Annotation Layers Overview

PCC’s Annotation Layering functionality makes it possible to create, view and manage multiple sets of annotations for a document enabling a new world of collaborative annotating and commenting scenarios for your document review needs.

What's an "Annotation Layer"?

An annotation layer (or layer) is a collection of annotations saved in a unique file (under this definition all annotation files you currently have are layers). The layer may be modified over time as often as desired and can be modified by different users, however, only a single user can work with the file at a time.

In order to maintain layer integrity, only one user can be modifying a layer file at any given moment.

The best way to achieve this is by having each user create their own layer for editing; this is the main scenario that annotation layers are designed upon. Note that there is nothing in the PCC code that will restrict the incorrect usage of layer files, so this is an important consideration for your implementation.

Review Layers

A "Review Layer" is simply a layer that has been loaded but cannot be modified by the current user. The user may load as many layers for review as they like, and each of these layers can be made independently visible/invisible via the user interface. While the user cannot modify any of the annotations on a Review Layer, they may comment on them which makes it possible to have conversations across multiple reviewers of a document.

With this system it’s possible to have as many people working concurrently to annotate a document as desired, and these people can see all other annotation layers if they wish (the layers will be as up-to-date as the last time the file was loaded for a user).

New Annotation File Format

When adding the Annotation Layering functionality, we revamped our annotation storage mechanism to accommodate cross-layer references for commenting. For this reason, we have moved to a new JSON file format for all annotation persistence. This JSON format is based on our new ability to persist individual annotations into a JSON object.

It's important to note that once annotation layering has been turned 'on', via the viewer configuration option, that all persistence will now use the new JSON file format. This means that when an XML file is loaded for editing, saving it again will save it as a new JSON file. When both an XML and JSON file exist with the same root filename, only the JSON file will be visible to the user (it will be as if the XML file no longer exists, although it still remains as a separate file).

For more detailed information, refer to the following topics: