Extract and Reapply annotation

[Shivam3062]

I’m working on integrating your PDF viewer into my application and would like to implement the following functionality:

Fetching and storing annotations: I want to fetch all annotations from the viewer, store them in my database, and then reapply them when the PDF is loaded again.

Updating existing annotations: If a user modifies an annotation, I want to update the corresponding record in the database.

I’m facing two main challenges:

Since annotations don’t seem to have a unique identifier, how can I track each individual annotation after reapplying them, so updates can be applied correctly?

I’m unable to reapply all annotations across all pages in one go—currently, it only seems to work partially.

Could you please guide me on the best approach or API methods to achieve this functionality?

[stephanrauh]

@calixteman I'm using your copy-and-paste mechanism to create an API to export an import the annotations created by the editors. As far as I remember, copying and pasting only works when the ids are removed. Now @Shivam3062 needs the id for their purposes. Do you have any idea how to solve the issue?

Come to think of it - is the idea feasible at all? When saving the PDF file, the editor annotations are merged with the regular annotations, so when the user loads the PDF later, there's no editor annotation left. Is this correct?

[calixteman]

In the current state the id is lost when saving and reopening.
I can add a NM entry in the annotation dictionary, here is the definition of this entry (from the pdf specs):

(Optional; PDF 1.4) The annotation name, a text string uniquely
identifying it among all the annotations on its page.

It can be used when replying to a comment associated with the annotation. Since we're implementing commenting stuff it could make sense to add it now.
It could be generated in using: https://developer.mozilla.org/en-US/docs/Web/API/Crypto/randomUUID

What do you think ?

[stephanrauh]

So you'd add that field in pdf.js, possibly even by default? I like that idea. I'm trying to think of any annoying side-effect, but I suspect there's none.