).

You could try:

// second call
setTimeout(function() {
    window.showData();
}, 1000);

Is there a way to call function defined inside onload from an external file

2 Answers2