Using JS setTimeout in a bookmarklet

Question

I am trying to run some JS code in a bookmarklet in firefox. Here's some basic code to prove the point:

window.setTimeout( function() {alert('i ran');}, 1000 );

when I run code with setTimeout in it, I get the whole page replaced by the counter value that normally gets logged in the console.

Is there a way to catch this output and stop this happening?

Thanks!

Hi, the location part of it looks like this: javascript:window.setTimeout(%20function()%20{alert('i%20ran');},%201000%20); — user1230424, Jul 06 '12 at 11:19

score 5 · Answer 1 · answered Jul 06 '12 at 11:20

5

Try the following:

javascript:(window.setTimeout(function() { alert('i ran'); }, 1000));void(0);

answered Jul 06 '12 at 11:20

epoch

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score 2 · Answer 2 · answered Jul 06 '12 at 11:53

When you use the javascript: protocol in an address bar (which is what all bookmarklets do), the browser does a document.write on whatever the return value is if it's truthy.

A setTimeout call always returns a number for the timer. To fix this you can either append a void(0); like epoch or as I like to do, wrap it in an IIFE:

(function() {
    window.setTimeout( function() {alert('i ran');}, 1000 );
})();

Using JS setTimeout in a bookmarklet

2 Answers2