cheapstate v1.0.0

CheapState

A namespaceable localStorage pub/sub utility for the masses.

Event-driven, persistent state management built on top of localStorage and sessionStorage.

Examples

Instantiantiating:

const pointsStorage = new CheapState('points');
pointsStorage.set('paceaux', 10);

Optionally, instantiate with sessionStorage:

const pointsStorage = new CheapState('points', 'session');

Saving & Getting items

pointsStorage.set('frank', 10);
pointsStorage.get('frank');// 10

Saving an object

pointsStorage.setObject({
    'frank': 10,
    'joe': 20,
    'sally': 30
});
pointsStorage.get('frank'); // 10

Saving a map

const points = new Map([
    ['frank', 10],
    ['joe', 20],
    ['sally', 30]
]);

pointsStorage.setObject(points);
pointsStorage.get('frank'); // 10

Deleting and Clearing

Delete an item

pointsStorage.delete('sally');

Clearing the storage

pointsStorage.clear();

Adding & subscribing

const badgeEls = document.querySelectorAll('.badge');
badgeEls.forEach((badgeEl) => {
    updateBadge(badgeEl)

    // add a subscriber
    pointsStorage.subscribe((payload) => {
        // does the key match this element's key?
        if (payload.key === badgeEl.dataset.key) {
            // update it!
            updateBadge(badgeEl);
        }
    });
});

API

CheapState

Global Class

new CheapState(namespace, type)

Parameters

Static Methods

getNameSpacedKeyName(namespace, keyname)

Parameters

Returns

string with with <namespace>.<keyname>.

convertValue(value)

Makes a value safe to be stored in localStorage.

Parameters

Returns

string version of the value.

unconvertValue(value)

Converts a string into a JavaScript value;

Parameters

Returns

any version of the value.

registerNamespace(namespace, storage)

Adds a namespace to storage

Instance Members

namespace

string the namespace for the CheapState instance.

observers

Function[] a list of the observers for the CheapState instance.

namespaces

string[] a list of the namespaces in storage.

storage

Storage either localStorage or sessionStorage.

items

Map<'string', any> all of the items in storage for the given namespace.

size

number the number of items in storage for the given namespace.

length

number the number of items in storage for the given namespace. (alias for size)

Instance Methods

hasNamespace(namespace)

Determines if a namespace already exists

Parameters

Returns

boolean if the namespace exists.

set(key, value)

Sets an item into storage

Parameters

setObject(dataObject)

Sets an object's keys and values into storage.

Parameters

get(key)

Gets an item from storage.

Parameters

Returns

any the value of the key.

has(key)

Determines if an item exists in storage.

Parameters

Returns

boolean whether the key exists.

delete(key)

Deletes an item from storage.

Parameters

clear()

Deletes all items in the namespaced storage.

Parameters

subscribe(observable)

Adds a function to observables; allows it to receive a payload when storage changes

Parameters

unsubscribe(observable)

Removes a function from observables

notify(data)

Sends a payload to the observer