collectype / factory/arrays/arrayRelation / arrayRelationFactory
arrayRelationFactory<
T,C>(ctx,oper): <K>(field,target) =>C
Defined in: factory/arrays/arrayRelation.ts:40
Creates a predicate filter for array relation using PredicType.array.relation.
T
The item type in the collection.
C extends Wherable<T, C>
The Wherable context type (must extend Wherable<T, C>).
C
The context (usually a collection) supporting the where method.
ArrayRelationOper
The array relation operation (e.g., ‘subsetOf’, ‘supersetOf’, etc.).
Returns a function that takes a field (of type array on T) and a target value, and applies the array relation predicate to filter the context.
<
K>(field,target):C
K extends string | number | symbol
K
unknown[]
C
// Example: Composing an array relation filter as a property, homogeneous model
import { BaseFunctions } from 'collectype';
import { arrayRelationFactory } from 'collectype';
type Person = { name: string; tags: string[] };
class PersonFunctions extends BaseFunctions<Person> {
arraySubsetOf = arrayRelationFactory<Person, this>(this, 'subsetOf');
}
// Usage:
const people: Person[] = [
{ name: 'Alice', tags: ['a', 'b'] },
{ name: 'Bob', tags: ['a', 'b', 'c'] }
];
const fn = new PersonFunctions(people);
const filtered = fn.arraySubsetOf('tags', ['a', 'b']);
// filtered contains the items where 'tags' is a subset of ['a', 'b']