通过TVJS-tvOS消费JSon接口调用

Question

我正在尝试使用tvOS，我有一个关于处理json调用的小问题。我必须通过API获取一些数据，假设为了测试起见，我调用此链接

http://query.yahooapis.com/v1/public/yql?q=select%20item%20from%20weather.forecast%20where%20location%3D%223015%22&format=json

我试着通过一些修改来使用这个函数

function getDocument(url) {
  var templateXHR = new XMLHttpRequest();
  templateXHR.responseType = "json";
  templateXHR.open("GET", url, true);
  templateXHR.send();
  return templateXHR;
}

但没成功。有什么提示或帮助吗？

如果我需要使用NodeJS，我该怎么做？

Answer 1

这是我开始工作的一个。它在许多方面都不理想，但它向您展示了一些可以开始使用的东西。

function jsonRequest(options) {

  var url = options.url;
  var method = options.method || 'GET';
  var headers = options.headers || {} ;
  var body = options.body || '';
  var callback = options.callback || function(err, data) {
    console.error("options.callback was missing for this request");
  };

  if (!url) {
    throw 'loadURL requires a url argument';
  }

  var xhr = new XMLHttpRequest();
  xhr.responseType = 'json';
  xhr.onreadystatechange = function() {
    try {
      if (xhr.readyState === 4) {
        if (xhr.status === 200) {
          callback(null, JSON.parse(xhr.responseText));
        } else {
          callback(new Error("Error [" + xhr.status + "] making http request: " + url));
        }
      }
    } catch (err) {
      console.error('Aborting request ' + url + '. Error: ' + err);
      xhr.abort();
      callback(new Error("Error making request to: " + url + " error: " + err));
    }
  };

  xhr.open(method, url, true);

  Object.keys(headers).forEach(function(key) {
    xhr.setRequestHeader(key, headers[key]);
  });

  xhr.send();

  return xhr;
}

您可以使用以下示例来调用它：

jsonRequest({
  url: 'https://api.github.com/users/staxmanade/repos',
  callback: function(err, data) {
    console.log(JSON.stringify(data[0], null, ' '));
  }
});

希望这能有所帮助。

Answer 2

我在tvOS上测试了这一点--使用jQuery的语法非常有效(基本测试通过)：

var $ = {};
$.ajax = function(options) {

  var url = options.url;
  var type = options.type || 'GET';
  var headers = options.headers || {} ;
  var body = options.data || null;
  var timeout = options.timeout || null;
  var success = options.success || function(err, data) {
    console.log("options.success was missing for this request");
  };
  var contentType = options.contentType || 'application/json';
  var error = options.error || function(err, data) {
    console.log("options.error was missing for this request");
  };

  if (!url) {
    throw 'loadURL requires a url argument';
  }

  var xhr = new XMLHttpRequest();
  xhr.responseType = 'json';
  xhr.timeout = timeout;
  xhr.onreadystatechange = function() {
    try {
      if (xhr.readyState === 4) {
        if (xhr.status === 200) {
            if (xhr.responseType === 'json') {
                success(null, xhr.response);
            } else {
                success(null, JSON.parse(xhr.responseText));
            }
        } else {
          success(new Error("Error [" + xhr.status + "] making http request: " + url));
        }
      }
    } catch (err) {
      console.error('Aborting request ' + url + '. Error: ' + err);
      xhr.abort();
      error(new Error("Error making request to: " + url + " error: " + err));
    }
  };

  xhr.open(type, url, true);

  xhr.setRequestHeader("Content-Type", contentType);
  xhr.setRequestHeader("Accept", 'application/json, text/javascript, */*');

  Object.keys(headers).forEach(function(key) {
    xhr.setRequestHeader(key, headers[key]);
  });

  if(!body) {
    xhr.send();
    } else {
        xhr.send(body);
    }

  return xhr;
}

在Apple TV上工作的示例查询：

var testPut = function(){

    $.ajax({
        type: 'PUT',
        url: url,
        success: successFunc,
        error: errFunc,
        dataType: 'json',
        contentType: 'application/json',
        data: data2
    });
}
var testGet = function(){
    $.ajax({
        dataType: 'json',
        url: url,
        success: successFunc,
        error: errFunc,
        timeout: 2000
    });

}

var getLarge = function(){
    $.ajax({
        dataType: 'json',
        url: url,
        success: successFunc,
        error: errFunc,
        timeout: 2000
    });
}

Answer 3

您是否在“App.onLaunch”中调用了您的函数

App.onLaunch = function(options) {
  var url = 'http://query.yahooapis.com/v1/public/yql?q=select%20item%20from%20weather.forecast%20where%20location%3D%223015%22&format=json';
  var doc = getDocument(url);
  console.log(doc);
}

可能值得一看https://mathiasbynens.be/notes/xhr-responsetype-json