@nrk/yr-data-store

A data object that supports storing and retrieving data with namespaced keys ('foo/bar/bat'), immutability, data fetching, and a flexible handler api for observation, side effects, computed values and more.

Usage

const dataStoreFactory = require("@nrk/yr-data-store").create;
const store = dataStoreFactory("fooStore", { foo: true, bar: false });

store.get("foo"); //=> true
store.set("foo/bar", { bat: true, boo: ["boo"] }, { immutable: true });
store.get("foo/bar/bat"); //=> true

API

create (id: String, data: Object, options: Object): DataStore|FetchableDataStore

Instance factory. Options include:

• handlers: Array array of tuples ([match: RegExp, handler: Function]) for passing to useHandler [default: null]. See handlers
• isFetchable: Boolean specify whether instance should be a FetchableDataStore that supports data fetching [default: false]. See FetchableDataStore
• isWritable: Boolean specify whether instance should be writable via set() [default: true]
• serialisableKeys: Object object listing keys and their serialisable state [default: {}]. See setSerialisabilityOfKey()

DataStore

setWriteable (value: Boolean)

Set the writeable state of a store. A read-only store will internally cache all calls to get(). Calling setWriteable() to toggle read/write state will invalidate the internal cache.

get (key: String, options: Object): *

Retrieve value stored at key. Empty key will return all data:

store.get("foo/bar/bat"); //=> true

getAll (keys: Array): Array

Batch version of get(). Accepts array of keys, and returns array of values:

store.getAll(["foo/bar/bat", "bar"]); //=> [true, false]

set (key: String, value: *, options: Object)

Store value at key:

store.set("bat", "bat");

options include:

• immutable: Boolean specify whether to mutate the underlying data object [default: true for browser, false for server]
• merge: Boolean specify whether to merge value into the underlying data object (true), or overwrite an existing key (false) [default: true]

setAll (keys: Object, options: Object)

Batch version of set(). Accepts hash of key:value pairs:

store.set({ bat: "bat", "foo/bar/bat": false });

options are same as for set().

reset (data: Object)

Reset/replace underlying data with data.

destroy ()

Destroy the instance.

setSerialisabilityOfKey (key: String, value: Boolean)

Specify serialisablity of key. Setting a key to false will exclude that key when stringifying:

store.setSerialisabilityOfKey("foo", false);
JSON.stringify(store); //=> { "bar": false, "bat": "bat"}

setSerialisabilityOfKeys (keys: Object)

Batch version of setSerialisabilityOfKey(). Accepts a hash of key:value pairs:

store.setSerialisabilityOfKeys({ foo: false, bat: false });
JSON.stringify(store); //=> { "bar": false }

dump (stringify: Boolean): Object|String

Retrieve all data as Object or String (if stringify argument is true).

fetch (key: String, url: String, options: Object): Promise

Retrieve value stored at key. If the stored value has not yet been set, or is set but expired (based on expires header), load from url:

store.fetch("beep", "http://localhost/beep").then(response => {
  console.log(response); //=> { duration: 1000, headers: {/* */}, body: { beep: 'foo' } }
  store.get("beep"); //=> { beep: 'foo' }
});

The returned Promise resolves with a response object:

• body: Object the response body
• duration: Number load time in ms
• headers: Object the parsed response headers
• key: String the key used to store the response data

options include:

• abort: Boolean abort existing (outstanding) request to same url [default: false]
• cacheControl: String default cache-control header to determine value expiry [default: "public, max-age=120, stale-if-error=180"]
• ignoreQuery: Boolean ignore query parameters of url when matching existing, oustanding requests for the same url [default: false]
• minExpiry: Number the minimum expiry (in ms) to use in cases of invalid expires [default: 60000]
• retries: Number the number of times to retry load on error [default: 2]
• rejectOnError: Boolean specify whether to reject on error or resolve with stale value [default: true]
• timeout: Number the timeout duration (in ms) before attempting retry [default: 5000]

fetchAll (keys: Array, options: Object): Promise

Batch version of fetch(). Accepts an array of [key, url, options] tuples, returning a Promise resolving to an array of results:

store
  .fetchAll([
    ["beep", "http://localhost/beep"],
    ["foo", "http://localhost/foo"]
  ])
  .then(responses => {
    store.get("beep"); //=> { beep: 'foo' }
  });

abort (key: String)

Abort outstanding load operations. If key is omitted, all operations will be aborted:

store.fetch("beep", "http://localhost/beep").then(response => {
  // Will never be called
});
store.abort("beep");