useDocumentRevisionGetter

Returns a function that reads the current document revision without re-rendering the component, for imperative checks inside event handlers and async flows, such as skipping a save when nothing has changed.

const getDocumentRevision = useDocumentRevisionGetter()

const revision = getDocumentRevision()

The function returns the same value as useDocumentRevision at the moment of the call, or undefined while no document is loaded.
Prefer useDocumentRevision when the revision is rendered or drives an effect: the getter is a one-time read.

Example

import { useRef } from 'react'
import { useDocumentRevisionGetter, useDocumentSaving } from '@sdk-pdf/react'

function useSaveToServer() {
  const getDocumentRevision = useDocumentRevisionGetter()
  const { prepareDocument } = useDocumentSaving()
  // The revision of the last successful save. Empty until then, so the first call always
  // saves.
  const savedRevisionRef = useRef<string | undefined>(undefined)

  return async () => {
    const revision = getDocumentRevision()
    if (revision === savedRevisionRef.current) return

    const buffer = await prepareDocument({ returnOriginalIfUnchanged: false })
    const response = await fetch('/api/documents', {
      method: 'PUT',
      body: buffer as BodyInit,
    })
    // A failed upload keeps the document unsaved.
    if (!response.ok) return

    // Records the revision the save started from: edits made during the upload stay
    // unsaved.
    savedRevisionRef.current = revision
  }
}

useDocumentRevisionGetter

Example

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