Terminate a graphql request from Apollo Link - graphql

I have an ApolloLink setup for the AWSAppSyncClient in my React project to check if the user is authorized to make the graphql request. If the user is not authorized then, link should not invoke the forward method rather just return an Error for unauthorized access (making it a terminating link).
I tried returning the plain Error response (also tried it with Observable.of), but the request doesn't resolves but keeps on to retry the request on an endless loop.
Need a better solution to implement it.
const authLink = new ApolloLink((operation, forward) => {
const { operationName } = operation;
if (checkIfNotAuthorized(operationName)) {
const error = new Error('Access denied');
return { errors: [error], data: null };
}
return forward(operation);
});

Related

Resending a graphql mutation after re-authenticating using Apollo's useMutation

I have an issue where we're using apollo client and specifically the useMutation react hook to perform mutation calls to our GraphQL Server.
At certain times, the server may return a 401 unauthorized response - at which point, we can make a call to special endpoint which re-authenticates the client and refreshes the cookie/token whatever.
I want to be able to re-run the same mutation again once the client is re-authenticated. So basically I would like to know if it is possible to do the following:
useMutation --> Receive 401 Unauthorized --> call to refresh token --> rerun same initial mutation
This is how our useMutation looks like:
const [mutationFunction, { data, ...rest }] = useMutation(query, {
onError(_err: any) {
const networkError = error?.networkError as any;
if (networkError?.statusCode === 401 && !refreshFailed) {
// eslint-disable-next-line prefer-destructuring
loading = true;
error = undefined;
fetch('/authentication/refresh', {
method: 'POST',
headers: { 'Content-Type': 'application/json' }
})
.then(response => response.json())
.then(token => {
localStorage.setItem(jwtLocalStorageKey, token);
// re fetch here
})
.catch(() => {
refreshFailed = true;
});
} else {
showAlert(_err.message, 'error');
}
}
});
and this is how we call it currently:
const {
mutationFunction: updateTournamentUserMutation,
loading: updateTournamentUserLoading,
error: updateTournamentUserError,
data: updateTournamentUserData
} = useMutationHook(gqlUpdateTournamentUser);
updateTournamentUserMutation({ variables: { input } });
Because we're using hooks and the way we're using it above, I'm not entirely sure how we can save or reuse the same data that is initially sent in the first mutation (that is the mutation parameters)
Is it possible to do so using the current way we're doing it?

How do I blend a promise with an observable?

I'm having trouble promises and observables. I have a handful of http requests which are defined in a package using promises. In the rest of my code I am using observables for various things, including other http calls. In one particular section I am checking to see if the user's bearer token is expired and if so then I get a new token and then proceed with the rest of the call.
if (!token || token.exp < Math.round((new Date()).getTime() / 1000)) {
from(this._store.refreshBearerToken())
.pipe(flatMap(resp => {
let newToken = resp.data;
newToken.exp = (new Date()).getTime() / 1000 + newToken.expires_in;
localStorage.setItem('token', JSON.stringify(newToken))
options = options || {};
options.headers = new HttpHeaders({
"Authorization": `${newToken.token_type} ${newToken.access_token}`,
"Content-Type": "application/json"
});
return this._http$.request<T>(method, url, options as Object).pipe(share());
}));
}
Bearer Token method:
async refreshBearerToken() {
const response = await this._q2.sources.requestExtensionData({
route: "refreshBearerToken"
});
console.log(response);
return response;
}
Since this._store.refreshBearerToken returns a promise I wrapped the call in a from to convert it to an observable. This compiles but when it runs I get "Cannot read property 'pipe' of undefined".
How can I convert this promise to an observable so that I can refresh the token and then continue with the rest of the call?
Edit:
I am importing from via import { Observable, from } from "rxjs";.
So, I thought the error was coming from the line .pipe(flatMap(resp =>... but I was wrong. The error is coming from the method which is calling this.
GetInitialLinkList(): Observable<Institution[]>
{
let base = { 'MemberId': localStorage.getItem('memberId') };
let ins = localStorage.getItem("initialInstitutionList");
if (ins)
{
return of(JSON.parse(ins));
}
return this._settingsService.get().pipe(
flatMap(settings =>
{
this._settings = settings;
return this._api.request<Institution[]>("Post", `${this._settings.mea}/GetInitialLinkList`, { body: base })
.pipe(
retry(1),
catchError(this.handleError)
)
.pipe(flatMap(instList =>
{
localStorage.setItem("initialInstitutionList", JSON.stringify(instList));
return of(instList);
}))
}));
}
and that is being subscribed to inside my component:
private GetLinkList()
{
this.showWaiting.emit(true);
this._data.GetInitialLinkList().subscribe((result) =>
{
this.initialList = result;
this.showWaiting.emit(false);
});
}
From what Brandon said (I forgot to return /facepalm...) I added the return so I have return from(this._store.refreshBearerToken()) which changed my error to
ERROR Error Code: undefined
Message: You provided an invalid object where a stream was expected. You can provide an Observable, Promise, Array, or Iterable.
defaultErrorLogger # core.js:6014
Can you show the actual error and the line in the code that the error occurs on? Also show where and how you import from.
I notice your code snippet does not return the observable it builds up via from(...).pipe(...) nor does it subscribe to it. It might help to show how your code actually uses this observable.

GraphQL subscription using server-sent events & EventSource

I'm looking into implementing a "subscription" type using server-sent events as the backing api.
What I'm struggling with is the interface, to be more precise, the http layer of such operation.
The problem:
Using the native EventSource does not support:
Specifying an HTTP method, "GET" is used by default.
Including a payload (The GraphQL query)
While #1 is irrefutable, #2 can be circumvented using query parameters.
Query parameters have a limit of ~2000 chars (can be debated)
which makes relying solely on them feels too fragile.
The solution I'm thinking of is to create a dedicated end-point for each possible event.
For example: A URI for an event representing a completed transaction between parties:
/graphql/transaction-status/$ID
Will translate to this query in the server:
subscription TransactionStatusSubscription {
status(id: $ID) {
ready
}
}
The issues with this approach is:
Creating a handler for each URI-to-GraphQL translation is to be added.
Deploy a new version of the server
Loss of the flexibility offered by GraphQL -> The client should control the query
Keep track of all the end-points in the code base (back-end, front-end, mobile)
There are probably more issues I'm missing.
Is there perhaps a better approach that you can think of?
One the would allow a better approach at providing the request payload using EventSource?
Subscriptions in GraphQL are normally implemented using WebSockets, not SSE. Both Apollo and Relay support using subscriptions-transport-ws client-side to listen for events. Apollo Server includes built-in support for subscriptions using WebSockets. If you're just trying to implement subscriptions, it would be better to utilize one of these existing solutions.
That said, there's a library for utilizing SSE for subscriptions here. It doesn't look like it's maintained anymore, but you can poke around the source code to get some ideas if you're bent on trying to get SSE to work. Looking at the source, it looks like the author got around the limitations you mention above by initializing each subscription with a POST request that returns a subscription id.
As of now you have multiple Packages for GraphQL subscription over SSE.
graphql-sse
Provides both client and server for using GraphQL subscription over SSE. This package has a dedicated handler for subscription.
Here is an example usage with express.
import express from 'express'; // yarn add express
import { createHandler } from 'graphql-sse';
// Create the GraphQL over SSE handler
const handler = createHandler({ schema });
// Create an express app serving all methods on `/graphql/stream`
const app = express();
app.use('/graphql/stream', handler);
app.listen(4000);
console.log('Listening to port 4000');
#graphql-sse/server
Provides a server handler for GraphQL subscription. However, the HTTP handling is up to u depending of the framework you use.
Disclaimer: I am the author of the #graphql-sse packages
Here is an example with express.
import express, { RequestHandler } from "express";
import {
getGraphQLParameters,
processSubscription,
} from "#graphql-sse/server";
import { schema } from "./schema";
const app = express();
app.use(express.json());
app.post(path, async (req, res, next) => {
const request = {
body: req.body,
headers: req.headers,
method: req.method,
query: req.query,
};
const { operationName, query, variables } = getGraphQLParameters(request);
if (!query) {
return next();
}
const result = await processSubscription({
operationName,
query,
variables,
request: req,
schema,
});
if (result.type === RESULT_TYPE.NOT_SUBSCRIPTION) {
return next();
} else if (result.type === RESULT_TYPE.ERROR) {
result.headers.forEach(({ name, value }) => res.setHeader(name, value));
res.status(result.status);
res.json(result.payload);
} else if (result.type === RESULT_TYPE.EVENT_STREAM) {
res.writeHead(200, {
'Content-Type': 'text/event-stream',
Connection: 'keep-alive',
'Cache-Control': 'no-cache',
});
result.subscribe((data) => {
res.write(`data: ${JSON.stringify(data)}\n\n`);
});
req.on('close', () => {
result.unsubscribe();
});
}
});
Clients
The two packages mentioned above have companion clients. Because of the limitation of the EventSource API, both packages implement a custom client that provides options for sending HTTP Headers, payload with post, what the EvenSource API does not support. The graphql-sse comes together with it client while the #graphql-sse/server has companion clients in a separate packages.
graphql-sse client example
import { createClient } from 'graphql-sse';
const client = createClient({
// singleConnection: true, use "single connection mode" instead of the default "distinct connection mode"
url: 'http://localhost:4000/graphql/stream',
});
// query
const result = await new Promise((resolve, reject) => {
let result;
client.subscribe(
{
query: '{ hello }',
},
{
next: (data) => (result = data),
error: reject,
complete: () => resolve(result),
},
);
});
// subscription
const onNext = () => {
/* handle incoming values */
};
let unsubscribe = () => {
/* complete the subscription */
};
await new Promise((resolve, reject) => {
unsubscribe = client.subscribe(
{
query: 'subscription { greetings }',
},
{
next: onNext,
error: reject,
complete: resolve,
},
);
});
;
#graphql-sse/client
A companion of the #graphql-sse/server.
Example
import {
SubscriptionClient,
SubscriptionClientOptions,
} from '#graphql-sse/client';
const subscriptionClient = SubscriptionClient.create({
graphQlSubscriptionUrl: 'http://some.host/graphl/subscriptions'
});
const subscription = subscriptionClient.subscribe(
{
query: 'subscription { greetings }',
}
)
const onNext = () => {
/* handle incoming values */
};
const onError = () => {
/* handle incoming errors */
};
subscription.susbscribe(onNext, onError)
#gaphql-sse/apollo-client
A companion package of the #graph-sse/server package for Apollo Client.
import { split, HttpLink, ApolloClient, InMemoryCache } from '#apollo/client';
import { getMainDefinition } from '#apollo/client/utilities';
import { ServerSentEventsLink } from '#graphql-sse/apollo-client';
const httpLink = new HttpLink({
uri: 'http://localhost:4000/graphql',
});
const sseLink = new ServerSentEventsLink({
graphQlSubscriptionUrl: 'http://localhost:4000/graphql',
});
const splitLink = split(
({ query }) => {
const definition = getMainDefinition(query);
return (
definition.kind === 'OperationDefinition' &&
definition.operation === 'subscription'
);
},
sseLink,
httpLink
);
export const client = new ApolloClient({
link: splitLink,
cache: new InMemoryCache(),
});
If you're using Apollo, they support automatic persisted queries (abbreviated APQ in the docs). If you're not using Apollo, the implementation shouldn't be too bad in any language. I'd recommend following their conventions just so your clients can use Apollo if they want.
The first time any client makes an EventSource request with a hash of the query, it'll fail, then retry the request with the full payload to a regular GraphQL endpoint. If APQ is enabled on the server, subsequent GET requests from all clients with query parameters will execute as planned.
Once you've solved that problem, you just have to make a server-sent events transport for GraphQL (should be easy considering the subscribe function just returns an AsyncIterator)
I'm looking into doing this at my company because some frontend developers like how easy EventSource is to deal with.
There are two things at play here: the SSE connection and the GraphQL endpoint. The endpoint has a spec to follow, so just returning SSE from a subscription request is not done and needs a GET request anyway. So the two have to be separate.
How about letting the client open an SSE channel via /graphql-sse, which creates a channel token. Using this token the client can then request subscriptions and the events will arrive via the chosen channel.
The token could be sent as the first event on the SSE channel, and to pass the token to the query, it can be provided by the client in a cookie, a request header or even an unused query variable.
Alternatively, the server can store the last opened channel in session storage (limiting the client to a single channel).
If no channel is found, the query fails. If the channel closes, the client can open it again, and either pass the token in the query string/cookie/header or let the session storage handle it.

abort all Axios requests when change route use vue-router

how can i abort / cancel Axios request before complete when i change route use
vue-router.
when user open page it automatically send axios request to get some data,
but user don't waiting to get response then he is changing route by vue-router
it will be a lot of Axios requests
so is there any solve to my problem
Update: Axios (0.22.0+)
CancelToken is now deprecated. Check #m0r answer for updated solution using AbortController. Here is the link from the official documentation:
https://axios-http.com/docs/cancellation
Original answer
Basically you have to generate a global cancel token
const CancelToken = axios.CancelToken;
const source = CancelToken.source();
and use it in all your requests by passing it in the config parameter
GET request:
axios.get('/user/12345', {
cancelToken: source.token
}).catch(function(thrown) {
if (axios.isCancel(thrown)) {
console.log('Request canceled', thrown.message);
} else {
// handle error
}
});
POST request:
axios.post('/user/12345', {
name: 'new name'
}, {
cancelToken: source.token
})
Then, within a vue-router beforeEach navigation guard you can cancel all requests using:
source.cancel('Operation canceled by the user.');
Here's the official axios guide for cancellation: https://github.com/axios/axios#cancellation
Answer from #fabruex is correct. I just wanted to add here that if you have lot of api calls then you have to pass cancellation token in each api call config. In order to reduce that code, you can create axios instance and add request interceptor which will add that common cancellation token and then you can assign a new value to token when cancellation is done or your route has changed.
// Some global common cancel token source
let cancelSource = axios.CancelToken.source();
// Request interceptor
export const requestInterceptor = config => {
config.cancelToken = cancelSource.token;
return config;
};
// Add request interceptor like this
const request = axios.create({ baseURL: SOME_URL });
request.interceptors.request.use(requestInterceptor);
// Now you can use this axios instance like this
await request.get('/users');
// and
await request.post('/users', data);
// When you will cancel
cancelSource.cancel('Your cancellation message');
// And all the api calls initiated by axios instance which has request interceptor will be cancelled.
Edit to answer #Suneet Jain
You can create a class and create an instance which you can update
class CancelToken {
constructor(initialValue) {
this.source = initialValue;
}
getSource() {
return this.source;
}
setSource(value) {
this.source = value;
}
cancel() {
this.source.cancel();
}
}
export const cancelSource = new CancelToken(axios.CancelToken.source());
You can import that instance cancelSource and call cancel when required e.g. when you logout, you can call to cancel all request which have cancellation token given by cancelSource.getSource()
So after logout
cancelSource.cancel('CANCELLED');
And when again user will login, set new cancellation token to this global instance
cancelSource.setSource(axios.CancelToken.source());
2022 Update | Axios (0.22.0+)
CancelToken is deprecated. AbortController should be used now in new projects. The implementation is cleaner.
const controller = new AbortController();
Pass the controller in the config parameter:
axios.get('/foo/bar', {
signal: controller.signal
}).then(function(response) {
//...
});
And to cancel the request, simply use:
controller.abort()
source : https://github.com/axios/axios#cancellation

Axios Reponse Interceptor : unable to handle an expired refresh_token (401)

I have the following interceptor on my axios reponse :
window.axios.interceptors.response.use(
response => {
return response;
},
error => {
let errorResponse = error.response;
if (errorResponse.status === 401 && errorResponse.config && !errorResponse.config.__isRetryRequest) {
return this._getAuthToken()
.then(response => {
this.setToken(response.data.access_token, response.data.refresh_token);
errorResponse.config.__isRetryRequest = true;
errorResponse.config.headers['Authorization'] = 'Bearer ' + response.data.access_token;
return window.axios(errorResponse.config);
}).catch(error => {
return Promise.reject(error);
});
}
return Promise.reject(error);
}
);
The _getAuthToken method is :
_getAuthToken() {
if (!this.authTokenRequest) {
this.authTokenRequest = window.axios.post('/api/refresh_token', {
'refresh_token': localStorage.getItem('refresh_token')
});
this.authTokenRequest.then(response => {
this.authTokenRequest = null;
}).catch(error => {
this.authTokenRequest = null;
});
}
return this.authTokenRequest;
}
The code is heavily inspired by https://github.com/axios/axios/issues/266#issuecomment-335420598.
Summary : when the user makes a call to the API and if his access_token has expired (a 401 code is returned by the API) the app calls the /api/refresh_token endpoint to get a new access_token. If the refresh_token is still valid when making this call, everything works fine : I get a new access_token and a new refresh_token and the initial API call requested by the user is made again and returned correctly.
The problem occurs when the refresh_token has also expired.
In that case, the call to /api/refresh_token returns a 401 and nothing happens. I tried several things but I'm unable to detect that in order to redirect the user to the login page of the app.
I found that in that case the if (!this.authTokenRequest) statement inside the _getAuthToken method returns a pending Promise that is never resolved. I don't understand why this is a Promise. In my opinion it should be null...
I'm a newbie with Promises so I may be missing something !
Thanks for any help !
EDIT :
I may have found a way much simpler to handle this : use axios.interceptors.response.eject() to disable the interceptor when I call the /api/refresh_token endpoint, and re-enable it after.
The code :
createAxiosResponseInterceptor() {
this.axiosResponseInterceptor = window.axios.interceptors.response.use(
response => {
return response;
},
error => {
let errorResponse = error.response;
if (errorResponse.status === 401) {
window.axios.interceptors.response.eject(this.axiosResponseInterceptor);
return window.axios.post('/api/refresh_token', {
'refresh_token': this._getToken('refresh_token')
}).then(response => {
this.setToken(response.data.access_token, response.data.refresh_token);
errorResponse.config.headers['Authorization'] = 'Bearer ' + response.data.access_token;
this.createAxiosResponseInterceptor();
return window.axios(errorResponse.config);
}).catch(error => {
this.destroyToken();
this.createAxiosResponseInterceptor();
this.router.push('/login');
return Promise.reject(error);
});
}
return Promise.reject(error);
}
);
},
Does it looks good or bad ? Any advice or comment appreciated.
Your last solution looks not bad. I would come up with the similar implementation as you if I were in the same situation.
I found that in that case the if (!this.authTokenRequest) statement inside the _getAuthToken method returns a pending Promise that is never resolved. I don't understand why this is a Promise. In my opinion it should be null...
That's because this.authTokenRequest in the code was just assigned the Promise created from window.axios.post. Promise is an object handling kind of lazy evaluation, so the process you implement in then is not executed until the Promise was resolved.
JavaScript provides us with Promise object as kind of asynchronous event handlers which enables us to implement process as then chain which is going to be executed in respond with the result of asynchronous result. HTTP requests are always inpredictable, because HTTP request sometimes consumes much more time we expect, and also sometimes not. Promise is always used when we use HTTP request in order to handle the asynchronous response of it with event handlers.
In ES2015 syntax, you can implement functions with async/await syntax to hanle Promise objects as it looks synchronous.

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