CODEWITHSUNDEEP
javascript
Snappy
Snappy

Reputation: 203

Javascript alert when function process is complete

Here is Javascript code:

if (selected && this.env.contentframe && !list.multi_selecting)
this.preview_timer = setTimeout(function() {
  ref.msglist_get_preview();
  alert('done');
}, list.dblclick_time);
else if (this.env.contentframe)
  this.show_contentframe(false);

Here is msglist_get_preview() function code:

this.msglist_get_preview = function()
{
    var uid = this.get_single_uid();
    if (uid && this.env.contentframe && !this.drag_active)
      this.show_message(uid, false, true);
  };

And below id the show_message() function:

  this.show_message = function(id, safe, preview)
  {
    if (!id)
      return;

    var win, target = window,
      url = this.params_from_uid(id, {_caps: this.browser_capabilities()});

    if (preview && (win = this.get_frame_window(this.env.contentframe))) {
      target = win;
      url._framed = 1;
    }

url = this.url(preview ? 'preview': 'show', url);
this.location_href(url, target, true);
}:

What I want to alert when a function ref.msglist_get_preview(); process is complete. I have tried but every time alert appears first then function loads.

How can I achieve this ?

Thanks in advance.

Upvotes: 0

Views: 2855

Answers (1)

ankit gupta
ankit gupta

Reputation: 35

setTimeout(function(){...}, 0) simply queues the code to run once the current call stack is finished executing. So the issue you are facing is because your >ref.msglist_get_preview(); is also doing asynchronous task and that's why it gets queued after the setTimeout and hence you get alert('done'); first and then your method execution. Following is the example to explain the same:

this.preview_timer = setTimeout(function() {
abc();
  alert('done');
}, 500);

function abc(){
 setTimeout(function(){
 alert('abc');
 },100) 
} 
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Here alert('abc') will be executed after alert('done')

For your problem you can use the javascript promises. Following code should solve for your problem:

 if (selected && this.env.contentframe && !list.multi_selecting)
this.preview_timer = setTimeout(function() {
  ref.msglist_get_preview().then(function(){
    alert('done');
  })
}, list.dblclick_time);
else if (this.env.contentframe)
  this.show_contentframe(false);

function msglist_get_preview() {
   return new Promise(function(resolve, reject) {
         setTimeout((function() {
            alert('msglist_get_preview worked');
            resolve("Stuff worked!");
        }), 1000);
    });
}

Upvotes: 1

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