Skip to main content
Version: 4.5

SimpleRecord

SimpleRecord provides a simple immutable interface to store values that have defaults. When constructed it distinguishes between actually set values and ones only provided by defaults. This is useful to produce accurate merging algorithms when dealing with partial data definitions.

import { SimpleRecord } from 'rest-hooks';
export default class Article extends SimpleRecord {  readonly id: number | undefined = undefined;  readonly title: string = '';  readonly content: string = '';  readonly author: number | null = null;  readonly tags: string[] = [];}
import { SimpleRecord } from 'rest-hooks';
export default class Article extends SimpleRecord {  id = undefined;  title = '';  content = '';  author = null;  tags = [];}

Factory method#

static fromJS\<T extends typeof SimpleRecord>(this: T, props: Partial\<AbstractInstanceType\<T>>): AbstractInstanceType\<T>#

This is used to create instances of the Resource you defined. Will copy over props provided to the instance in construction, among other things. Be sure to always call super.fromJS() when overriding.

const articleA = Article.fromJS({  title: 'The best library',  tags: ['Immutable'],});const articleB = Article.fromJS({  content: 'A long droning paragraph',  tags: ['React', 'TypeScript'],});

Data methods#

static merge\<T extends typeof SimpleRecord>(first: InstanceType\<T>, second: InstanceType\<T>) => InstanceType\<T>#

Takes only the defined (non-default) values of first and second and creates a new instance copying them over. Second will override values of first. Merge is shallow, so you'll need to override this to do any deep merges.

const mergedArticle = Article.merge(articleA, articleB);console.log(mergedArticle);/*{  id: undefined,  title: 'The best library',  content: 'A long droning paragraph',  author: null,  tags: ['React', 'TypeScript'],}*/

static hasDefined\<T extends typeof SimpleRecord>(instance: InstanceType\<T>, key: keyof InstanceType\<T>) => boolean#

Returns whether provided key is defined (non-default) in instance.

console.log(articleA.hasDefined('title'));/* true */console.log(articleA.hasDefined('content'));/* false */

static toObjectDefined\<T extends typeof SimpleRecord>(instance: AbstractInstanceType\<T>) => Partial\<InstanceType\<T>>#

Returns an Object with only the defined (non-default) members of instance.

console.log(mergedArticle.toObjectDefined());/*{  title: 'The best library',  content: 'A long droning paragraph',  tags: ['React', 'TypeScript'],}*/

static keysDefined\<T extends typeof SimpleRecord>(instance: InstanceType\<T>) => (keyof InstanceType\<T>)[]#

Returns an Array of all defined (non-default) keys of instance.

console.log(mergedArticle.keysDefined());/* ['title', 'content', 'tags'] */