Cease the interval once the array is devoid of elements

Question

Cease the interval once the array is devoid of elements

I'm currently working on simulating typing effects for incoming server messages by adding an interval to the output.

Here's what I have so far:

const stream = interval(1000)
  .pipe(
  map((): Message => {
    return messages.pop();
  })
);

this.feed = merge(
  stream,
  this.local
).pipe(
  scan((acc, x) => [...acc, x], [])
);

However, I'm looking to stop the interval once my 'messages' array is empty. I've been trying to implement .TakeWhile without much success. Can anyone offer assistance with this issue?

Thank you in advance.

angular typescript kendo-ui rxjs conversational-ui

Answer 1

Answer №1

To implement takeWhile effectively, you can utilize the following code snippet:

const stream = interval(1000)   
  .pipe(
     takeWhile(() => messages.length > 0),
     map(() => messages.pop()),   
  );

I have created a demonstration on stackblitz for your reference: https://stackblitz.com/edit/typescript-sq6wxb?file=index.ts

Answer 2

To implement takeWhile effectively, you can utilize the following code snippet:

const stream = interval(1000)   
  .pipe(
     takeWhile(() => messages.length > 0),
     map(() => messages.pop()),   
  );

I have created a demonstration on stackblitz for your reference: https://stackblitz.com/edit/typescript-sq6wxb?file=index.ts

Answer 3

Answer №2

It seems like the issue you're facing is that stream continues to emit even when messages is empty.

To resolve this, you can utilize the takeWhile operator in your stream:

const stream = interval(1000).pipe(
  map((): Message => messages.pop()),
  takeWhile(Boolean),
);

When messages becomes empty, it will return undefined, which evaluates to false. This is why using takeWhile(Boolean) will help complete the stream accordingly.

Answer 4

It seems like the issue you're facing is that stream continues to emit even when messages is empty.

To resolve this, you can utilize the takeWhile operator in your stream:

const stream = interval(1000).pipe(
  map((): Message => messages.pop()),
  takeWhile(Boolean),
);

When messages becomes empty, it will return undefined, which evaluates to false. This is why using takeWhile(Boolean) will help complete the stream accordingly.

Cease the interval once the array is devoid of elements

Answer №1

Answer №2

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