How to return AJAX response Text? [duplicate]

Question

This question already has an answer here:

• How do I return the response from an asynchronous call? 33 answers

I use prototype to do my AJAX development, and I use the code like this:

somefunction: function(){
    var result = "";
    myAjax = new Ajax.Request(postUrl, {
        method: 'post',
        postBody: postData,
        contentType: 'application/x-www-form-urlencoded',
        onComplete: function(transport){
            if (200 == transport.status) {
                result = transport.responseText;
            }
        }
    });
    return result;
}

And I find that the "result" is an empty string. So, I tried this:

somefunction: function(){
    var result = "";
    myAjax = new Ajax.Request(postUrl, {
        method: 'post',
        postBody: postData,
        contentType: 'application/x-www-form-urlencoded',
        onComplete: function(transport){
            if (200 == transport.status) {
                result = transport.responseText;
                return result;
            }
        }
    });

}

But it didn't work also. How can I get the responseText for other method to use?

Answer 1

remember that onComplete is called long after the someFunction is done working. What you need to do is pass a callback function to the somefunction as a parameter. This function will be called when the process is done working (ie, onComplete):

somefunction: function(callback){
    var result = "";
    myAjax = new Ajax.Request(postUrl, {
        method: 'post',
        postBody: postData,
        contentType: 'application/x-www-form-urlencoded',
        onComplete: function(transport){
            if (200 == transport.status) {
                result = transport.responseText;
                callback(result);
            }
        }
    });

}
somefunction(function(result){
  alert(result);
});

Answer 2

How about adding "asynchronous: false" in your code? In my case, it worked well :)