JavaScript synchronization options

Question

I was wondering whenever exists a solution to perform synchronization in JavaScript code. For example I have the following case: I\'m trying to cache some response values from A

Answer 1

I can offer a possible solution, but without seeing the code ... not completely sure what you are doing, but there is no reason why you couldn't do this.

Basic code in jQuery : (not tested and abbreviated ... but I have done things similar)

var needAllThese = {};

$(function(){

      $.ajax("POST","/somepage.aspx",function(data) {
          needAllThese.A = "VALUE";
      });

      $.ajax("POST","/somepage2.aspx",function(data) {
          needAllThese.B = "VALUE";
      });

      $.ajax("POST","/somepage3.aspx",function(data) {
          needAllThese.C = "VALUE";
      });

      startWatching();
});

function startWatching() {
   if (!haveEverythingNeeded()) {
       setTimeout(startWatching,100);
       return;
   }
   everythingIsLoaded();
}

function haveEverythingNeeded() {
    return needAllThese.A && needAllThese.B && needAllThese.C;
}

function everythingIsLoaded() {
   alert("Everything is loaded!");
}

EDIT: (re: your comment)

You're looking for callbacks, the same way jQuery would do it.

   var cache = {};

   function getSomeValue(key, callback) {
       if (cache[key]) callback( cache[key] );

       $.post( "url",  function(data) {
           setSomeValue(key,data);
           callback( cache[key] );
       }); 
   }

   function setSomeValue(key,val) {
        cache[key] = val;
   }

   $(function(){       
        // not sure you would need this, given the code above
        for ( var i = 0; i < some_length; ++i)  {
            $.post( "url", function(data){ 
                setSomeValue("somekey",data); 
            });
        }

        getSomeValue("somekey",function(val){            
             $("#element").txt( val );              
        };            
    });