pdfTrailer

Typing of the trailer dictionary, ISO 32000-2 §7.5.5 — { size, root, info?, prev?, id?, encrypt? }.

Module pdfTrailer | Source packages/front/office/pdf/src/syntax/trailer.js | Deps pdfErrors, pdfParserObj | Worker-safe yes

A thin layer over the raw trailer dictionary. It checks the required entries (/Size, /Root) and extracts the well-defined optional ones. /Encrypt is left raw (a reference is narrowed to {num, gen}, an inline dictionary is passed through). Entries this typer does not model — /XRefStm for hybrid-reference files among them — are reachable only through raw.

Resolve

const trailer = runtime.resolve('pdfTrailer');
// Returns: { typeTrailer }

API

TypedTrailer shape

{
    size:    number,                              // /Size — required
    root:    { num: number, gen: number },        // /Root — required
    info?:   { num: number, gen: number },        // /Info — only when a ref
    id?:     [Uint8Array, Uint8Array],            // /ID — pair of strings
    prev?:   number,                              // /Prev — previous xref offset
    encrypt?: { num, gen } | PdfObject,           // /Encrypt — ref or inline dict
    raw:     PdfDict                              // the original dictionary
}

Examples

Plain typing

const xref = runtime.resolve('pdfXref');
const trailer = runtime.resolve('pdfTrailer');

const { dict } = xref.parseTrailerDict(bytes, end);
const t = trailer.typeTrailer(dict);
t.size;          // 42
t.root;          // { num: 1, gen: 0 }
t.prev;          // 12345 (on an incremental update)

Detecting an encrypted file

if (t.encrypt) {
    const sec = runtime.resolve('pdfSecurity');
    // → see the crypto layer
}

Errors

See also

• pdfXref — produces the raw dictionary consumed here.
• pdfDocument — chains trailers through /Prev.
• pdfErrors