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

[msyfls123]

RxPouch/src/Collection.ts

Lines 179 to 190 in 31f412a

	public async all() {
	let endkey = this._docType + '-\uffff';
	if (this._observableOptions.user) {
	let user = await this._observableOptions.user.pipe(first(user => user as any)).toPromise();
	endkey = this._docType + '-' + user + '\uffff'
	}
	let res = await this._pouchdb.allDocs({
	startkey: this._docType,
	endkey: endkey,
	include_docs: true
	});

RxPouch/src/Filter.ts

Lines 27 to 29 in 31f412a

	public _init() {
	this._docsSubject.next(this._getAllDocs());

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..