Hydrator Next

Next gen Class hydration library, super slim ~1Kb. Written mostly for Typescript. Works in both node and browser. While it is possible to use with plain JS it will require some pre-processor like babel with decorators support.

Only depends on reflect-metadata polyfil.

For Typescript, you need to have these two options turned on in tsconfig.json:

{
	"compilerOptions": {
		"emitDecoratorMetadata": true,
		"experimentalDecorators": true
	}
}

WARNING: API is not yet final

Requirements

Technically it should have no requirements.

Docs

Read the docs here

Installation

For yarn:

yarn add hydrator-next

For npm:

npm i hydrator-next

For browser just include the script or import it via ES6 import statement.

Some examples

Imports:

// ES6 JS/Typescript style
import { Hydrator } from 'hydrator-next';

// require

const { Hydrator } = require('hydrator-next');

Basic usage:

class Test {
	some = 1;
	property = 'a';
}

// hydrate from raw data
const obj = Hydrator.hydrate(Test, {some: 2, property: 'b'});

FieldType options (all of them are optional):

| Property | Type | Description | |----------|------|-------------| | type | string | Property type, has to be registered with Converter.registerConverter | | nested | constructor | If property is another nested class, explicitly state the class, ex. Date | | array | boolean | Is property an array, need to also provide type otherwise it will have no effect | | converter | (value: any, direction: DataDirection, type: string) => any; | custom converter function, example of usage below | | translate | string | Should this property be translated into some other field when hydrating/dehydrating, useful for mapping plain object under_score_case to camelCaseProperty | | translateDatabase | string | Same as translate however will only have effect when hydrating/dehydrating to database | | ignoreDatabase | boolean | value will be ignored when coming or going to database, which basically means field does not exist in database | | ignorePlain | boolean | value will be ignored when coming or going to plain object, which basically means field should not be hydrated while operating on raw data | | ignore | boolean | value will be ignored, won't ever be touched by Hydrator |

Advanced usage:

Converter.registerConverter('string', convertString);
Converter.registerConverter('number', convertNumber);
Converter.registerConverter('bigint', convertBigInt);

function customConverter(value: any, direction: DataDirection, type: string) {
	switch (direction) {
		case DataDirection.FromDatabase:
		case DataDirection.FromPlain:
			return '_' + value;
		case DataDirection.ToDatabase:
		case DataDirection.ToPlain:
			return value.substr(1);
	}
}

class TestClassCustom {
	@FieldType({ converter: customConverter })
	cust: any;
	
	// Forced to string upon hydration
	@FieldType({ type: 'string' })
	str: string;
	
	// Forced to number upon hydration
	@FieldType({ type: 'number' })
	num: string;

	// Forced to BigInt upon hydration
	@FieldType({ type: 'bigint' })
	bi: string;
	
	// Any data will come here
	fieldOfAnyValue: any = null;

	// Will not be changed at all upon migration
	@FieldType({ ignore: true })
	ignorethis: string = '9';
}

Hydrator.hydrate(TestClassCustom, {
	cust: 'a',
	str: 123,
	num: '999',
	bi: 123123,
	fieldOfAnyValue: new Date(),
	// field is not decorated nor present as property in class, thus will be ignored.
	willBeIgnored: 'aaa',
	ignorethis: 'nope'
})