Rather than returning a HtmlService object, you can pass data using jQuery's $.getJSON method and retrieve data from the doGet function with ContentService. Google Apps Script does not accept CORS, so using JSONP is the best way to get data to and from your script. See this post for more.
Working CodePen Example
I split your HTML and scripts for clarity. None of the HTML changed from your original example.
Code.gs
function doGet(e) {
var returnValue;
// Set the callback param. See https://stackoverflow.com/questions/29525860/
var callback = e.parameter.callback;
// Get the file and create it in Drive
try {
var blob = UrlFetchApp.fetch(e.parameters.url).getBlob();
DriveApp.createFile(blob);
// If successful, return okay
// Structure this JSON however you want. Parsing happens on the client side.
returnValue = {status: 'okay'};
} catch(e) {
Logger.log(e);
// If a failure, return error message to the client
returnValue = {status: e.message}
}
// Returning as JSONP allows for crossorigin requests
return ContentService.createTextOutput(callback +'(' + JSON.stringify(returnValue) + ')').setMimeType(ContentService.MimeType.JAVASCRIPT);
}
Client JS
$(function() {
$(".google-upload").click(function() {
var appUrl = "https://script.google.com/macros/s/AKfycbyUvgKdhubzlpYmO3Marv7iFOZwJNJZaZrFTXCksxtl2kqW7vg/exec";
var query = appUrl + "?url=";
var popupUrl = query + $('.google-upload').attr("data-url") + "&callback=?";
console.log(popupUrl)
// Open this to start authentication.
// If already authenticated, the window will close on its own.
var popup = window.open(popupUrl, "_blank", "width=600,height=600,scrollbars=1");
$.getJSON(popupUrl, function(returnValue) {
// Log the value from the script
console.log(returnValue.status);
if(returnValue.status == "okay") {
// Do stuff, like notify the user, close the window
popup.close();
$("#result").html("Document successfully uploaded");
} else {
$("#result").html(returnValue);
}
})
});
});
You can test the error message by passing an empty string in the data-url param. The message is returned in the console as well as the page for the user.
Edit 3.7.18
The above solution has problems with controlling the authorization flow. After researching and speaking with a Drive engineer (see thread here) I've reworked this into a self-hosted example based on the Apps Script API and running the project as an API executable rather than an Apps Script Web App. This will allow you to access the [run](https://developers.google.com/apps-script/api/reference/rest/v1/scripts/run) method outside an Apps Script web app.
Setup
Follow the Google Apps Script API instructions for JavaScript. The Apps Script project should be a standalone (not linked to a document) and published as API executable. You'll need to open the Cloud Console and create OAuth credentials and an API key.
The instructions have you use a Python server on your computer. I use the Node JS server, http-server, but you can also put it live online and test from there. You'll need to whitelist your source in the Cloud Console.
The client
Since this is self hosted, you'll need a plain HTML page which authorizes the user through the OAuth2 API via JavaScript. This is preferrable because it keeps the user signed in, allowing for multiple API calls to your script without reauthorization. The code below works for this application and uses the authorization flow from the Google quickstart guides.
index.html
<body>
<!--Add buttons to initiate auth sequence and sign out-->
<button id="authorize-button" style="display: none;">Authorize</button>
<button id="signout-button" style="display: none;">Sign Out</button>
<button onclick="uploadDoc()" style="margin: 10px;" id="google-upload" data-url="https://calibre-ebook.com/downloads/demos/demo.docx">Upload doc</button>
<pre id="content"></pre>
</body>
index.js
// Client ID and API key from the Developer Console
var CLIENT_ID = 'YOUR_CLIENT_ID';
var API_KEY = 'YOUR_API_KEY';
var SCRIPT_ID = 'YOUR_SCRIPT_ID';
// Array of API discovery doc URLs for APIs used by the quickstart
var DISCOVERY_DOCS = ["https://script.googleapis.com/$discovery/rest?version=v1"];
// Authorization scopes required by the API; multiple scopes can be
// included, separated by spaces.
var SCOPES = 'https://www.googleapis.com/auth/drive https://www.googleapis.com/auth/script.external_request';
var authorizeButton = document.getElementById('authorize-button');
var signoutButton = document.getElementById('signout-button');
var uploadButton = document.getElementById('google-upload');
var docUrl = uploadButton.getAttribute('data-url').value;
// Set the global variable for user authentication
var isAuth = false;
/**
* On load, called to load the auth2 library and API client library.
*/
function handleClientLoad() {
gapi.load('client:auth2', initClient);
}
/**
* Initializes the API client library and sets up sign-in state
* listeners.
*/
function initClient() {
gapi.client.init({
apiKey: API_KEY,
clientId: CLIENT_ID,
discoveryDocs: DISCOVERY_DOCS,
scope: SCOPES
}).then(function () {
// Listen for sign-in state changes.
gapi.auth2.getAuthInstance().isSignedIn.listen(updateSigninStatus);
// Handle the initial sign-in state.
updateSigninStatus(gapi.auth2.getAuthInstance().isSignedIn.get());
authorizeButton.onclick = handleAuthClick;
signoutButton.onclick = handleSignoutClick;
// uploadButton.onclick = uploadDoc;
});
}
/**
* Called when the Upload button is clicked. Reset the
* global variable to `true` and upload the document.
* Thanks to @JackBrown for the logic.
*/
function updateSigninStatus(isSignedIn) {
if (isSignedIn && !isAuth) {
authorizeButton.style.display = 'none';
signoutButton.style.display = 'block';
uploadButton.style.display = 'block'
uploadButton.onclick = uploadDoc;
} else if (isSignedIn && isAuth) {
authorizeButton.style.display = 'none';
signoutButton.style.display = 'block';
uploadButton.style.display = 'block';
uploadDoc();
} else {
authorizeButton.style.display = 'block';
signoutButton.style.display = 'none';
uploadButton.style.display = 'none';
isAuth = false;
}
}
/**
* Sign in the user upon button click.
*/
function handleAuthClick(event) {
gapi.auth2.getAuthInstance().signIn();
isAuth = true; // Update the global variable
}
/**
* Sign out the user upon button click.
*/
function handleSignoutClick(event) {
gapi.auth2.getAuthInstance().signOut();
isAuth = false; // update the global variable
}
/**
* Append a pre element to the body containing the given message
* as its text node. Used to display the results of the API call.
*
* @param {string} message Text to be placed in pre element.
*/
function appendPre(message) {
var pre = document.getElementById('content');
var textContent = document.createTextNode(message + '\n');
pre.appendChild(textContent);
}
/**
* Handle the login if signed out, return a Promise
* to call the upload Docs function after signin.
**/
function uploadDoc() {
console.log("clicked!")
var docUrl = document.getElementById('google-upload').getAttribute('data-url');
gapi.client.script.scripts.run({
'scriptId':SCRIPT_ID,
'function':'uploadDoc',
'parameters': [ docUrl ]
}).then(function(resp) {
var result = resp.result;
if(result.error && result.error.status) {
// Error before the script was Called
appendPre('Error calling API');
appendPre(JSON.parse(result, null, 2));
} else if(result.error) {
// The API executed, but the script returned an error.
// Extract the first (and only) set of error details.
// The values of this object are the script's 'errorMessage' and
// 'errorType', and an array of stack trace elements.
var error = result.error.details[0];
appendPre('Script error message: ' + error.errorMessage);
if (error.scriptStackTraceElements) {
// There may not be a stacktrace if the script didn't start
// executing.
appendPre('Script error stacktrace:');
for (var i = 0; i < error.scriptStackTraceElements.length; i++) {
var trace = error.scriptStackTraceElements[i];
appendPre('\t' + trace.function + ':' + trace.lineNumber);
}
}
} else {
// The structure of the result will depend upon what the Apps
// Script function returns. Here, the function returns an Apps
// Script Object with String keys and values, and so the result
// is treated as a JavaScript object (folderSet).
console.log(resp.result)
var msg = resp.result.response.result;
appendPre(msg);
// do more stuff with the response code
}
})
}
Apps Script
The Apps Script code does not need to be modified much. Instead of returning using ContentService, we can return plain JSON objects to be used by the client.
function uploadDoc(e) {
Logger.log(e);
var returnValue = {};
// Set the callback URL. See https://stackoverflow.com/questions/29525860/
Logger.log("Uploading the document...");
try {
// Get the file and create it in Drive
var blob = UrlFetchApp.fetch(e).getBlob();
DriveApp.createFile(blob);
// If successful, return okay
var msg = "The document was successfully uploaded!";
return msg;
} catch(e) {
Logger.log(e);
// If a failure, return error message to the client
return e.message
}
}
I had a hard time getting CodePen whitelisted, so I have an example hosted securely on my own site using the code above. Feel free to inspect the source and take a look at the live Apps Script project.
Note that the user will need to reauthorize as you add or change scopes in your Apps Script project.
