Module index

Linked data validation API.

Provides validation for linked data resources, retrieval templates, and individual values against SHACL-derived shapes.

Defining Shapes

Define resource shapes with property constraints and cardinality ranges from the value module:

import { required, optional, repeatable } from '@metreeca/blue/value';
import { boolean } from '@metreeca/blue/boolean';
import { integer } from '@metreeca/blue/number';
import { string, date } from '@metreeca/blue/string';
import { resource, id } from '@metreeca/blue/resource';

const Product = resource({
  id: id(),
  name: required(string({ model: "name", minLength: 1, maxLength: 100 })),
  price: required(integer({ minInclusive: 0 })),
  available: optional(boolean()),
  tags: repeatable(string()),
  releaseDate: optional(date())
});
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Validating Resources

Validate resources using validate, pattern matching on the Relay result:

import { validate } from '@metreeca/blue';

validate(data, { shape: Product })({
  value: product => console.log(product.name),
  trace: trace => console.error(trace)
});
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Validating Projections

When the projection Template is not bonded to the shape (typically at API boundaries where shape defines the admissible surface and the projection arrives per request), pass model as a separate argument. The return value is narrowed to Instance<T> where T is inferred from model:

const model = { id: "", name: "" };       // projection requested by the caller

validate(response, { shape: Product, model })({
  value: product => console.log(product.name),   // typed as { readonly id: Reference; readonly name: string }
  trace: trace => console.error(trace)
});
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Validating Templates

Validate a retrieval template using validate with model: true:

validate(data, { shape: Product, model: true });
validate(data, { shape: Product, model: true, plain: true });
validate(data, { shape: Product, model: true, depth: 0 });
validate(data, { shape: Product, model: true, limit: 100 });
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The model option answers "are we validating a model, or validating against one?" and selects between the three modes shown above:

• omitted or false — validate value as an instance against the shape's bonded model
• a projection Template value — validate value as an instance against that explicit projection; narrows the return to Instance<T> where T is inferred from model
• true — validate value as a retrieval template (the model itself, not an instance of it)