Load PDFs

Use core.load() for PDFs from URLs or local files, including password-protected documents. For URLs, Core can also negotiate HTTP Range automatically.

TIP

Your UI chooses the source and presents progress or errors; Core owns the loading task and document lifecycle.

Load a URL

await core.load({
  url: '/documents/review.pdf',
  range: 'auto'
})

range: 'auto' probes HTTP Range support and downloads large PDFs in byte chunks when possible. It falls back to a full request only when the server confirms that ranges are unsupported—not for ordinary network failures.

Load a local file

const file = fileInput.files?.[0]
if (file) {
  await core.load({ data: new Uint8Array(await file.arrayBuffer()) })
}

Core does not own the file picker. The bytes are released when the document is replaced or the instance is destroyed.

Send headers and credentials

await core.load({
  url: '/api/documents/42.pdf',
  range: 'auto',
  headers: { Authorization: `Bearer ${token}` },
  credentials: 'include'
})

Do not copy source URLs, authorization headers, or PDF contents into visible error messages or telemetry.

Show loading progress

const stopProgress = core.viewer.subscribe(event => {
  if (event.type === 'loadProgress') {
    updateProgress(event.progress.percentage, event.progress.phase)
  }
})

The phase is probing, downloading, or parsing. When the total is unknown, percentage is null; a Range-backed document can become ready before every byte has arrived. Call stopProgress() during the same unmount cleanup that destroys core.

Ask for a password

const stopPassword = core.viewer.subscribe(event => {
  if (event.type !== 'passwordRequired') return
  openPasswordDialog({
    reason: event.request.reason,
    submit: password => core.viewer.submitPassword(event.request.requestId, password),
    cancel: () => core.viewer.cancelPassword(event.request.requestId)
  })
})

After an incorrect password, update the existing dialog with the new request instead of opening another one. Core never stores the password in snapshots or errors. Call stopPassword() during unmount cleanup.

Cancel or replace a load

await core.cancelLoad()
await core.load(nextSource)

A newer load wins and stale work cannot replace it. See Error recovery to turn structured loading errors into product messages.