Question

I got an if-else script:

     $('#favitem').live('click', function () {
        var fid = $(this).parent().attr('id');

        if (isFav(fid)) {
            alert("Do you want to remove from favorite?");
        }
        else {
            alert("Add to favorite?");
        }
    });

calling the isFav script function:

    function isFav(fid) {

    $.ajax({

        url: '/Stock/IsFav',
        type: 'GET',
        data: { id: fid },
        success: function (result) { return result; }
    });
}

which in turn calling my controller action:

    public Boolean IsFav(int id)
    {
        var food = dbEntities.FOODs.Single(f => f.FoodID == id);
        if (food.FavFlag == 1)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

Everything seems works fine, I get a true from firebug, BUT i get the alert message from the else statement. The if statement just never being entered.
I cant get what is wrong here. Any idea?? Please help..

Answer 1

The ajax request in isFav is async and the isFav method will return before it is completed.

This is probably how I would solve it:

function isFav(fid, callback) {
    $.ajax({
        url: '/Stock/IsFav',
        type: 'GET',
        data: { id: fid },
        success: function (result) { callback(result); }
    });
}


 $('#favitem').live('click', function () {
    var fid = $(this).parent().attr('id');

    isFav(fid,function(result){
        if(result && result.toLowerCase() == "true"){
            alert("Do you want to remove from favorite?"); 
        } else {
            alert("Add to favorite?");  
        }
    });
});

You want to make sure that the code in the if-block is run after the ajax request is done. In this snippet this is solved by the callback method that is called when the ajax success function is executed.