[javascript] Access event to call preventdefault from custom function originating from onclick attribute of tag

I have links like this:

<a href="#" onclick="myfunc({a:1, b:'hi'})" />click</a>
<a href="#" onclick="myfunc({a:3, b:'jo'})" />click</a>

And I would like to do a preventDefault() inside myfunc(), because a # will be added in the address bar when clicking on the link (without doing return false; or href='javascript:void(0);')

Is this possible? Can I get the event inside myfunc()

<script type="text/javascript">
$('a').click(function(){
   return false;
});
<script>

I think when we use onClick we want to do something different than default. So, for all your links with onClick:

$("a[onClick]").on("click", function(e) {
  return e.preventDefault();
});

The simplest solution simply is:

<a href="#" onclick="event.preventDefault(); myfunc({a:1, b:'hi'});" />click</a>

It's actually a good way of doing cache busting for documents with a fallback for no JS enabled browsers (no cache busting if no JS)

<a onclick="
if(event.preventDefault) event.preventDefault(); else event.returnValue = false;
window.location = 'http://www.domain.com/docs/thingy.pdf?cachebuster=' + 
Math.round(new Date().getTime() / 1000);" 
href="http://www.domain.com/docs/thingy.pdf">

If JavaScript is enabled, it opens the PDF with a cache busting query string, if not it just opens the PDF.

e.preventDefault(); from https://developer.mozilla.org/en-US/docs/Web/API/event.preventDefault

Or have return false from your method.

Can you not just remove the href attribute from the a tag?

Try this:

<script>
    $("a").click(function(event) {
        event.preventDefault(); 
    });
</script>

You can access the event from onclick like this:

<button onclick="yourFunc(event);">go</button>

and at your javascript function, my advice is adding that first line statement as:

function yourFunc(e) {
    e = e ? e : event;
}

then use everywhere e as event variable

Simple!

onclick="blabla(); return false"

Without any JS library or jQuery. To open a nice popup window if possible. Fails safely to normal link open.

<a href="https://acme.com/" onclick="onclick="openNewWindow(event, this.href);">...</a>

And the helper function:

function openNewWindow(event, location) {
  if (event.preventDefault && event.stopImmediatePropagation) { 
    event.preventDefault(); 
    event.stopImmediatePropagation(); 
  } else {
    event.returnValue = false; 
  }
  window.open(location, 'targetWindow', 'toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=800,height=450');
}

Add a unique class to the links and a javascript that prevents default on links with this class:

<a href="#" class="prevent-default" 
   onclick="$('.comment .hidden').toggle();">Show comments</a>

<script>
  $(document).ready(function(){

    $("a.prevent-default").click(function(event) {
         event.preventDefault(); 
          });
  });
</script>