Class PdfLoader

Document loader for PDF files.

Extraction tiers

  1. unpdf — always used as the primary extraction engine. Performs pure-JS PDF text layer extraction with no native binaries required.
  2. OCR fallback (optional) — supplied at construction time and engaged automatically when unpdf yields sparse text (< 50 chars per page on average), indicating a scanned document.
  3. Docling fallback (optional) — when provided, takes precedence over both unpdf and OCR, yielding the highest-fidelity extraction at the cost of requiring a Python runtime.

Implements

Example

const ocrLoader    = createOcrPdfLoader();   // null if tesseract.js absent
const doclingLoader = createDoclingLoader(); // null if docling absent
const pdfLoader = new PdfLoader(ocrLoader, doclingLoader);
const doc = await pdfLoader.load('/reports/q3.pdf');

Implements

Constructors

constructor

Methods

canLoad load

Properties

supportedExtensions

Constructors

constructor

Methods

canLoad

  • canLoad(source): boolean

  • Returns true when this loader is capable of handling source.

    For string sources the check is purely extension-based. For Buffer sources the loader may inspect magic bytes when relevant.

    Parameters

    • source: string | Buffer<ArrayBufferLike>

      Absolute file path or raw bytes.

    Returns boolean

load

  • load(source, options?): Promise<LoadedDocument>

  • Parses source and returns a normalised LoadedDocument.

    When source is a string the loader treats it as an absolute (or resolvable) file path and reads the file from disk. When source is a Buffer the loader parses the bytes directly and derives as much metadata as possible from the buffer content alone.

    Parameters

    • source: string | Buffer<ArrayBufferLike>

      Absolute file path OR raw document bytes.

    • Optional options: LoadOptions

      Optional hints such as a format override.

    Returns Promise<LoadedDocument>

    A promise resolving to the fully-populated LoadedDocument.

    Throws

    When the file cannot be read or the format is not parsable.

Properties

Readonly supportedExtensions

supportedExtensions: string[] = ...

File extensions this loader handles, each with a leading dot.

Used by LoaderRegistry to route file paths to the correct loader.

Example

['.md', '.mdx']

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