in my project I use some cloud functions: one of them sets custom claims, it works properly, I have a second function that when fired should write some data on the realtime Db,but once is fired I get a CORS Error; this is the faulty function:
exports.insertUser = functions.https.onCall((data)=>{
const db = admin.database();
const reference = "userProfile";
return db.ref(reference).push(data.user).then(()=>{
return {message: "utente inserito"};
}).catch((error)=>{
return error;
})
});
this is the error that I get:
Access to fetch at 'https://us-central1-trasportostudenti-
bc19c.cloudfunctions.net/insertUser' from origin 'http://localhost:8100' has been blocked by CORS policy: Response to preflight request doesn't pass access control check
firebase's log states that the problem is in my code; any suggestions to fix this error?
I'm integrating a CRM with Facebook lead Ads using Zapier, and I can create a lead in Facebook and create it in the CRM without any issues.
After a successful post (i.e. successfully creating the lead), I'm curious what I should be returning, I would have thought
return Ok();
would have been enough. Instead, I get an error message saying:
- Got a non-object result, expected an object from create ()
What happened (You are seeing this because you are an admin):
Executing creates.ZapLead.operation.perform with bundle
Invalid API Response:
- Got a non-object result, expected an object from create ()
What should I be returning?
Code which makes the post is:
perform: (z, bundle) => {
const promise = z.request({
url: 'https://{{bundle.authData.subdomain}}.ngrok.io/api/zapier/create/lead/' + bundle.inputData.lead_type + '/' + bundle.inputData.core_customerTypeId,
method: 'POST',
body: JSON.stringify({
fields: bundle.inputData
}),
headers: {
'content-type': 'application/json'
}
});
// return promise.then((response) => JSON.parse(response.content));
return promise.then((response) => {
if (response.status != 200) {
throw new Error(`Unexpected status code ${response.status}`);
}
});
Any ideas?
Thanks,
David here, from the Zapier Platform team.
While your answer is technically correct, I wanted to add some context about the error and why your solution works.
Zapier expects a javascript object (basically anything valid and wrapped in {}) to come out of a create function. That's why JSON.parse(response.content) works, it's returning whatever the server said. Your code throws an error if it's not a 200, but doesn't return anything if it is a 200. Since undefined is not of type Object, the error you're seeing is thrown.
While {"Success":"Success","Attempt":null,"Id":null,"RequestId":null} is totally a valid response (it's an object!), it's more useful for the end-user to return data about the new lead that was created. That way, it can be used downstream for other actions.
Let me know if you've got any other questions!
As a side note, we're very open to how to make that error message more clear; it's one devs struggle with a lot.
I think I found it. Looks like I need to return this if successful:
{"Success":"Success","Attempt":null,"Id":null,"RequestId":null}
I was trying to use the planner endpoint on version 1 of the graph. The main goal for me is to update the status of a task and decide whether it is ‘completed’ or ‘to do’. The first thing I do is to get all tasks from myself. See the endpoint below:
https://graph.microsoft.com/v1.0/me/planner/tasks
function plannerCompleteTask(id, etag) {
var specialEtag = etag.replace(/\\/g, "");
var deferred = $q.defer();
var endpoint = config.baseGraphApiUrl + 'planner/tasks/' + id;
var data = {
"percentComplete": "100"
};
var configRest = {
headers: {
"content-type": "application/json",
"If-Match": specialEtag
}
}
//"completedDateTime": "2018-02-15T07:56:25.7951905Z",
$http.patch(endpoint, data, configRest).then(function (result) {
console.log('log code', result);
deferred.resolve(result.status);
});
return deferred.promise;
}
I will create the following request
This will return a status: 204 with no content.
If I rerun the query with a "percentageCompleted: 0" in the body I get the following error.
Also If I try to log the request I get back from the AJAX call it doesn't give me back anything. As if there is no error handling being send back. I would need this because I have to reload the data in my application; but right now my code runs before the changes on the graph get completed, yet it returns a 204 status.
So I am clueless to find out when the call doesn't work or to find out when it is finished. Did anyone faced this issue before?
Thanks for reading and any help would be much appreciated. Cheers!
I think what you are looking for is the "prefer" header. If in your patch request you provide the "prefer" header with value "return=representation", the result of the patch will be final task data, including the new etag, with 200 status code, instead of default behavior of returning 204 "no content" status code.
Write operations in Planer are asynchronous. So, when possible, you should always update your local data based on the results of write operations with the prefer header, instead of reading them again.
In your requests, since you are reading the data before the task update is complete, essentially you are updating the same state of the task to be completed and not completed at the same time, which is the reason for the conflict.
I am new to Service Workers, and have had a look through the various bits of documentation (Google, Mozilla, serviceworke.rs, Github, StackOverflow questions). The most helpful is the ServiceWorkers cookbook.
Most of the documentation seems to point to caching entire pages so that the app works completely offline, or redirecting the user to an offline page until the browser can redirect to the internet.
What I want to do, however, is store my form data locally so my web app can upload it to the server when the user's connection is restored. Which "recipe" should I use? I think it is Request Deferrer. Do I need anything else to ensure that Request Deferrer will work (apart from the service worker detector script in my web page)? Any hints and tips much appreciated.
Console errors
The Request Deferrer recipe and code doesn't seem to work on its own as it doesn't include file caching. I have added some caching for the service worker library files, but I am still getting this error when I submit the form while offline:
Console: {"lineNumber":0,"message":
"The FetchEvent for [the form URL] resulted in a network error response:
the promise was rejected.","message_level":2,"sourceIdentifier":1,"sourceURL":""}
My Service Worker
/* eslint-env es6 */
/* eslint no-unused-vars: 0 */
/* global importScripts, ServiceWorkerWare, localforage */
importScripts('/js/lib/ServiceWorkerWare.js');
importScripts('/js/lib/localforage.js');
//Determine the root for the routes. I.e, if the Service Worker URL is http://example.com/path/to/sw.js, then the root is http://example.com/path/to/
var root = (function() {
var tokens = (self.location + '').split('/');
tokens[tokens.length - 1] = '';
return tokens.join('/');
})();
//By using Mozilla’s ServiceWorkerWare we can quickly setup some routes for a virtual server. It is convenient you review the virtual server recipe before seeing this.
var worker = new ServiceWorkerWare();
//So here is the idea. We will check if we are online or not. In case we are not online, enqueue the request and provide a fake response.
//Else, flush the queue and let the new request to reach the network.
//This function factory does exactly that.
function tryOrFallback(fakeResponse) {
//Return a handler that…
return function(req, res) {
//If offline, enqueue and answer with the fake response.
if (!navigator.onLine) {
console.log('No network availability, enqueuing');
return enqueue(req).then(function() {
//As the fake response will be reused but Response objects are one use only, we need to clone it each time we use it.
return fakeResponse.clone();
});
}
//If online, flush the queue and answer from network.
console.log('Network available! Flushing queue.');
return flushQueue().then(function() {
return fetch(req);
});
};
}
//A fake response with a joke for when there is no connection. A real implementation could have cached the last collection of updates and keep a local model. For simplicity, not implemented here.
worker.get(root + 'api/updates?*', tryOrFallback(new Response(
JSON.stringify([{
text: 'You are offline.',
author: 'Oxford Brookes University',
id: 1,
isSticky: true
}]),
{ headers: { 'Content-Type': 'application/json' } }
)));
//For deletion, let’s simulate that all went OK. Notice we are omitting the body of the response. Trying to add a body with a 204, deleted, as status throws an error.
worker.delete(root + 'api/updates/:id?*', tryOrFallback(new Response({
status: 204
})));
//Creation is another story. We can not reach the server so we can not get the id for the new updates.
//No problem, just say we accept the creation and we will process it later, as soon as we recover connectivity.
worker.post(root + 'api/updates?*', tryOrFallback(new Response(null, {
status: 202
})));
//Start the service worker.
worker.init();
//By using Mozilla’s localforage db wrapper, we can count on a fast setup for a versatile key-value database. We use it to store queue of deferred requests.
//Enqueue consists of adding a request to the list. Due to the limitations of IndexedDB, Request and Response objects can not be saved so we need an alternative representations.
//This is why we call to serialize().`
function enqueue(request) {
return serialize(request).then(function(serialized) {
localforage.getItem('queue').then(function(queue) {
/* eslint no-param-reassign: 0 */
queue = queue || [];
queue.push(serialized);
return localforage.setItem('queue', queue).then(function() {
console.log(serialized.method, serialized.url, 'enqueued!');
});
});
});
}
//Flush is a little more complicated. It consists of getting the elements of the queue in order and sending each one, keeping track of not yet sent request.
//Before sending a request we need to recreate it from the alternative representation stored in IndexedDB.
function flushQueue() {
//Get the queue
return localforage.getItem('queue').then(function(queue) {
/* eslint no-param-reassign: 0 */
queue = queue || [];
//If empty, nothing to do!
if (!queue.length) {
return Promise.resolve();
}
//Else, send the requests in order…
console.log('Sending ', queue.length, ' requests...');
return sendInOrder(queue).then(function() {
//Requires error handling. Actually, this is assuming all the requests in queue are a success when reaching the Network.
// So it should empty the queue step by step, only popping from the queue if the request completes with success.
return localforage.setItem('queue', []);
});
});
}
//Send the requests inside the queue in order. Waiting for the current before sending the next one.
function sendInOrder(requests) {
//The reduce() chains one promise per serialized request, not allowing to progress to the next one until completing the current.
var sending = requests.reduce(function(prevPromise, serialized) {
console.log('Sending', serialized.method, serialized.url);
return prevPromise.then(function() {
return deserialize(serialized).then(function(request) {
return fetch(request);
});
});
}, Promise.resolve());
return sending;
}
//Serialize is a little bit convolved due to headers is not a simple object.
function serialize(request) {
var headers = {};
//for(... of ...) is ES6 notation but current browsers supporting SW, support this notation as well and this is the only way of retrieving all the headers.
for (var entry of request.headers.entries()) {
headers[entry[0]] = entry[1];
}
var serialized = {
url: request.url,
headers: headers,
method: request.method,
mode: request.mode,
credentials: request.credentials,
cache: request.cache,
redirect: request.redirect,
referrer: request.referrer
};
//Only if method is not GET or HEAD is the request allowed to have body.
if (request.method !== 'GET' && request.method !== 'HEAD') {
return request.clone().text().then(function(body) {
serialized.body = body;
return Promise.resolve(serialized);
});
}
return Promise.resolve(serialized);
}
//Compared, deserialize is pretty simple.
function deserialize(data) {
return Promise.resolve(new Request(data.url, data));
}
var CACHE = 'cache-only';
// On install, cache some resources.
self.addEventListener('install', function(evt) {
console.log('The service worker is being installed.');
// Ask the service worker to keep installing until the returning promise
// resolves.
evt.waitUntil(precache());
});
// On fetch, use cache only strategy.
self.addEventListener('fetch', function(evt) {
console.log('The service worker is serving the asset.');
evt.respondWith(fromCache(evt.request));
});
// Open a cache and use `addAll()` with an array of assets to add all of them
// to the cache. Return a promise resolving when all the assets are added.
function precache() {
return caches.open(CACHE).then(function (cache) {
return cache.addAll([
'/js/lib/ServiceWorkerWare.js',
'/js/lib/localforage.js',
'/js/settings.js'
]);
});
}
// Open the cache where the assets were stored and search for the requested
// resource. Notice that in case of no matching, the promise still resolves
// but it does with `undefined` as value.
function fromCache(request) {
return caches.open(CACHE).then(function (cache) {
return cache.match(request).then(function (matching) {
return matching || Promise.reject('no-match');
});
});
}
Here is the error message I am getting in Chrome when I go offline:
(A similar error occurred in Firefox - it falls over at line 409 of ServiceWorkerWare.js)
ServiceWorkerWare.prototype.executeMiddleware = function (middleware,
request) {
var response = this.runMiddleware(middleware, 0, request, null);
response.catch(function (error) { console.error(error); });
return response;
};
this is a little more advanced that a beginner level. But you will need to detect when you are offline or in a Li-Fi state. Instead of POSTing data to an API or end point you need to queue that data to be synched when you are back on line.
This is what the Background Sync API should help with. However, it is not supported across the board just yet. Plus Safari.........
So maybe a good strategy is to persist your data in IndexedDB and when you can connect (background sync fires an event for this) you would then POST the data. It gets a little more complex for browsers that don't support service workers (Safari) or don't yet have Background Sync (that will level out very soon).
As always design your code to be a progressive enhancement, which can be tricky, but worth it in the end.
Service Workers tend to cache the static HTML, CSS, JavaScript, and image files.
I need to use PouchDB and sync it with CouchDB
Why CouchDB?
CouchDB is a NoSQL database consisting of a number of Documents
created with JSON.
It has versioning (each document has a _rev
property with the last modified date)
It can be synchronised with
PouchDB, a local JavaScript application that stores data in local
storage via the browser using IndexedDB. This allows us to create
offline applications.
The two databases are both “master” copies of
the data.
PouchDB is a local JavaScript implementation of CouchDB.
I still need a better answer than my partial notes towards a solution!
Yes, this type of service worker is the correct one to use for saving form data offline.
I have now edited it and understood it better. It caches the form data, and loads it on the page for the user to see what they have entered.
It is worth noting that the paths to the library files will need editing to reflect your local directory structure, e.g. in my setup:
importScripts('/js/lib/ServiceWorkerWare.js');
importScripts('/js/lib/localforage.js');
The script is still failing when offline, however, as it isn't caching the library files. (Update to follow when I figure out caching)
Just discovered an extra debugging tool for service workers (apart from the console): chrome://serviceworker-internals/. In this, you can start or stop service workers, view console messages, and the resources used by the service worker.
I tried to update one entity in my angularjs client using breezejs library. After calling saveChanges(), it can actually save back in the server and fetched on the client. However, the server did not return the response back. The saveResult.entities is undefined and pop up an error for me. When I took a look at the docs, it mentions 'Some service APIs do not return information about every saved entity. If your server doesn't return such information, you should add the pre-save, cached entity to saveResult.entities yourself'. Could anyone provide an example of how to do this?
This is the code when i am trying to do an update.
manager.saveChanges(entitiesToSave, null, (saveResult) => {
const savedRes = saveResult;
savedRes.entities = entitiesToSave;
return savedRes;
}).then(saveSucceeded);
On the server, you would need to construct the response for an update similar to the way it is for a create:
response.setContent(...); // entities
response.setStatusCode(HttpStatusCode.OK.getStatusCode());
response.setHeader(HttpHeader.CONTENT_TYPE, responseFormat.toContentTypeString());