Question

我想用英雄联盟API做一些练习编码。为此，您首先需要两条信息：补丁版本（例如＆＃34; 7.12.1＆＃34;）和冠军数据（JSON）。

我遇到的问题是，即使使用我的嵌套承诺，GetData（）也不会等待GetPatch（）解析。

＆＃13;

  var URL = "https://ddragon.leagueoflegends.com/"
  var patch, data

  var GetPatch = new Promise(function(resolve) {
    $.getJSON(URL + "api/versions.json", f = x => {
      patch = x[0]
      console.log("patch version: " + patch)
      resolve()
    })
  })

  var GetData = new Promise(function(resolve) {
    $.getJSON(URL + "cdn/" + patch + "/data/en_US/champion.json", g = x => {
      data = x.data
      console.log(data)
      resolve()
    })
  })

  GetPatch.then(function() {
    GetData.then(function() {
      RunApp()
    })
  })

  function RunApp() {
    console.log("everything is working")
  }

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>

＆＃13;

Answer 1

首先，像$ .AJAX这样的jQuery AJAX函数已经返回了一个promise

其次，您设置承诺的方式是，您立即运行$ .getJSON

您的代码可能类似于 - 请注意缺少var patch, data

var URL = "https://ddragon.leagueoflegends.com/"

var GetPatch = function() {
    return $.getJSON(URL + "api/versions.json").then(x => x[0]);
})

var GetData = function (patch) {
    return $.getJSON(URL + "cdn/" + patch + "/data/en_US/champion.json").then(x => ({patch: patch, data: x.data}));
})

GetPatch()
.then(GetData)
.then(RunApp);

function RunApp({patch, data}) {
    // here you can access patch and data if you need to
    console.log("everything is working")
}

如果您只需data

中的RunApp

return $.getJSON(URL + "cdn/" + patch + "/data/en_US/champion.json").then(x => x.data);
...
function RunApp(data) {
    // here you can access data
    console.log("everything is working")
}

另一种选择 - 可能＆＃34; neater＆＃34;

var URL = "https://ddragon.leagueoflegends.com/"

var GetPatch = function() {
    return $.getJSON(URL + "api/versions.json");
})

var GetData = function (patch) {
    // note the patch[0] below
    return $.getJSON(URL + "cdn/" + patch[0] + "/data/en_US/champion.json");
})

GetPatch()
.then(GetData)
.then(RunApp);

function RunApp(result) {
    // result.data is what x.data was in your code
    console.log("everything is working")
}

嵌套承诺不起作用（jquery + League of Legends API）

1 个答案: