function jsoncall(){
$.getJSON("http://localhost:3000/data", function (data) {...});
$.getJSON("http://localhost:3000/data", function (data) {...});
}
jsoncall.callback(function(){
//do stuff
});
Something like the pseudocode above. Is there a method in JavaScript that considers async calls like the getJSON above?
Use Deferred : [https://api.jquery.com/jquery.deferred/][1]
function jsoncall(){
var $def = $.Deferred();
$.getJSON("http://localhost:3000/data", function (data) {
$def.resolve(data);
});
return $def;
}
jsoncall.done(function(data){
//do stuff
});
If you're asking what I think you are, then you need to implement the callback in the function.
function jsonCall(callback) {
$.getJSON('http://localhost:3000/data', function(data) {
....
callback(data);
});
}
jsonCall(function(data) {
...
});
Make a utils.js and put your ajax function there call it where ever required.
//utils.js
function doAjax(callbackFunc, method, url) {
var xmlHttpReq = new XMLHttpRequest();
xmlHttpReq.open(method, url);
xmlHttpReq.onreadystatechange = function() {
if (xmlHttpReq.readyState == 4 && xmlHttpReq.status == 200) {
callbackFunc(xmlHttpReq.responseText,buttonArrayInit);
}
}
xmlHttpReq.send(null);
}
function loadMyJson(categoryValue){
if(categoryValue==="veg")
doAjax(print,"GET","http://localhost:3004/vegetables");
else if(categoryValue==="fruits")
doAjax(print,"GET","http://localhost:3004/fruits");
else
console.log("Data not found");
}
function (data) {...}the callback? :)jsoncallis just like$.getJSON- you could simply dojsoncall = $.getJSONsince they are functionally equal. If you need to wait until it's done, then I would recommend looking into$.Deferredor ES6 Promises.function jsoncall(){ return $.getJSON(...) }and thenjsoncall().then(callback)But the deferred-implementation of jQuery is imo. something between not good and awful, depending on the version you're using. I'd reccomend you taking a look at "real" promises.