Schema-DTS: TypeScript Shims for Schema.org and the Semantic Web
Eyas
・2 min read
schema-dts is a new library (and related tools) providing TypeScript definitions for Schema.org vocabulary in JSON-LD format. The typings are exposed as complete sets of discriminated type unions, allowing for easy completions and stricter validation.
Motivation
I noticed while Schema.org schema has had a lot of usage throughout the web, few Schema validation tools were integrated as part of a Developer's toolchain. For example, Google's Structured Data Testing Tool remains a main resource for many in validating the correctness of hand-written Schema.org schema.
Enter TypeScript, and the ease of defining JSON schema using typings. Thanks to the JSON-LD format and the recommendation of Google and other search engines to encode structured data using JSON-LD (rather than microdata and other structured data formats), there's an opportunity to make writing structured data much easier. We can tighten the write-test-debug iteration by including the Schema.org schema we are writing against in our development toolchain.
Usage
To use the typings for your project, simply add the schema-dts NPM package to your project:
npm install schema-dts
Then you can use it by importing "schema-dts".
Examples
Defining Simple Properties
import {Person} from "schema-dts";
const inventor: Person = {
"@type": "Person",
"name": "Grace Hopper",
"disambiguatingDescription": "American computer scientist",
"birthDate": "1906-12-09",
"deathDate": "1992-01-01",
"awards": [
"Presidential Medal of Freedom",
"National Medal of Technology and Innovation",
"IEEE Emanuel R. Piore Award",
]
};
Using 'Context'
JSON-LD requires a "@context" property to be set on the top-level JSON object, to describe the URIs represeting the types and properties being referenced. schema-dts provides the WithContext<T> type to facilitate this.
import {Organization, Thing, WithContext} from "schema-dts";
export function JsonLd<T extends Thing>(json: T): string {
return `<script type="application/ld+json">
${JSON.stringify(json)}
</script>`;
}
export const MY_ORG = JsonLd<Organization>({
"@context": "https://schema.org",
"@type": "Corporation",
"name": "Google LLC"
});
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