I’m implementing an app that makes uses of EventEmitter. My aim is to use it on both client and server. But strangely, emitting an event on the server does not work:
Emitter.emit('SomeEvent', {
user,
document,
}
);
The above will work on the client, but not on the server.
I’ve tried importing the event like Emitter = new (require('events').EventEmitter);
I’ve also tried to import a file with
import EventEmitter from 'events';
class ClassEmitter extends EventEmitter {}
const Emitter = new ClassEmitter();
export default Emitter;
My aim is to emit such an event after each database query on the server. I am using apollo and graphql.
Any idea on this would be very thankful.
Related
I need to forward a header from the browser to an external API I call from the server side.
The external API is called from getServerSideProps and API routes.
I was thinking about implementing some sort of a request context (using AsyncLocalStorage for example) that I can access from anywhere in the server side code.
That way I could create a middleware that will save the header to the context, and in the external API client I'll fetch it from the context and add it to the requests.
For example:
// context.ts
export const context = new AsyncLocalStorage<string>();
// middleware.ts
export function middleware(request: NextRequest) {
const store = request.headers[SOME_HEADER];
return context.run(store, () => NextResponse.next());
}
// client.ts
axios.post(EXTERNAL_API, DATA, {
headers: {
SOME_HEADER: context.getStore()
}
}).then(...)
Currently I simply send it as a parameter which is pretty tedious.
Is there a way of achieving it?
I tried adding async_hooks to my project but it got really messy when I tried to build the project.
I'm using localStorage on the server and it works fine locally. But when I deployed my code to Deno deploy is not defined
Do I need to import the localStorage? I Deno.com I couldn't find any docs talking about localStorage so maybe that feature is not supported yet. In that case, where can I deploy my code to use it? Thanks
import {Handlers, PageProps} from "$fresh/server.ts";
interface Data {
email: string[]
}
export const handler: Handlers<Data> = {
GET(_req, ctx) {
const emailsStorage = localStorage.getItem("email");
const email = emailsStorage ? JSON.parse(emailsStorage) : [];
console.log(email);
return ctx.render({ email });
},
};
export default function EmailPage({ data }: PageProps<Data>) {
const { email } = data;
return (
<main>
<h1>Emails</h1>
<ul>
{email.map((email) => (
<li>{email}</li>
))}
</ul>
</main>
);
}
The full list of available APIs is here (note that localStorage is not listed).
Deploy does not offer any persistent data storage mechanism. After your deployed code finishes executing in response to a request, all of the JS memory is destroyed, so if you want to work with mutable data that persists between requests, then you'll have to store that data yourself elsewhere — e.g. by sending the data in a network request to another server / hosted database / etc. and then requesting it when you need it.
The docs include several "persist data" tutorials that you can use as a guide/reference in order to learn.
You can persist data in local storage by creating a virtual local Storage by using this code.
import { installGlobals } from "https://deno.land/x/virtualstorage#0.1.0/mod.ts";
installGlobals();
localStorage.getItem("email") will work on Deno Deploy also.
I'm using Redux to manage state and Apollo to execute graphQL queries.
I create an Apollo client that should be accessible from various React components.
import { ApolloClient } from 'apollo-client';
import { HttpLink } from 'apollo-link-http';
import { InMemoryCache } from 'apollo-cache-inmemory';
const link = new HttpLink({
uri: getGraphqlEndpointUrl,
headers: {
'x-api-key': getApiKey(),
'Authorization': jwtToken,
},
});
const client = new ApolloClient({
link: link,
cache: new InMemoryCache(),
});
How do I do this with Redux? Do I store the client in a variable in the Redux store? That seems a bit strange to me, but not unreasonable. Is there a better way though?
Only serializable objects should be stored through redux -- functions or objects that have functions as properties do not belong in a redux store. If you need to reference the Apollo client outside of the component hierarchy of your React app, just create a module that exports the client object itself (not a function that creates a client). Then you can just import the client whereever (including the code that includes your ApolloProvider) and all your code will point at the same instance of the client (and the same cache).
It's important that the module for your client export the instantiated client itself -- if you export a function that creates the client, you'll be recreating it each time you import it.
How can I properly simulate a cloud function locally so that it has all data as when being invoked on firebase servers? (e.g. the context.auth)
I am serving my project with firebase serve, it runs ok on http://localhost:5000/, however, my cloud functions are being called from https://us-central1-<my-app>.cloudfunctions.net/getUser. (The function is not even deployed.)
To avoid XY problem, I am trying to debug my function, but calling it from firebase shell results in context.auth being undefined, same when calling via postman from http://localhost:5000/<my-app>/us-central1/getUser.
This is my ./functions/src/index.ts file
import * as functions from 'firebase-functions'
import admin from 'firebase-admin'
import { inspect } from 'util'
admin.initializeApp()
export const getUser = functions.https.onCall((data, context) => {
console.debug('== getUser called =========================================')
console.log('getUser', inspect(data), inspect(context.auth))
return admin.database().ref('userRights/admin').child(context.auth.uid).once('value', snapshot => {
console.log(snapshot.val())
if (snapshot.val() === true) {
return 'OK'
// return {status: 'OK'}
} else {
return 'NOK'
// return {status: 'error', code: 401, message: 'Unauthorized'}
}
})
})
file ./firebase.functions.ts
import { functions } from '~/firebase'
export const getUser = functions.httpsCallable('getUser')
Consumer ./src/pages/AdminPanel/index.tsx
import { getUser } from '~/firebase.functions'
//...
getUser({myDataX: 'asd'}).then(response => console.debug('response', response))
UPDATE - April/2021
As of April/2021, method useFunctionsEmulator has been deprecated. It is suggested to use method useEmulator(host, port) instead.
Original post:
By default, firebase serve sends queries to CLOUD function instead of localhost, but it is possible to change it to to point to localhost.
#gregbkr found a workaround for that at this github thread.
You basically add this after firebase initialization script (firebase/init.js) in html head.
<script>
firebase.functions().useFunctionsEmulator("http://localhost:5001");
</script>
Make sure to REMOVE it when deploying to SERVER
There is currently no support for local testing of callable functions like this. The team is working on a way for you to specify the URL endpoint of a callable function so that you can redirect it to a different location for testing.
Just found a workaround.
using fiddlers AutoResponder to redirect the function call to the local served function.
step 1
copy the target url of the function from the client
step 2
copy the local served function url
step 3
active the auto respoder and use the following rules
(the second rule is also importent to allow all outher requests
That worked for me, thank you #GorvGoyl!
script src="/__/firebase/init.js?useEmulator=true"></script
For bdd CRUD i write my Collection.insert , update, etc in a ValidatedMethod (mdg:validated-method) and call these methods from the client.
// /object/methods.js
export const insertObject = new ValidatedMethod({
name: 'insertObject',
run({object}) {
ObjectCollection.insert(object);
},
});
// /object/view.js
import {insertObject} from './methods.js'
insertObject.call(object , callback());
Is the bdd operation code protected (not on the client) by the used of Validatedmethod? Despise the import of the file.
Or do i need to put bdd code in a /server directory?
It bugs me cause on https://github.com/meteor/todos the crud methods are not in a /server folder, exposing them to the client...
note: unsecure package is removed.
If you import a method to client code, that method will be visible to client side. To avoid that you could just use Meteor.call or Meteor.apply to execute the method.