trackable-entities-js
Base classes that track change state when properties are updated and objects are added or removed objects from collections.
Docs: https://trackableentities.github.io/trackable-entities-js
Sample application: https://github.com/TrackableEntities/trackable-entities-js-sample.git
Note: You must change the TypeScript compiler target to "es2015" in ts.config.json.
- Apps using trackable-entities can support most modern browsers (Chrome, Firefox, Safari, Edge, etc), but they will not be able to support legacy browsers (Internet Explorer).
Setup
Install trackable-entities as a runtime dependency from npm.
npm i --save trackable-entities
Usage
To track property changes on an object, create a class that extends TrackableEntity
. Then add a constructor
that returns super.proxify(this)
. For example:
productId: number; productName: string; unitPrice: number; { super; return super; }
Then set the tracking
property to true
. Modifying property values will change the trackingState
from Unchanged
to Modified
and will populate the modifiedProperties
collection with the names of properties that were changed, so that partial updates (PATCH) may be performed by an API that knows how to apply changes to a persistence store such as a database.
// Product extends TrackableEntityproduct = 1 'Bacon' 1; // Turn on change trackingproducttracking = true; // Modify a propertyproductproductName = 'Peas'; // Tracking state is set to Modified; // Name of modified properties are tracked;
There are two collections that support change tracking: TrackableSet
which extends Set<T>
, and TrackableMap
which extends Map<K, V>
. When items are added their trackingState
is set to Added
, and when items are deleted their trackingState
is set to Deleted
.
// Create a new TrackableSet of productsconst products = 1 'Bacon' 1 2 'Lettuce' 2 3 'Tomatoes' 3;const trackableProducts = <Product>...products; // Turn on change trackingproducttracking = true; // Add an entityconst addedProduct = 4 'Carrots' 4;trackableProducts; // Tracking state is set to Added; // Remove an entityconst removedProduct = 4 'Carrots' 4;trackableProducts; // Tracking state is set to Added;
Persistence
Once the tracking state of entities have been set, you can pass them to a Web API where they can be persisted to a data store. Trackable Entities has a server-side NuGet package for persisting changes to a relational data store using Entity Framework. The current version supports the full .NET Framework with EF 6, and a future version will support .NET Core and EF Core as a NetStandard library.
Roadmap
We are currently developing the full API for trackable-entities. See the project roadmap for more information.
Contributing
If you'd like to help with this project, please contact @tonysneed via email (tony@tonysneed.com) or twitter (@tonysneed).