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JavaScript

Posted by Leandro Severino
Leandro Severino
12,674 Points

Is placing event listeners inside a function bad?

Is placing event listeners inside a function bad? This is a sample of my work where I need to have a reference to the previously clicked button

$mapGuideBar.on("click", "li", function(){ mapGuideBarItemClicked(this); }); 

function mapGuideBarItemClicked(item) {

      $mapGuidePopupBtns.eq( btnsEnum.COLLAPSE ).on('click', function(){
           //do something based on value of item
    });

}

1 Answer

Steven Parker
Steven Parker
243,318 Points
Steven Parker
Steven Parker
243,318 Points

It's not bad if it's really what you want to do. So here it seems you only want clicking on the "COLLAPSE" button to work after a click was made on a list item. If that's your intention, this should do it.

But you might also want to guard against attaching redundant handlers in case the same (or another) list item is clicked again.

Leandro Severino
Leandro Severino
12,674 Points

Thank you for you reply Steven Parker . Regarding guarding against attaching redundant handlers, are you referring to something like this?

function someMethod()
{
  $(obj).off('click').on('click', function(e) {
    // put your logic in here 
  });
}
Steven Parker
Steven Parker
243,318 Points
Steven Parker
Steven Parker
243,318 Points

Sure, that should do it. You could also establish both handlers just once, and use a shared variable to control what they do.