Ayende @ Rahien

Hi!
My name is Oren Eini
Founder of Hibernating Rhinos LTD and RavenDB.
You can reach me by phone or email:

ayende@ayende.com

+972 52-548-6969

, @ Q c

Posts: 5,953 | Comments: 44,409

filter by tags archive

JavaScript Race Conditions


About a week ago I posted how to handle Multiple Cascadiong Drop Downs using MS Ajax. That worked, except sometimes it didn't work.

Took me a while to figure out that there was a race  condition there. Let me tell you, Javascript in the browser is not the language for tracking down threading issues. At any rate, here is the fix.

function changeOnParentChangeOnProductsToAvoidRaceConditions()

{

      var behaviors =  Sys.UI.Behavior.getBehaviors($('<%=Benefits.ClientID%>'));

      if(behaviors == null || behaviors.legth==0)

      {

            //wait for the behavior to be defined.

            setTimeout("changeOnParentChangeOnPoliciesToAvoidRaceConditions()", 10);

            return;

      }

      for( var i=0; i<behaviors.length;i++)

      {

            var behavior = behaviors[i];

            //required to get around race condition

            behavior._oldBenefitsOnParentChange = behavior._onParentChange;

            behavior._onParentChange = function()

            {

                  if( $('<%= Insurances.ClientID %>').selectedIndex == 0)

                  {

                        return;

                  }

                  behavior._oldBenefitsOnParentChange ();

            }

      }

}

Event.observe(window, 'load', function() {

      changeOnParentChangeOnProductsToAvoidRaceConditions();

}); 


Comments

Matt

Uh-oh, there's another bug...

line 4:

if(behaviors == null || behaviors.legth==0)

should be:

if(behaviors == null || behaviors.length==0)

length is missing the n.

Keep up the good work, my friend.

Comment preview

Comments have been closed on this topic.

FUTURE POSTS

No future posts left, oh my!

RECENT SERIES

  1. The RavenDB Comic Strip (3):
    28 May 2015 - Part III – High availability & sleeping soundly
  2. Special Offer (2):
    27 May 2015 - 29% discount for all our products
  3. RavenDB Sharding (3):
    22 May 2015 - Adding a new shard to an existing cluster, splitting the shard
  4. Challenge (45):
    28 Apr 2015 - What is the meaning of this change?
  5. Interview question (2):
    30 Mar 2015 - fix the index
View all series

Syndication

Main feed Feed Stats
Comments feed   Comments Feed Stats