Union
Describe a schema which is a union of multiple schemas. This is useful if you need the polymorphic behavior provided by schema.Array
or schema.Values
but for non-collection fields.
definition
: required An object mapping the definition of the nested entities found within the input arrayschemaAttribute
: required The attribute on each entity found that defines what schema, per the definition mapping, to use when normalizing. Can be a string or a function. If given a function, accepts the following arguments:value
: The input value of the entity.parent
: The parent object of the input array.key
: The key at which the input array appears on the parent object.
Instance Methods
define(definition)
: When used, thedefinition
passed in will be merged with the original definition passed to theUnion
constructor. This method tends to be useful for creating circular references in schema.
Usage
Note: If your data returns an object that you did not provide a mapping for, the original object will be returned in the result and an entity will not be created.
- TypeScript
- JavaScript
const data = { owner: { id: 1, type: 'user', name: 'Anne' } };
class User extends Entity {
readonly id: number = 0;
readonly type = 'user' as const;
readonly name: string = '';
pk() { return `${this.id}`; }
}
class Group extends Entity {
readonly id: number = 0;
readonly type = 'admin' as const;
pk() { return `${this.id}`; }
}
const unionSchema = new schema.Union(
{
user: User,
group: Group
},
'type'
);
const normalizedData = normalize(data, { owner: unionSchema });
const data = { owner: { id: 1, type: 'user', name: 'Anne' } };
class User extends Entity {
pk() { return `${this.id}`; }
}
class Group extends Entity {
pk() { return `${this.id}`; }
}
const unionSchema = new schema.Union(
{
user: User,
group: Group
},
'type'
);
const normalizedData = normalize(data, { owner: unionSchema });
Output
{
entities: {
User: { '1': { id: 1, type: 'user', name: 'Anne' } }
},
result: { owner: { id: 1, schema: 'User' } }
}