JavaScript functions in second parameter of addEventListener are ran during parsing,before listener is called

👁 Image	Vladimir Ermakov Reporter
	Description • 24 years ago

If the second parameter of addEventListener() is an actual function call, this function is called during the parsing of the script, not when the event occurs. Basicly if you have document.addEventListener("load",test(),0) in the HEAD The function test is going to be executed before the BODY is even displayed. The correct behaviour would be to generate some sort of a javascript error. this occurs on 2002-01-07-03-trunk build on windows 98

👁 Image	Vladimir Ermakov Reporter
	Comment 1 • 24 years ago

The testcase script looks like this: function test(e) { alert("This should never be displayed because the function is never called"); } document.addEventLister("neveroccurringevent",test(),0); This event never occurs, even though the function test() is executed

👁 Image	Johnny Stenback (:jst)
	Comment 2 • 24 years ago

This bug is invalid. If you want to add the function |test| as an event listener, do: document.addEventLister("neveroccurringevent", test, 0); that will do just that, if you do what your testcase does: document.addEventLister("neveroccurringevent", test(), 0); mozilla will try to add the return value of calling the function test() as the event listener, not the function test itself. Big difference. Mozilla does exactly what you're asking it to do here, there is no bug shown by this testcase. Marking INVALID.

👁 Image	Vladimir Ermakov Reporter
	Comment 3 • 24 years ago

ok