Object

The Object schema is used to validate the input value as an object or Map. This schema contains some useful built-in validators to validate the input value.

The following code shows how to create an Object schema:

Validasi.object({
  'name': Validasi.string(),
  'age': Validasi.number(),
});

ObjectValidator({
  'name': StringValidator(),
  'age': NumberValidator(),
});

The Object schema requires a schema parameter a map of string-validator pairs to validate the keys and values in the object.

You can also have nesting schemas in the Object schema. The following code shows how to create a nested Object schema:

Validasi.object({
  'name': Validasi.string(),
  'address': Validasi.object({
    'street': Validasi.string(),
    'city': Validasi.string(),
  }),
});

Or combine them with other schema:

Validasi.object({
  'name': Validasi.string(),
  'addresses': Validasi.array(
    Validasi.object({
      'street': Validasi.string(),
      'city': Validasi.string(),
    }),
  ),
});

INFO

The Array schema will reconstruct your input value accoring to the schema you provided. This allow you to take advantage of transformer in the schema to convert the array value into the desired format.

Validasi.object({
    'name': Validasi.string(),
    'numbers': Validasi.array(Validasi.number(transformer: NumberTransformer())),
});

Above code can takes name: string, numbers: List<String> and returning name: string, numbers: List<num>. The numbers key will be converted according to the transformer you provided.

The null Behaviour

Since Object Validator will reconstruct your input value, it will replace the value with null if the value fail to validate. This is to ensure the object length is still the same as the input value. However, for some this behaviour might confuse you. Therefore, this guide will attempt to explain when you will receive null and kinds.

When Receive null

If the input value is null and not an object, the reconstructed object will return null as well.

var schema = Validasi.object({
  'name': Validasi.string(),
  'age': Validasi.number(),
});

print(schema.tryParse(null).value); // null

When receive object but empty

If the input value is an object but empty, the reconstructed object will differs compared to receiving null. It will return an object with all keys and values set to null.

var schema = Validasi.object({
  'name': Validasi.string(),
  'age': Validasi.number(),
});

print(schema.tryParse({}).value); // {name: null, age: null}

Available Methods

The Object schema has the following methods:

extend

The extend method is used to add more keys and validators to the object schema. The following code shows how to use the extend method:

var schema = Validasi.object({
  'name': Validasi.string(),
});

schema.extend({
  'age': Validasi.number(),
});

print(schema.tryParse({'name': 'John', 'age': 20}).value); // {name: John, age: 20}

INFO

The extend method is immutable, which means it will return a new object schema with the new keys and validators added.

without

The without method is used to remove keys from the object schema. The following code shows how to use the without method:

var schema = Validasi.object({
  'name': Validasi.string(),
  'age': Validasi.number(),
});

schema.without('age');

print(schema.tryParse({'name': 'John', 'age': 20}).value); // {name: John}

INFO

The without method is immutable, which means it will return a new object schema with the keys removed.