constraint.md

Constraint Descriptor

Interface

interface ConstraintDescriptor extends ComponentDescriptor {
	types: Array<string>;
	validator: (...args: any[]) => (value: any) => boolean;
	params?: string[];
}

Properties

• types

  • required
  • array of string

  The names of the types which this constraint can validate.

• validator

  • required
  • function

  The function should expect the same number of parameters as defined in the params property (and in the same order).
  The function needs to return a new function which expects a single param and returns a boolean indicating whether this value validates.

• params

  • optional
  • array of string

  The list of the parameters this constraint needs in order to validate.

Examples

Without parameters

{
	name: "integer",
	title: "Integer",
	types: ["number"],
	validator: function() {
		return function (value: number): boolean {
			return Number.isInteger(value);
		}
	}
}

With parameters

{
	name: "between",
	title: "Value Between",
	types: ["number"],
	params: ["min", "max"],
	validator: function (min: number, max: number) {
		return function (value: number): boolean {
			return value >= min && value <= max;
		}
	}
}