idb-take

Take values from IDBStore or IDBIndex

idb-take is a set of functions on top of .openCursor() functionality.

Think about it as improved IndexedDB 2.0's getAll(range, limit) method, which in addition to limit argument accepts unique, offset and reverse.

Installation

npm install --save idb-take

Example

import { take, takeOne, takeRight, takeRightOne } from 'idb-take'
import { open } from 'idb-factory'
 
// let's assume you have IndexedDB database with 'books' store and `byFrequency` index
const db = await open('mydb', 1, (e) => {
  e.target.result.createObjectStore('books', { keyPath: 'id' })  
  e.target.result.objectStore('books').createIndex('byFrequency')
})
 
// query store
const store = db.transaction(['books'], 'readonly').objectStore('books')
await take(store, { gte: 'a' }) // find all keys matching `a` pattern
await take(store, null, { limit: 10, offset: 20 }) // page=3
await takeOne(store, { lt: 'z' }) // get first value
 
// query index
const index = db.transaction(['books'], 'readonly').objectStore('books').index('byFrequency')
await take(index, { lte: 3 }, { unique: true, limit: 2 })
await takeRight(index, null, { offset: 5 }) // in reverse order
await takeRightOne(index, { gte: 10 }) // get last value

API

Each function accepts 3 arguments:

• store - an instance of IDBStore or IDBIndex. It also integrates with high level libraries which support .openCursor() method (for example: treo).
• range (optional) - IDBKeyRange instance or any idb-range argument
• opts (optional) - filter options:
  • limit - limit amount or returned values
  • offset - skip values
  • reverse - get values in reverse order using prev or prevunique when open cursor.
  • unique - get only unique values using prevunique or nextunique (applicable only for IDBIndex).

take(store, [range], [opts])

Take values from store, which satisfy range criteria.

import { take } from 'idb-take'
 
await take(store, null, { limit: 20, offset: 20 })
await take(index, { gt: 10, lt: 20 })

takeOne(store, [range], [opts])

Take first value.

takeRight(store, [range], [opts])

Take values in reverse order.

takeRightOne(store, [range], [opts])

Take last value.

License

MIT