takewhile.md

Rx.Observable.prototype.takeWhile(predicate, [thisArg])

Ⓢ

Returns elements from an observable sequence as long as a specified condition is true.

Arguments

1. predicate (Function): A function to test each source element for a condition. The callback is called with the following information:
   1. the value of the element
   2. the index of the element
   3. the Observable object being subscribed
2. [thisArg] (Any): Object to use as this when executing callback.

Returns

(Observable): An observable sequence that contains the elements from the input sequence that occur before the element at which the test no longer passes.

Example

// With a predicate
var source = Rx.Observable.range(1, 5)
    .takeWhile(function (x) { return x < 3; });

var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x);
    },
    function (err) {
        console.log('Error: ' + err);
    },
    function () {
        console.log('Completed');
    });

// => Next: 0
// => Next: 1
// => Next: 2
// => Completed

Location

File:

• /src/core/linq/observable/takewhile.js

Dist:

• rx.all.js
• rx.all.compat.js
• rx.js
• rx.compat.js
• rx.lite.js
• rx.lite.compat.js

Prerequisites:

• None

NPM Packages:

• rx

NuGet Packages:

• RxJS-All
• RxJS-Main
• RxJS-Lite

Unit Tests:

• /tests/observable/takewhile.js