Schema.enum

Basic example

Let's suppose we're modelling a coffee order, which can either be an Americano, Latte or Cappucino.

Creation

• Run-time type checks (JS)
• Static / compilation type checks (TS)

import { ActiveClass, Schema } from 'fireactive'

const coffeeOrderSchema = {

type: Schema.enum(['Americano', 'Latte', 'Cappucino'])

}

class CoffeeOrder extends ActiveClass(coffeeOrderSchema) {}

new CoffeeOrder() // ActiveClassError: Could not construct CoffeeOrder. The required property 'type' is missing

new CoffeeOrder({}) // ActiveClassError: Could not construct CoffeeOrder. The required property 'type' is missing

new CoffeeOrder({ type: 'Herbal' }) // ActiveClassError: Could not construct CoffeeOrder. The property 'type' is of the wrong type

new CoffeeOrder({ type: null }) // ActiveClassError: Could not construct CoffeeOrder. The property 'type' is of the wrong type

new CoffeeOrder({ type: 'Americano', randomProp: 'Latte' }) // works (but randomProp gets ignored as it is not on the schema)

new CoffeeOrder({ type: 'Americano' }) // works

new CoffeeOrder({ type: 'Latte' }) // works

Assignment

• Run-time type checks (JS)
• Static / compilation type checks (TS)

import { ActiveClass, Schema } from 'fireactive'

const coffeeOrderSchema = {

type: Schema.enum(['Americano', 'Latte', 'Cappucino'])

}

class CoffeeOrder extends ActiveClass(coffeeOrderSchema) {}

const coffeeOrder = new CoffeeOrder({ type: 'Americano' })

coffeeOrder.type = 'Latte' // works

coffeeOrder.type = 'Orange juice' // ActiveClassError: CoffeeOrder could not accept the value "Orange juice" (string) at path 'type'. The property 'type' is of the wrong type

coffeeOrder.type = undefined // ActiveClassError: CoffeeOrder could not accept the value undefined (undefined) at path 'type'. The required property 'type' is missing

coffeeOrder.type = null // ActiveClassError: CoffeeOrder could not accept the value null (object) at path 'type'. The property 'type' is of the wrong type

Configuration

A schema property can have a default value, and/or be optional.

In either case, if the property has a default value and/or is optional, it does not need to be supplied when the ActiveDocument is created.

Default values are used when a field's value would otherwise be undefined.

Only optional properties can be assigned null (i.e. the deliberate ommission of a value).

Let's add some additionl properties to our coffeeOrder schema to demonstrate:

• size should default to 'regular' but also accept 'small' and 'large';
• chain, should be an optional property, but, if given, must be 'Starbucks', 'Costa' or 'Pret';
• milk, should default to 'dairy' and be an optional property which, if given, must be 'dairy', 'oat' or 'soya'.

• Runtime type checks (JS)
• Static / compile-time type checks (TS)

Assignment when	default defined	no default defined
required: true (default) or optional: false	null: throws undefined: uses default	null: throws undefined: throws
optional: true or required: false	null: uses null undefined: uses default	null: uses null undefined: uses undefined

import { ActiveClass, Schema } from 'fireactive'

const coffeeOrderSchema = {

type: Schema.enum(['Americano', 'Latte', 'Cappucino']),

size: Schema.enum(['small', 'regular', 'large'], { default: 'regular' }),

chain: Schema.enum(['Starbucks', 'Costa', 'Pret'], { optional: true }), // or required: false,

milk: Schema.enum(['dairy', 'oat', 'soya'], { optional: true, default: 'dairy' })

}

class CoffeeOrder extends ActiveClass(coffeeOrderSchema) {}

const coffeeOrder = new CoffeeOrder({ type: false })

coffeeOrder.type // => 'Americano'

coffeeOrder.size // => 'regular'

coffeeOrder.chain // => undefined

coffeeOrder.milk // => 'dairy'

/* type: required and no default */

coffeeOrder.type = undefined // ActiveClassError: CoffeeOrder could not accept the value undefined (undefined) at path 'type'. The required property 'type' is missing

coffeeOrder.type = null // ActiveClassError: CoffeeOrder could not accept the value null (object) at path 'type'. The property 'type' is of the wrong type

/* size: required and has default */

coffeeOrder.size = undefined

coffeeOrder.size // => 'regular' (default kicks in when undefined)

coffeeOrder.size = null // ActiveClassError: CoffeeOrder could not accept the value null (object) at path 'size'. The property 'size' is of the wrong type

/* chain: optional and has no default */

coffeeOrder.chain = undefined

coffeeOrder.chain // => undefined (optional, so doesn't throw, and has no default to kick in)

coffeeOrder.chain = null

coffeeOrder.chain // => null (optional, so doesn't throw and can be null)

/* milk: optional and has default */

coffeeOrder.milk = undefined

coffeeOrder.milk // => 'dairy' (default kicks in when undefined)

coffeeOrder.milk = null

coffeeOrder.milk // => null (optional, so doesn't throw and can be null)