Question

I’ve created an AJAX request in a function. However, I am not sure how to return the JSON result – can anyone show me how?

function getData(arg1, arg2, arg3){

    Ext.Ajax.request({
        url: 'getData.php',
        params: {
            arg1: arg1,
            arg2: arg2,
            arg3: arg3
        },
        method: 'POST',
        success: function(response, opts) {
            var jsonData = Ext.util.JSON.decode(response.responseText);
            console.log(jsonData);   <-- Can see the result here!
        },
        failure: function(response, opts) {
            console.log('server-side failure with status code ' + response.status);
        }
    });
    return /jsonData/    <-- Here is the value I want?!

}

Answer 1

The reason your jsonData won’t get any information if you use it in your getData functions is – when the success callback returns (remember, the request is asynchronous) – the getData scope is already exited.

What you can and should do is define a handler function:

function handleSuccess( response, opts )
{
   var jsonData = Ext.util.JSON.decode(response.responseText);
   // use jsonData here in whatever way you please
}

then define your getData like so:

function getData(arg1, arg2, arg3){

    Ext.Ajax.request({
        url: 'getData.php',
        params: {
            arg1: arg1,
            arg2: arg2,
            arg3: arg3
        },
        method: 'POST',
        success: handleSuccess,
        failure: handleError
    });
    // Note the lack of return statement.
}

Of course, you can do the same with your error handling:

function handleError( response, opts )
{
   console.log('server-side failure with status code ' + response.status);
}

Update

there is no way for you to do something like that (where result will get the server response):

...
var result = getData('arg1', 'arg2', 'arg3');
...

reliably and still call an AJAX request. If you think about it – had the above been possible it would essentially become a synchronous request.

The two ways to do your calculations upon jsonData that contains server response are:

1) Do it in handleSuccess function and adjust the rest of your code accordingly (as a side not – you can pass the handler functions as parameters to Ext.Ajax in options.callback and )

2) Make your server request synchronous (not advisable) by usual means