Guides

Annotation Replies

ComPDF React Native SDK provides annotation reply APIs for adding, reading, updating, and removing replies on PDF annotations. You can also set mark states and review states on annotations or annotation replies. These APIs are useful for document review, collaborative annotation workflows, feedback tracking, and approval flows.

API Overview

Annotation reply APIs are available on CPDFDocument:

addAnnotationReply(
  annotation: CPDFAnnotation,
  options: { content: string; title?: string }
): Promise<CPDFReplyAnnotation | null>;

getAnnotationReplies(
  annotation: CPDFAnnotation
): Promise<CPDFReplyAnnotation[]>;

updateAnnotationReply(
  reply: CPDFReplyAnnotation,
  options: { content: string; title?: string }
): Promise<boolean>;

removeAnnotationReply(reply: CPDFReplyAnnotation): Promise<boolean>;

removeAllAnnotationReplies(annotation: CPDFAnnotation): Promise<boolean>;

setAnnotationMarkState(
  annotation: CPDFAnnotation,
  state: CPDFAnnotationMarkState
): Promise<boolean>;

getAnnotationMarkState(
  annotation: CPDFAnnotation
): Promise<CPDFAnnotationMarkState>;

setAnnotationReviewState(
  annotation: CPDFAnnotation,
  state: CPDFAnnotationReviewState
): Promise<boolean>;

getAnnotationReviewState(
  annotation: CPDFAnnotation
): Promise<CPDFAnnotationReviewState>;

API description:

API	Description
addAnnotationReply	Adds a plain reply to an annotation
getAnnotationReplies	Gets all plain replies attached to an annotation
updateAnnotationReply	Updates the content and optional title of a plain reply
removeAnnotationReply	Removes one plain reply
removeAllAnnotationReplies	Removes all plain replies attached to an annotation
setAnnotationMarkState	Sets the mark state of an annotation or reply
getAnnotationMarkState	Gets the mark state of an annotation or reply
setAnnotationReviewState	Sets the review state of an annotation or reply
getAnnotationReviewState	Gets the review state of an annotation or reply

Reply Model

Annotation replies are represented by CPDFReplyAnnotation.

class CPDFReplyAnnotation extends CPDFAnnotation {
  modifyDate: Date | null;
}

Because CPDFReplyAnnotation extends CPDFAnnotation, it includes common annotation fields used in review workflows:

Property	Description
page	Zero-based page index
title	Reply author or title
content	Reply content
createDate	Reply creation time, if provided by the native SDK
modifyDate	Reply modification time, if provided by the native SDK
markState	Current mark state
reviewState	Current review state

When updating, removing, or setting the state of a reply, use a CPDFReplyAnnotation object returned by addAnnotationReply or getAnnotationReplies. Do not manually construct a CPDFReplyAnnotation and pass it to these APIs.

Mark States and Review States

Mark states:

enum CPDFAnnotationMarkState {
  MARKED = "marked",
  UNMARKED = "unmarked",
}

Review states:

enum CPDFAnnotationReviewState {
  ACCEPTED = "accepted",
  REJECTED = "rejected",
  CANCELLED = "cancelled",
  COMPLETED = "completed",
  NONE = "none",
  ERROR = "error",
}

Mark states and review states can be set on the parent annotation or on a reply annotation:

await document.setAnnotationMarkState(
  annotation,
  CPDFAnnotationMarkState.MARKED
);

await document.setAnnotationReviewState(
  annotation,
  CPDFAnnotationReviewState.ACCEPTED
);

Get an Annotation Object

Most reply operations start from an existing annotation. The following example gets the first annotation on page 1.

const page = document.pageAtIndex(0);
const annotations = await page.getAnnotations();

if (!annotations.length) {
  return;
}

const annotation = annotations[0];

Page indexes are zero-based.

Add a Reply

Use addAnnotationReply to add a plain reply to an annotation.

const reply = await document.addAnnotationReply(annotation, {
  content: "Please review this highlight.",
  title: "Alex",
});

if (!reply) {
  throw new Error("Add annotation reply failed.");
}

console.log("Reply content:", reply.content);

content is required. title is optional and is commonly used as the reply author name.

Read Replies

Use getAnnotationReplies to get all plain replies attached to an annotation.

const replies = await document.getAnnotationReplies(annotation);

for (const reply of replies) {
  console.log("Author:", reply.title);
  console.log("Content:", reply.content);
  console.log("Mark state:", reply.markState);
  console.log("Review state:", reply.reviewState);
}

The returned list contains plain replies only. Internal state replies used to store mark and review states are not exposed as separate reply items.

Update a Reply

Use updateAnnotationReply to update the content and optional title of an existing reply.

const replies = await document.getAnnotationReplies(annotation);

if (replies.length) {
  const success = await document.updateAnnotationReply(replies[0], {
    content: "Updated reply content.",
    title: "Alex",
  });

  if (!success) {
    throw new Error("Update annotation reply failed.");
  }
}

The reply parameter should come from getAnnotationReplies or addAnnotationReply.

Remove One Reply

Use removeAnnotationReply to remove one plain reply.

const replies = await document.getAnnotationReplies(annotation);

if (replies.length) {
  const success = await document.removeAnnotationReply(replies[0]);

  if (!success) {
    throw new Error("Remove annotation reply failed.");
  }
}

Remove All Replies

Use removeAllAnnotationReplies to remove all plain replies attached to an annotation.

const success = await document.removeAllAnnotationReplies(annotation);

if (!success) {
  throw new Error("Remove all annotation replies failed.");
}

This API removes plain replies only. Mark state and review state information is preserved.

Set Mark and Review States on a Reply

You can set the mark state or review state of a reply.

const replies = await document.getAnnotationReplies(annotation);

if (replies.length) {
  const reply = replies[0];

  await document.setAnnotationMarkState(
    reply,
    CPDFAnnotationMarkState.MARKED
  );

  await document.setAnnotationReviewState(
    reply,
    CPDFAnnotationReviewState.COMPLETED
  );
}

After setting a reply state, call getAnnotationReplies again if the UI needs the latest reply data.

Set States on the Parent Annotation

You can also set mark and review states directly on the parent annotation.

await document.setAnnotationMarkState(
  annotation,
  CPDFAnnotationMarkState.MARKED
);

await document.setAnnotationReviewState(
  annotation,
  CPDFAnnotationReviewState.ACCEPTED
);

const markState = await document.getAnnotationMarkState(annotation);
const reviewState = await document.getAnnotationReviewState(annotation);

console.log("Mark:", markState);
console.log("Review:", reviewState);

Use in CPDFReaderView

In a reader screen, call the same APIs through pdfReaderRef.current?._pdfDocument.

import {
  CPDFReaderView,
  CPDFAnnotationReviewState,
} from "@compdfkit_pdf_sdk/react_native";

async function addReplyToFirstAnnotation(reader: CPDFReaderView) {
  const document = reader._pdfDocument;
  const pageIndex = await reader.getCurrentPageIndex();
  const annotations = await document.pageAtIndex(pageIndex).getAnnotations();

  if (!annotations.length) {
    return;
  }

  const reply = await document.addAnnotationReply(annotations[0], {
    content: "Reviewed in the reader.",
    title: "Reviewer",
  });

  if (reply) {
    await document.setAnnotationReviewState(
      reply,
      CPDFAnnotationReviewState.COMPLETED
    );
  }
}

This approach is suitable for custom review panels, annotation lists, and collaboration toolbars.

Complete Example

The following example gets the first annotation on page 1 in a reader, adds a reply, sets the review state on that reply, and reads the reply list again.

import {
  CPDFReaderView,
  CPDFAnnotation,
  CPDFReplyAnnotation,
  CPDFAnnotationReviewState,
} from "@compdfkit_pdf_sdk/react_native";

async function reviewFirstAnnotation(reader: CPDFReaderView) {
  const document = reader._pdfDocument;
  const page = document.pageAtIndex(0);
  const annotations: CPDFAnnotation[] = await page.getAnnotations();

  if (!annotations.length) {
    return;
  }

  const annotation = annotations[0];

  const reply: CPDFReplyAnnotation | null =
    await document.addAnnotationReply(annotation, {
      content: "Please verify this annotation.",
      title: "Reviewer",
    });

  if (!reply) {
    throw new Error("Add annotation reply failed.");
  }

  await document.setAnnotationReviewState(
    reply,
    CPDFAnnotationReviewState.COMPLETED
  );

  const replies = await document.getAnnotationReplies(annotation);

  console.log("Reply count:", replies.length);
}

Notes

• When updating or removing a reply, use the CPDFReplyAnnotation object returned by the SDK.
• Do not rely on internal annotation identifiers in application logic. Pass SDK-returned annotation or reply objects directly when operating on annotations or replies.
• getAnnotationReplies returns plain replies only. State replies are handled internally by the SDK.
• removeAllAnnotationReplies removes plain replies and preserves mark state and review state information.
• After setting mark or review states, read the annotation or replies again if the UI needs the latest model data.
• Annotation and reply APIs use zero-based page indexes.
• To persist changes to the PDF file, save the document after completing the operations.