use-iterator
    TypeScript icon, indicating that this package has built-in type declarations

    1.1.1 • Public • Published

    use-iterator

    npm CI codecov

    React hooks collection for JavaScript's Iterator/generator.

    useForAwaitOf(asyncIterable)

    Subscribes to the asyncIterable specified in the argument and as soon as a promise is resolved, immediately starts to await the next promise.

    This is similar to for-await-of syntax of JavaScript, but the results are wrapped in React APIs so components will be updated whenever the result changes.

    import { on } from 'events-to-async';
    
    const changeEvent = on((handler) => {
      const elm = document.getElementById('text_field');
      elm?.addEventListener('change', handler);
      return () => elm?.removeEventListener('change', handler);
    });
    
    const App = () => {
      // subscribe to the change events from #text_field
      const result = useForAwaitOf(changeEvent);
      
      // latest change event from #text_field
      return (
        <span>{result.value}</span>
      )
    }

    Note that this example uses an additional module events-to-async to convert Event objects into AsyncIterator.

    useGenerator(generator, deps)

    Wraps generator function into a React state. You can call next() to retrieve the next value, and read the latest value from the iterator via value.

    const App = () => {
      const result = useGenerator<string>(function* () {
        yield 'Let\'s get started';
        yield 'Choose your username';
        yield 'Upload the avatar';
      }, []);
    
      if (result.done) {
        return <div>Tutorial completed!</div>;
      }
    
      return (
        <div>
          <h2>{result.value}</h2>
    
          <button onClick={() => result.next()}>
            Next
          </button>
        </div>
      )
    }

    useAsyncGenerator(generator, deps)

    Wraps async generator function into a React state. You can call next() to retrieve the next value, and read the latest value from the iterator via value.

    This is similar to useGenerator described above, but with async you can return Promises from the generator. This would be useful for sequential network requests such as Web APIs with pagination.

    const App = () => {
      const result = useAsyncGenerator<string>(function* () {
        yield fetch('https://example.com?page=1');
        yield fetch('https://example.com?page=2');
        yield fetch('https://example.com?page=3');
      }, []);
    
      if (result.loading) {
        return <span>Loading...</span>
      }
    
      return (
        <div>
          <ul>
            {result.value.map((item) => (
              <li>...</li>
            ))}
          </ul>
    
          <button onClick={()) => result.next()}>
            Next
          </button>
        </div>
      );
    };

    useIterable(iterable)

    Wraps iterable into a React state. You can call next() to retrieve the next value, and read the latest value from the iterator via value.

    Argument can be any object that implements [Symbol.iterator] protocol such as String and Array.

    const result = useIterable("abcd");
    
    result.next();
    result.value === 'a';
    
    result.next();
    result.value === 'b';

    useAsyncIterable(asyncIterable)

    Wraps async iterable into a React state. You can call next() to retrieve the next value, and read the latest value from the iterator via value.

    Argument can be any object that implements [Symbol.asyncIterator] protocol.

    const result = useAsyncIterable({
      [Symbol.asyncIterator]() {
        return {
          i: 0,
          next() {
            if (this.i < 3) {
              return Promise.resolve({ value: this.i++, done: false });
            }
    
            return Promise.resolve({ done: true });
          }
        };
      }
    });
    
    result.next();
    result.loading; // === true while loading
    result.value === 1;

    useIterator(iterator)

    A low-level hook for useIterable and useGenerator. Accepts iterator object and returns a reactive state and a dispatcher.

    const result = useIterator({
      next: () {...},
      return: () {...},
      throw: () {...},
    });

    useAsyncIterator(iterator)

    A low-level hook for useAsyncIterable and useAsyncGenerator. Accepts async iterator object and returns a reactive state and a dispatcher.

    const result = useAsyncIterator({
      next: () {...},
      return: () {...},
      throw: () {...},
    });

    Keywords

    none

    Install

    npm i use-iterator

    DownloadsWeekly Downloads

    4

    Version

    1.1.1

    License

    MIT

    Unpacked Size

    60.3 kB

    Total Files

    34

    Last publish

    Collaborators

    • neetshin