rest-delta-sync

Utility to synchronise the results of a REST get call with local storage. Uses a last modified flag to ensure only changes are synchronised. Uses pagination to keep package sizes down.

Each instance will synchronise one URL with a name-spaced local store

Installation

npm install rest-delta-sync

Usage:

let store = new DeltaSync(url: string, options)

options:

• storeProvider: must support getItem / setItem / removeItem - if nothing is provided local storgage is used.
• dbName: unique identifier for the type of data (analagous to a table name in SQL)
• batch size: how many records to pull down from the server per request
• frequency: how often should the db be synced with the server (in seconds)

Methods:

• start: - begins syncing immediately
• stop: - stops syncing after any current sync operation has completed

Properties:

• isInitalised: - an initial run of the sync has taken place (i.e. if data is empty it is because the source is empty)
• isRunning: - an active sync is taking place

Events:

• dataChangesInserts: - array of ids that have been added since last sync
• dataChangesUpdates: - array of ids that have been modified since last sync
• dataChangesDeletion: - arry of ids that have been removed since last sync

Data description:

Every record is expected to have the following server provided attributes

• id: string - is used to uniquely identify the record in the store.
• lastModified: string - date-time in ISO format when the record was last updated on the server.
• isDeleted: boolean - flag - which is the soft deletion flag on the server.

Building