Schema.string

Basic example

Let's suppose we're modelling information about a dinosaur.

(For now, we'll just store its species as a string, e.g. 'Diplodocus'.)

Creation

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

import { ActiveClass, Schema } from 'fireactive'

const dinosaurSchema = {

species: Schema.string

}

class Dinosaur extends ActiveClass(dinosaurSchema) {}

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

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

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

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

new Dinosaur({ species: 'Diplodocus', randomProp: 'Triceratops' }) // works (but randomProp gets ignored as it is not on the schema)

new Dinosaur({ species: 'Diplodocus' }) // works

new Dinosaur({ species: 'Triceratops' }) // works

Assignment

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

import { ActiveClass, Schema } from 'fireactive'

const dinosaurSchema = {

species: Schema.string

}

class Dinosaur extends ActiveClass(dinosaurSchema) {}

const dinosaur = new Dinosaur({ species: 'Diplodocus' })

dinosaur.species = 'T-Rex' // works

dinosaur.species = 7 // ActiveClassError: Dinosaur could not accept the value 7 (number) at path 'species'. The property 'species' is of the wrong type

dinosaur.species = undefined // ActiveClassError: Dinosaur could not accept the value undefined (undefined) at path 'species'. The required property 'species' is missing

dinosaur.species = null // ActiveClassError: Dinosaur could not accept the value null (object) at path 'species'. The property 'species' 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 dinosaur schema to demonstrate:

• roar should default to 'RAWR';
• name, should be an optional property;
• home, should default to 'Earth' and be an optional property.

• 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 dinosaurSchema = {

species: Schema.string,

roar: Schema.string({ default: 'RAWR' }),

name: Schema.string({ optional: true }), // or required: false,

home: Schema.string({ optional: true, default: 'Earth' })

}

class Dinosaur extends ActiveClass(dinosaurSchema) {}

const dinosaur = new Dinosaur({ species: 'Diplodocus' })

dinosaur.species // => 'Diplodocus'

dinosaur.roar // => 'RAWR'

dinosaur.name // => undefined

dinosaur.home // => 'Earth'

/* species: required and no default */

dinosaur.species = undefined // ActiveClassError: Dinosaur could not accept the value undefined (undefined) at path 'species'. The required property 'species' is missing

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

/* roar: required and has default */

dinosaur.roar = undefined

dinosaur.roar // => 'RAWR' (default kicks in when undefined)

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

/* name: optional and has no default */

dinosaur.name = undefined

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

dinosaur.name = null

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

/* home: optional and has default */

dinosaur.home = undefined

dinosaur.home // => 'Earth' (default kicks in when undefined)

dinosaur.home = null

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