I am implementing a callback for a 3rdParty javascript library and I need to return the value, but I need to get the value from the server. I need to do something like this:
3rdPartyObject.getCustomValue = function {
return $.getJSON('myUrl');
}
getJson uses XMLHttpRequest which (I believe) has both synchronous and asynchronous behaviors, can I use the synchronouse behavior?
看看jQuery的源代码，这就是$.getJSON个功能:
getJSON: function( url, data, callback ) {
return jQuery.get(url, data, callback, "json");
},
这就是$.get所做的一切:
get: function( url, data, callback, type ) {
// shift arguments if data argument was omitted
if ( jQuery.isFunction( data ) ) {
callback = data;
data = null;
}
return jQuery.ajax({
type: "GET",
url: url,
data: data,
success: callback,
dataType: type
});
},
No black magic there. Since you need to customize stuff other than the basic $.getJSON functionality, you can just use the low-level $.ajax function and pass the async option as false:
$.ajax({
type: 'GET',
url: 'whatever',
dataType: 'json',
success: function() { },
data: {},
async: false
});