jQuery 如何使ajax同步？
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how to make ajax synchronous?
提问by
How do I make function out of this?
我如何利用这个功能？
//check if station is alive
$.ajax({
url: "lib/grab.php",
data: "check_live=1&stream_url="+valueSelected,
type: "GET",
success: function (resp) {
if (resp == 1) {
play_this(valueSelected);
} else {
//
}
},
error: function (e) {
console.dir(e);
}
});
I thought I could do something like this:
我以为我可以做这样的事情：
function is_alive(valueSelected) {
result = false;
//check if station is alive
$.ajax({
url: "lib/grab.php",
data: "check_live=1&stream_url="+valueSelected,
type: "GET",
success: function (resp) {
if (resp == 1) {
result = true;
} else {
//
}
},
error: function (e) {
console.dir(e);
}
});
return result;
}
But obviously due to asynchronous nature of ajax call, result always returns false.
但显然由于ajax调用的异步性，result总是返回false。
What is the trick of dealing with this situation?
处理这种情况的诀窍是什么？
Seems to work:
似乎工作：
//check if station is alive
function is_alive(url) {
//
var result = false;
//
return $.ajax({
url: "lib/grab.php",
data: "check_live=1&stream_url="+url,
type: "GET",
success: function (resp) {
if (resp == 1) {
//
result = true;
//
}
},
error: function (e) {
console.dir(e);
}
}).then(function() {
return $.Deferred(function(def) {
def.resolveWith({},[result,url]);
}).promise();
});
}
And call it like this:
并这样称呼它：
//Change song on select, works both for fav and station lists
$(document).on("click", ".ui-listview li a", function(){
var valueSelected = $(this).data("station-url");
//
is_alive(valueSelected).done(function(result,url){
if (result) {
//
play_this(valueSelected);
//
}
});
});
采纳答案by Kevin B
You don't have to make it synchronous to make it a useful function.
您不必使其同步即可使其成为有用的功能。
function is_alive(valueSelected) {
//check if station is alive
return $.ajax({
url: "lib/grab.php",
data: "check_live=1&stream_url=" + valueSelected,
type: "GET",
error: function (e) {
console.dir(e);
}
}).then(function (resp) {
return $.Deferred(function(def){
def.resolveWith({},[resp == 1,valueSelected]);
}).promise();
});
}
is_alive(somevalue).done(function(result,valueSelected){
alert(result);
alert(valueSelected);
});
回答by Cillier
You can supply the async: false option
您可以提供 async: false 选项
function is_alive(valueSelected) {
result = false;
//check if station is alive
$.ajax({
async: false,
url: "lib/grab.php",
data: "check_live=1&stream_url="+valueSelected,
type: "GET",
success: function (resp) {
if (resp == 1) {
result = true;
} else {
//
}
},
error: function (e) {
console.dir(e);
}
});
return result;
}
