html-json-extractor

Fast, forgiving extraction of <script type="application/json"> and <script type="application/ld+json"> blocks from an HTML string.

• No DOM parser or runtime dependencies
• Returns one result per matching script block
• Malformed JSON blocks do not break the rest

Install

npm install html-json-extractor

Usage

import {
  extractJson,
  extractJsonStrings,
  getJsonLdItems,
  getJsonLdRecords
} from 'html-json-extractor';

const html = `
  <script type="application/json">{"featureFlags":{"search":true}}</script>
  <script type="application/ld+json">{"@type":"WebSite","name":"Example"}</script>
  <script type="application/json">{"broken":</script>
  <script type="application/ld+json">[{"@type":"Person","name":"Ada"}]</script>
`;

const raw = extractJsonStrings(html);
// ['{"featureFlags":{"search":true}}', '{"@type":"WebSite","name":"Example"}', '{"broken":', '[{"@type":"Person","name":"Ada"}]']

const parsed = extractJson(html);
// [{ featureFlags: { search: true } }, { '@type': 'WebSite', name: 'Example' }, [{ '@type': 'Person', name: 'Ada' }]]

const items = parsed.flatMap(getJsonLdItems);
// [{ featureFlags: { search: true } }, { '@type': 'WebSite', name: 'Example' }, { '@type': 'Person', name: 'Ada' }]

const records = parsed.flatMap(getJsonLdRecords);
// [{ featureFlags: { search: true } }, { '@type': 'WebSite', name: 'Example' }, { '@type': 'Person', name: 'Ada' }]

API

extractJsonStrings(html: string): string[]

Returns normalized application/json and application/ld+json script contents as strings.

extractJson<T = JsonValue>(html: string): T[]

Parses the extracted strings with JSON.parse. Entries that fail to parse are skipped.

getJsonLdItems(value: unknown): unknown[]

Normalizes a single parsed entry or parsed array entry into a flat list of items.

getJsonLdRecords(value: unknown): Record<string, unknown>[]

Returns record-shaped items and follows nested @graph content.

getJsonLdItems and getJsonLdRecords remain JSON-LD-oriented helpers for structured-data use cases on top of the generic extractor.

License

MIT