Question

I have a jquery $.post function lik so:

$.post('/test',json_data, function(data) {
                                result=data
});

this function is actually being used in an validation…So it the return value(data) contains true or false. But this value is not being stored in the variable ‘result’. I understand that this is because post makes an asynchronous call and hence it does’nt wait for the response. What I want to ask is, is there some workaround for this? or can this call be made synchronous somehow??

Answer 1

This is considered a bad practice but there is an async parameter in $.ajax() that you can set to false and wait synchronously for a result:

var result;
$.ajax({
  type: 'POST',
  url: '/test',
  data: json_data,
  async: false,
  success: function(data) {
    result=data;
  },
  dataType: 'application/json'
});
//result available here

A more idiomatic, although slightly less convenient in this case, would be to take advantage of callbacks:

function validate(okCallback, errorCallback) {
    $.post('/test',json_data, function(data) {
        if(data) {
            okCallback();
        } else {
          errorCallback();
        }
    });
}

validate(
    function() {
        //proceed
    },
    function() {
        //display validation error
    }
}