linkwait() operator

In situations that you want to conduct some (potentially asynchronous) task based on incoming requests, and it is important to wait for this task to finish before moving down the observable sequence, you can use wait() operator:

1import { wait, validate, respond } from 'rxxpress';

2

3

4const emailRegex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

5

6

7router.put('/users/update/email')

8.pipe(

9  authenticate(),                                   // --> authenticate the user

10  validate(({req}) => emailRegex.test(req.body)),   // --> validate the new email address

11  wait(async ({req}) => {                           // --> save the new email address

12    await users.update(req._.user.id, {             // --> save the new email address

13      email: req.body                               // --> save the new email address

14    })                                              // --> save the new email address

15  }),                                               // --> save the new email address

16  respond(() => 'Updated!')                         // --> respond

17)

18.subscribe();

info NOTICE

If you do not need to wait for the task before moving along, it is more efficient to use RxJs's tap operator instead.

linkObservable Functions

Similar to check() and respond(), you can provide synchronous functions or functions returning observables. In case your wait function returns an observable, the wait() operator will wait for the first value emitted by that observable:

1router.post('/')

2.pipe(

3  // ...

4  wait(({req}) => ajax({           // --> trigger user's webhook

5    method: 'POST',                // --> trigger user's webhook

6    url: req._.user.webhook,       // --> trigger user's webhook

7    body: ...                      // --> trigger user's webhook

8  })),                             // --> trigger user's webhook

9  respond(() => 'Webhook Triggered!')

10)

linkPacket Flow

wait() operator waits until its task is finished and then passed incoming packets down the observable sequence.