Allow importing multiple files for annotation

[tecoholic]

NER Annotator works with only one text file at a time. But any serious project will have multiple files for annotations. It would be useful either

• allow loading multiple files at the same time or
• provide a way to load the next file at the completion of one file

This was all the tags can be exported as a single JSON.

Note

Since the tech is browser based - memory considerations have to be kept in mind

[alvi-khan]

#72 added the option to load the next file, but I can't think of a way to export the annotations of multiple files as a single JSON. Regardless of how we solve it, the data from all of the files would have to be on memory at some point of time, at least so we can combine them.

If we disregard the memory requirements, the simple solution is to store the data from older files. Local storage seems to have a limit of 5MB. Session storage has no limit but data can't be stored across sessions.

If none of these are feasible then I think users will have to use something like the Python script given in #81. But that is bound to lead to repetitive inquiries about this feature.

@tecoholic Opinions on this?

[tecoholic]

@alvi-khan As you have explained, I see no solution for this feature to be implemented smoothly for both web and desktop the same way.

For desktop, we could leverage Rust part of the Tauri app and write some temporary files (say a project file) and read them back on next start, thus making it available across sessions. But this requires working with Rust a bit.

For web, this SO question seems to suggest that IndexedDB instead of Local or Session Storage seems to be a better option for large amount of data. Maybe we can implement IndexedDB based solution and it might end up working for both wen and desktop?

[alvi-khan]

IndexedDB seems like a viable solution. Will look into this.