Get/select/query all withProps(), excluding enteties

[HyruleGG]

So there are many ways how I can query entities as I read in the docs, but whats about props that I created via withProps()?

I would like to do something like userSettingsStore.getValue() but only getting withProps() and exclude entities. Maybe its better to not mix them up in 1 Store? Maybe my question is a bit related to #386 but this time its not about the select operator, just about fetching only props.

Hoping somebody can help me to wrap my mind around it.

[NetanelBasal]

They are no way to choose only props. You can group them under one key and select only the key or you can select individual props.

[HyruleGG]

Problem is on that solution, the update as I find. Since the reference always changes (even if none of the nested props do), I get a change on selecting them.

      return {
        ...state,
        ...this.userSettings,
        mediaStreamConfig: { ...this.userSettings.mediaStreamConfig }
      }

Will always result in an update...even if nothing has changed. Well for that you told me I can create an own operator that can handle...idk.

userSettingsStore.pipe(select((state) => state.mediaStreamConfig))

[NetanelBasal]

This should do the work:

selectMediaConfig$ = store.select(state => state.mediaConfig);

// As long as you don't update the mediaConfig the above selector will not emit
store.update(state => {
  return {
     ...state,
      otherProp: 'new value'
   }
})

[HyruleGG]

I'm always updating the reference to state.mediaConfig because I take the state, create a copy from it and let the user changing it via a form. When the user is done and saves() it, I do the store.update(new userSettings with new mediaConfig ref). Even if the values within the mediaConfig haven't changed, the reference always does because I made that copy.

First I thought about comparing the values dynamically but since in my case its just this fixed values in this very specific case I just did it with a hard-coded comparison that I call before the the Update.

  hasMediaStreamConfigChanged(current: MediaStreamConfig, next: MediaStreamConfig): boolean {
    if (current.activeAudioDeviceId !== next.activeAudioDeviceId) return true;
    if (current.autoGainControl !== next.autoGainControl) return true;
    if (current.echoCancellation !== next.echoCancellation) return true;
    if (current.noiseSuppression !== next.noiseSuppression) return true;
    return false;
  }

Maybe I should create an operator for this that I chain after selectMediaConfig$ = store.select(state => state.mediaConfig); . Right now I have only 1 place where I update this state so doesn't really matters for now I guess.

[NetanelBasal]

You can use distinctUntilChanged with a custom comparator function that does (prev, next) => isEqual(pre, next)

[HyruleGG]

Yea I saw that. Outcome in my case the same but for sure with distinctUntilChanged() custom compare callback would fit better to the reactive approach.

Big thanks for all the answers. Maybe one day I might create a selectProps(oldState, newState, [propName1, propName2]) operator comparing by the given props or using distinctUntilChanged() under the hood.