Updating an object in the ngrx/store

Question

I\'m using @ngrx/store for an Angular 2 app.

My store holds a list of say, Book objects. I want to update a field in one of those objects. I also happ

Answer 1

The idea of the ngrx store is to have one and only one single place of truth, which means all the objects are immutable, and the only way to change anything is to recreate everything as a whole. Also, you are probably using the ngrx freeze (https://github.com/codewareio/ngrx-store-freeze) which means that all of the objects will be created read-only so you wont be able to change any (This is good for development if you want to completely follow the redux pattern). If you remove the part where the store freezes the object, you will be able to change it, but thats not best practice.

What I would suggest you is the following: Use the ngrx observable with async pipe to put the data (in your case books) in a dumb component which can only get input and output some event. Than, inside of the dumb component you can "edit" that object by making a copy of it, and after you are done, you can emit back the changes to the smart component which is subscribed to the store and allow it to change the state via the store (commit). This way is best because it is not very common to change the whole state for a really small change (like two way binding, when user types..).

If you follow the redux pattern, than you will be able to add history, which means the store will keep a copies of the last X state recreations, so you can get UNDO functionality, easier to debug, timeline etc

Your problem is that you are directly editing the property instead of recreating the whole state.