jQuery类返回undefined [重复]
问题描述：
This question already has an answer here:
I try to create a simple ajax request class in jQuery. The problem I have here is that in the process function I can get the response from variable response . I return response but outside the request it is undefined .. I tried with global variables of some sorts, didn't work out. So now I try to get help from here.
The app.js
var AjaxRequest = Class.extend({
init: function(url) {
this.url = url;
},
process: function() {
var response;
$.get("http://test.dec/ajax.php", function(data) {
var obj = jQuery.parseJSON( data);
response = obj;
console.log(response); // Get correct output
return response;
});
}
});
$('#test').on('click', function() {
var request = new AjaxRequest('ajax.php');
console.log(request.process()); // Get undefined
});
The PHP ajax.php
<?php
$json = json_encode(['test' => 'test123']);
echo $json;
?>
</div>
答
The problem is that ajax requests are asynchronous. What you want to do maybe is pass in a callback to process so when it completes, it will call the function to continue.
Here is an example:
var AjaxRequest = Class.extend({
init: function(url) {
this.url = url;
},
process: function(callback) {
var response;
$.get("http://test.dec/ajax.php", function(data) {
var obj = jQuery.parseJSON( data);
response = obj;
console.log(response); // Get correct output
callback(response);
});
}
});
$('#test').on('click', function() {
var request = new AjaxRequest('ajax.php');
request.process(function(data) { console.log(data); });
});
Please have a read through this on how asynchronus calls work.
答
please Try this:
$.ajax({
url: 'your url',
global: false,
type: 'POST',
data: {},
async: false,
success: function() {}
});