Annotations

Getting Started

npm install @prose-reader/enhancer-annotations @prose-reader/core @prose-reader/shared rxjs

All three are peer dependencies: the enhancer runs against the reader your app creates, so it shares that reader's copies rather than bringing its own.

Blank pages and annotations

Sometimes you may end up with blank pages. Some of the scenarios that lead to a blank page are:

• Document configured to show a blank page before or after a specific page (by design)
• Document spreading on more than one page but the DOM does not cover all pages

This situation is unfortunate but sometimes by design as well. Trying to annotate a page on which it's impossible to create a CFI from (other than a root CFI) will make it impossible to derive the correct page for it later.

We provide a .candidates$ observable which you can observe to know which page is a good candidate for annotation or not. A good candidate is defined as such:

• Page from a pre-paginated document (there can be only one page anyway)
• Page with a visible DOM node (meaning you can target it with a CFI)

pre-paginated documents are by design always on one page so we don't check whether they have a visible node.

Troubleshoots

Annotation CFI is empty (root CFI)

If you get a root CFI when trying to annotate a page, it is likely because we were unable to find a node to create a CFI from. This can happen when trying to annotate a blank page. Try to filter out such pages.