Where to put version __v in redux state? - mongodb

Question

I have a model that is scattered all around the application. I have a redux state tree:
{
page: {
modelPart1: ...,
... : {
modelPart2: ...
}
}
I need to keep a reference to mongoDb __v in my state too. Where is the best place to place it?
I was thinking about a separate branch model_metadata that would keep the metadata about docs (_id, __v, ...).
{
model_metadata: { <------------------------ HERE
model: {
_id: id,
__v: 2
}
}
page: {
modelPart1: ...,
... : {
modelPart2: ...
}
}
Is it a valid approach or would you recommend a different one?

Answer 1

Every reducer only can access its own part of state, so when you do
combineReducers({
one,
another
});
and access state in one, it is equivalent to doing store.getState().one, and the same for another. So, you need to split the data in page property of state into two parts: actual data and metadata. Just like the object you retrieve from Mongo.
The point in having metadata and actual data being processed by the same reducer is that every time a reducer function is performed, you have everything you need about your object in state argument of that function. Splitting the data into two different reducers would make things way more complicated.
So, the new data representation in page would look like
{
model_metadata: { <------------------------ HERE
model: {
_id: id,
__v: 2
}
}
page: {
modelPart1: ...,
... : {
modelPart2: ...
}
}
while connecting to page would look like
connect(state => ({
page: state.page
})(...)