Support `allDocs(options)` or maybe `ICollectionRxOptions['pagination']`?

[msyfls123]

https://github.com/pablomaurer/RxPouch/blob/31f412a2ec4b8727b6977ef4d39afeee4c00ab8b/src/Collection.ts#L179-L190 https://github.com/pablomaurer/RxPouch/blob/31f412a2ec4b8727b6977ef4d39afeee4c00ab8b/src/Filter.ts#L27-L29

It looks like that I have to load all documents with collection type into store & filter, it's a bit horrible! May we can add such an count() method. Besides that, I want to reserve the pagination feature.

I find out a simple but tricky solution:

1. Add ICollectionRxOptions['pagination'] which represents pagination options accepted by allDocs.
2. Copy & Paste Collection.all() to Collection.allDocs(options) and replace Colletion.loadDocs source with Collection.allDocs(options), we still need to call loadDocs with first ICollectionRxOptions['pagination'] value or startsWith {} at first.
3. Pass Collection._allDocsSubject to filter, then subscribe it to Filter.filter().
4. Subscribe to ICollectionRxOptions['pagination'] and call Collection._store.setDocs(res) to update store, and then the filter.

That's it.

---

Maybe some supported pagination related keys from allDocs options:

• options.startkey & options.endkey: Get documents with IDs in a certain range (inclusive/inclusive).
• options.inclusive_end: Include documents having an ID equal to the given options.endkey. Default: true.
• options.limit: Maximum number of documents to return.
• options.skip: Number of docs to skip before returning (warning: poor performance on IndexedDB/LevelDB!).
• options.descending: Reverse the order of the output documents. Note that the order of startkey and endkey is reversed when descending:true.

[pablomaurer]

This project ist not really maintained anymore =) But feel free to create a PR or the project ^^

Or look at https://github.com/pubkey/rxdb maybe they got you covered..