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ObservableMap
ObservableMap is an observable wrapper over a JavaScript Map. It allows Twist to detect when the contents of the map changes, so that reactivity can work as expected.
NOTE: an
ObservableMapis not currently iterable from JavaScript, unlike aMap- this capability will be added in future.
Constructor
The constructor can optionally be supplied a Map, or an object:
import { ObservableMap } from '@twist/core';
var map1 = new ObservableMap;
console.log(map1.size); // 0
var map2 = new ObservableMap({x: 1, y: 2});
console.log(map2.size); // 2
var map3 = new ObservableMap(new Map([ [ 'x', 1 ], [ 'y', 2 ] ]));
console.log(map3.size); // 2
Properties
| Property | Description |
|---|---|
length |
Alias for size |
size |
Returns the number of keys in the map |
Methods
| Method | Description |
|---|---|
clear() |
Removes all entries from the map |
delete() |
Deletes the entry under a given key |
entries() |
Returns a new Iterator object that contains the key/value pairs in the map |
forEach() |
Iterates over the entries in the map |
get() |
Returns the value stored for a given key |
has() |
Returns a Boolean indicating the presence of a given key |
keys() |
Returns a new Iterator object that contains the keys in the map |
set() |
Creates a new entry in the map |
values() |
Returns a new Iterator object that contains the values in the map |