Function createEmbeddedFileStream

src/attachments/file-spec.ts:245–279

(
  data: Uint8Array,
  filename: string,
  options: AddAttachmentOptions = {},
)

 * @returns A PdfStream for the embedded file
 */
export function createEmbeddedFileStream(
  data: Uint8Array,
  filename: string,
  options: AddAttachmentOptions = {},
): PdfStream {
  const now = new Date();
  const mimeType = options.mimeType ?? getMimeType(filename);

  // Build params dictionary
  const paramsEntries: Array<[string, PdfObject]> = [["Size", PdfNumber.of(data.length)]];

  const createdAt = options.createdAt ?? now;
  paramsEntries.push(["CreationDate", PdfString.fromString(formatPdfDate(createdAt))]);

  const modifiedAt = options.modifiedAt ?? now;
  paramsEntries.push(["ModDate", PdfString.fromString(formatPdfDate(modifiedAt))]);

  const params = new PdfDict(paramsEntries);

  // Build stream dictionary entries
  const streamEntries: Array<[string, PdfObject]> = [
    ["Type", PdfName.of("EmbeddedFile")],
    ["Params", params],
  ];

  // Add MIME type if known

  if (mimeType) {
    // Encode MIME type as PDF name (replace / with #2F)
    const encodedMime = mimeType.replaceAll("/", "#2F").replaceAll(" ", "#20");
    streamEntries.push(["Subtype", PdfName.of(encodedMime)]);
  }

  return new PdfStream(streamEntries, data);
}

/**
 * Create a FileSpec dictionary for an embedded file.