从 javascript 调用 Google 云打印/搜索 API

Question

有没有人通过 JavaScript 使用 Google 云打印（特别是 /search）API 取得任何成功？

我尝试了多种方法，但不断收到以下错误。

XMLHttpRequest 无法加载 https://www.google.com/cloudprint/search。请求的资源上不存在“Access-Control-Allow-Origin”标头。 Origin 'http://localhost:8080' 因此不允许访问。

代码sn-p：

    var search = new XMLHttpRequest();

    search.open('POST', 'https://www.google.com/cloudprint/search', true);
    search.withCredentials = true;          
    search.setRequestHeader("X-Cloud-Print", "Google-JS");

    search.onreadystatechange = function(response){
            console.log(response);
    };

    search.send();

我可以使用演示表单发布：

    <form action="https://www.google.com/cloudprint/search" method="post" enctype="multipart/form-data" id="submitForm">
      <input type="submit" value="Search"/>
    </form>     

来自完全相同的网页并且成功；我花了很长时间确保这两个请求在提交的数据和标题方面看起来相同，但无济于事。我不愿意用 Java 写这个（因为试图避免涉及服务器后端），并且欢迎任何帮助。

Answer 1

Auth.html：

<a href='<?!= getAuthURL(); ?>' target='_blank'>
<button>Authorize!</button>
</a>

授权。

  function test() {
  var html = HtmlService.createTemplateFromFile("Auth").evaluate().setSandboxMode(HtmlService.SandboxMode.NATIVE).setTitle("Test");
  SpreadsheetApp.getUi().showModalDialog(html, "Test");
}
function getAuthURL() {
  var options= {
    client_id : "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com", // your id
    scope : "https://www.googleapis.com/auth/cloudprint",
    redirect_uri : "https://script.google.com/macros/d/MDYeOxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/usercallback", // your uri
    state : ScriptApp.newStateToken().withMethod("getAuthResponse").createToken()
  };
  var url = "https://accounts.google.com/o/oauth2/auth?response_type=code&access_type=offline";
  for(var i in options) 
    url += "&"+i+"="+encodeURIComponent(options[i]);
  return url;
}

获取 oAuth 令牌并调用 Google 云打印

function getAuthResponse(q) {
  var options = {
    method: "post",
    muteHttpExceptions: true,
    payload: {
      code: q.parameter.code,
      client_id : "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com", // your id 
      client_secret : "xxxxxxxxxxxxxxxxxxxxxxxx", // your secret
      redirect_uri: "https://script.google.com/macros/d/MDYeOxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/usercallback", // your uri
      grant_type: "authorization_code"
    }
  }
  var response = JSON.parse(UrlFetchApp.fetch("https://accounts.google.com/o/oauth2/token", options));
  var auth_string = response.token_type+" "+response.access_token;
  options.method = "get";
  options.payload = null;
  options.headers = {Authorization: auth_string};
  response = UrlFetchApp.fetch("https://www.google.com/cloudprint/search",options);
  return ContentService.createTextOutput(response.getContentText());
}