Module string

Textual shape and factories.

Defines shapes and factories for validating textual values, mapping the JSON string type to XSD 1.0 string datatypes.

Factories validate constraint consistency at construction time: contradictory constraints like minLength > maxLength throw a RangeError.

¹ XSD 1.0 datatypes are referenced by RDF 1.1 and JSON-LD 1.1 as normative

² XSD 1.1 Part 2 § D.3.4 permits optional timezone indicators for gYear as a deviation from ISO 8601

³ Requires exactly 3 fractional second digits (millisecond precision) and UTC timezone (Z only); typed as xsd:dateTime rather than the more specific xsd:dateTimeStamp for compatibility with SPARQL temporal functions, which are defined over xsd:dateTime

Compatibility

Defining String Shapes

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

const value = string();                                                 // unconstrained string
const name = string({ model: "name", minLength: 1, maxLength: 100 });   // length-constrained
const code = string({ model: "ABC-1234", pattern: /^[A-Z]{3}-\d{4}$/ });// pattern-constrained
const status = string({ in: ["active", "inactive"] });                  // enumeration-constrained
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The model is a retrieval placeholder matched by JSON type alone: its value is immaterial and need not be legal for the shape's constraints, so an unspecified one defaults to the empty string regardless of any pattern.

Specialised String Factories

Predefined factories for common string formats:

import {
  text, markdown, email, iri, url, tag, date, time, instant, timestamp, duration
} from '@metreeca/blue/string';

const label = text();         // single-line plain text
const body = markdown();      // Markdown formatted text
const contact = email();      // RFC 5321 email address
const identifier = iri();     // RFC 3987 IRI reference
const link = url();           // RFC 3986 hierarchical URL
const language = tag();       // BCP 47 language tag
const birthday = date();      // ISO 8601 date (YYYY-MM-DD)
const start = time();         // ISO 8601 time (hh:mm:ss)
const created = instant();    // ISO 8601 datetime
const modified = timestamp(); // ISO 8601 timestamp (millisecond precision, UTC)
const validity = duration();  // ISO 8601 duration
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Using in Resource Shapes

import { required, optional } from '@metreeca/blue/value';
import { resource } from '@metreeca/blue/resource';
import { string, email, date } from '@metreeca/blue/string';

const Person = resource({
  name: required(string({ model: "name", minLength: 1 })),
  email: optional(email()),
  birthDate: optional(date())
});
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