65 lines
2.3 KiB
JavaScript
65 lines
2.3 KiB
JavaScript
|
"use strict";
|
||
|
|
var distinctUntilChanged_1 = require('./distinctUntilChanged');
|
||
|
|
/* tslint:enable:max-line-length */
|
||
|
|
/**
|
||
|
|
* Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from the previous item,
|
||
|
|
* using a property accessed by using the key provided to check if the two items are distinct.
|
||
|
|
*
|
||
|
|
* If a comparator function is provided, then it will be called for each item to test for whether or not that value should be emitted.
|
||
|
|
*
|
||
|
|
* If a comparator function is not provided, an equality check is used by default.
|
||
|
|
*
|
||
|
|
* @example <caption>An example comparing the name of persons</caption>
|
||
|
|
*
|
||
|
|
* interface Person {
|
||
|
|
* age: number,
|
||
|
|
* name: string
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* Observable.of<Person>(
|
||
|
|
* { age: 4, name: 'Foo'},
|
||
|
|
* { age: 7, name: 'Bar'},
|
||
|
|
* { age: 5, name: 'Foo'},
|
||
|
|
* { age: 6, name: 'Foo'})
|
||
|
|
* .distinctUntilKeyChanged('name')
|
||
|
|
* .subscribe(x => console.log(x));
|
||
|
|
*
|
||
|
|
* // displays:
|
||
|
|
* // { age: 4, name: 'Foo' }
|
||
|
|
* // { age: 7, name: 'Bar' }
|
||
|
|
* // { age: 5, name: 'Foo' }
|
||
|
|
*
|
||
|
|
* @example <caption>An example comparing the first letters of the name</caption>
|
||
|
|
*
|
||
|
|
* interface Person {
|
||
|
|
* age: number,
|
||
|
|
* name: string
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* Observable.of<Person>(
|
||
|
|
* { age: 4, name: 'Foo1'},
|
||
|
|
* { age: 7, name: 'Bar'},
|
||
|
|
* { age: 5, name: 'Foo2'},
|
||
|
|
* { age: 6, name: 'Foo3'})
|
||
|
|
* .distinctUntilKeyChanged('name', (x: string, y: string) => x.substring(0, 3) === y.substring(0, 3))
|
||
|
|
* .subscribe(x => console.log(x));
|
||
|
|
*
|
||
|
|
* // displays:
|
||
|
|
* // { age: 4, name: 'Foo1' }
|
||
|
|
* // { age: 7, name: 'Bar' }
|
||
|
|
* // { age: 5, name: 'Foo2' }
|
||
|
|
*
|
||
|
|
* @see {@link distinct}
|
||
|
|
* @see {@link distinctUntilChanged}
|
||
|
|
*
|
||
|
|
* @param {string} key String key for object property lookup on each item.
|
||
|
|
* @param {function} [compare] Optional comparison function called to test if an item is distinct from the previous item in the source.
|
||
|
|
* @return {Observable} An Observable that emits items from the source Observable with distinct values based on the key specified.
|
||
|
|
* @method distinctUntilKeyChanged
|
||
|
|
* @owner Observable
|
||
|
|
*/
|
||
|
|
function distinctUntilKeyChanged(key, compare) {
|
||
|
|
return distinctUntilChanged_1.distinctUntilChanged(function (x, y) { return compare ? compare(x[key], y[key]) : x[key] === y[key]; });
|
||
|
|
}
|
||
|
|
exports.distinctUntilKeyChanged = distinctUntilKeyChanged;
|
||
|
|
//# sourceMappingURL=distinctUntilKeyChanged.js.map
|