I definitely like the idea of having an "update" functionality for when the script gets out of date, however I think a better idea is to load the script dynamically on the client-side. I've been toying around with a few ideas over the past few weeks and I think something like this might be a nice solution:

import loadScript from 'load-script';
const GOOGLE_API_URL = 'https://apis.google.com/js/api.js';
/**
 * Load the client library. Return a promise to allow .then() in caller
 */
load = (clientId, discoveryDocs, scope) => {
 return new Promise((resolve, reject) => {
 loadScript(GOOGLE_API_URL, () => {
 window.gapi.load('client:auth2', () => {
 window.gapi.client.init({
 discoveryDocs: discoveryDocs,
 clientId: clientId,
 scope: scope
 }).then(function () {
 resolve();
 });
 });
 });
 });
}

This way, we wouldn't have to release an update to the package every time Google updates the library as you mentioned above and there's a bit less moving parts. You'd use it in your app like this:

import load from 'gapi-client';
load(CLIENT_ID, DISCOVERY_DOCS, SCOPES).then((resp) => {
 // access api via window.gapi
 window.gapi.whatever()
});

which aligns nicely with some of the examples you added in the README.

One thing that would be AWESOME to have in future releases would be a way to specify additional client libraries (such as YouTube) that get loaded in a promise chain, and then resolve the .then() call when all libraries have successfully loaded.

Nice, better idea ! What about this ?

import loadScript from 'load-script'
var gapiLoader = function(){
 return new Promise(resolve => loadScript('https://apis.google.com/js/api.js', resolve))
}

With usages :

gapiLoader()
 .then(() => new Promise(resolve => gapi.load('client:auth2', resolve)))
 .then(() => gapi.client.init({
 discoveryDocs: ['https://www.googleapis.com/discovery/v1/apis/drive/v3/rest'],
 clientId: 'YOUR_CLIENT_ID',
 scope: 'https://www.googleapis.com/auth/drive.metadata.readonly'
 }))
gapiLoader()
 .then(() => new Promise(resolve => gapi.load('client', resolve)))
 .then(() => new Promise(resolve => gapi.client.load('youtube', 'v3', resolve)))
 .then(() => gapi.client.setApiKey('YOUR_API_KEY'))

Would be nice to avoid promisify gapi.load and gapi.client.load too !

@thcolin I love that! Super clean implementation, and then users can specify in their app multiple libraries like client, YouTube, etc. As a quick note, you'll probably need to add load-script as a dependency in package.json.

Do you want to revise this/submit a new pull request (whatever is easier for you) with that implementation in index.js, changes in README.md, some tests, and Travis integration and then I'll approve it? Great work and thanks for the help! 😄

Yes, I will work on it this week, I think about using loadJS over load-script, which is promise based, to avoid to promisify loadScript, if you're okay with it ?

I'm thinking about promisify gapi too, to be consistent, but I'm still wondering how to do it and if the promise should return gapi or if we should keep it global :

// I thinks this solution would be more meaningful, don't you think ?
gapiLoader()
 .then(gapi => gapi.load('client:auth2', () => {}))
// This solution suggest `gapi` is global, it's not very explicit, if we go into this, I think we should properly document it
gapiLoader()
 .then(() => gapi.load('client:auth2', () => {}))

Sorry for late answers, quite busy at the moment !

PS : I will look at google/google-api-nodejs-client too, see if it can help us in any way

Any progress on this? I'm getting 404 errors from client.load("client:auth2", ...) when trying to use gapi-client in my project, but not when I include the Google API script in my page directly. So this library is unfortunately unusable for me until this gets merged or the code gets upgraded.

Great idea to load the script on-the-fly, by the way. And a beautiful promise-y implementation, too. :)

Edit: Also, I'd be happy to help in any way I can with whatever needs doing to get this merged and published.

Hi !

Unfortunately, I didn't found any good solution to handle gapi promisify, so I finally create a gloader.js for my own needs, directly in my project, which look like these :

import loadJS from 'load-js'
const GOOGLE_API_URL = 'https://apis.google.com/js/api.js'
export default typeof gapi !== 'undefined' ? new Promise(gapi) : loadJS([GOOGLE_API_URL])
 // `gapi` is now available
 // WARNING ! App specific needs
 .then(() => new Promise(resolve => gapi.load('client', resolve)))
 .then(() => new Promise(resolve => gapi.client.load('youtube', 'v3', resolve)))
 .then(() => gapi)

The best, like we say earlier, would be to promisify directly in project all gapi methods, if you have any clue on how to do it, I'll be glad to see how ! 🙂