Accessing file attachments using the full API

[Matt Parizeau]

Q:

How can I access file attachment data using the full API?

A:

Here is some sample code which show how to do this:

const doc = await instance.docViewer.getDocument().getPDFDoc();
const files = await PDFNet.NameTree.find(doc, "EmbeddedFiles");
if (await files.isValid()) {
  // Traverse the list of embedded files.
  const i = await files.getIteratorBegin();
  for (var counter = 0; await i.hasNext(); await i.next(), ++counter) {
    const entry_name = await i.key().then(key => key.getAsPDFText());
    console.log("Part: " + entry_name);
    const file_spec = await PDFNet.FileSpec.createFromObj(await i.value());
    const stm = await file_spec.getFileData();
    console.log(stm);

    const filterReader = await PDFNet.FilterReader.create(stm);
    const dataArray = [];
    const chunkLength = 1024;
    let retrievedLength = chunkLength;
    while (chunkLength === retrievedLength) {
      const bufferSubArray = await filterReader.read(chunkLength);
      retrievedLength = bufferSubArray.length;
      dataArray.push(bufferSubArray);
    }
    const bufferFinal = new Uint8Array(dataArray.length * chunkLength + retrievedLength);
    for (let i = 0; i < dataArray.length; i++) {
      const offset = i * chunkLength;
      const currentArr = dataArray[i];
      bufferFinal.set(currentArr, offset);
    }
    // example function from our sample which downloads the attachment
    // you could also turn bufferFinal into a blob and open in WebViewer
    window.saveBufferAsPDFDoc(bufferFinal, 'attachment.pdf');
  }
}