It s a good idea to bind the entire viewModel class to a vie

Question

It s a good idea to bind the entire viewModel class to a view instead specifics properties In some cases not all property and methods of the viewModel are used by the view

louiscad · Answer

I think it s not proper English I have trouble understanding your question

Francesco megna · Answer

Sorry the English is not my native language i edit the question now should is more clear

edwardwongtl · Answer

What do you mean by bind the entire viewModel to a view instead of specific properties

Francesco megna · Answer

For example I need a liveData User for my view and the User is in the viewModel class with other method and properties Now i can bind the entire viewModel to view and get the user or bind only the user

gildor · Answer

And what is question it s really depends on your case and about level of encapsulation that you expect Of course if View depends on own ViewModel with only required properties and methods this sounds like a better approach but sometimes it s just overkill it s just a matter of practical approach But what is embarrasses me is that you mentioned ViewModel so this is MVVM but in MVVM your view should know nothing about ViewModel your binding should know how to apply VM state to View or update VM according to View state so not sure what is your case when View has dependency on ViewModel

Francesco megna · Answer

In the official doc of data binding the entire viewModel is attached to the view so i think is not a violation of the architecture my questions is only about the performance

gildor · Answer

Could you show an example of official doc where view that have dependency on ViewModel Maybe we are talking about different things I don t think there is any measurable performance difference it s more about architecture

Francesco megna · Answer

Francesco megna · Answer

The first example of xml have the dependency of viewModel but probably I m wronging something show me the truth man sweat smile

gildor · Answer

It s big documentation page any particular examples

gildor · Answer

View doesn t have any dependency on View model in this example

gildor · Answer

It s Binding layout not a view View in this case is TextView class

gildor · Answer

Binding connects View and ViewModel using binding adapters but view know nothing about view model or even bindings library ViewModel also don t know about view

gildor · Answer

So what do you mean when talking about binding of entire viewmodel

Francesco megna · Answer

Mh so i missing something for me the dependency is lt data name viewModel type= com data viewModel gt the dependency is the type of the viewModel

Francesco megna · Answer

and with bind the entire viewModel I mean this core instead to bind specifics properties of the viewModel

Francesco megna · Answer

so what is the real dependency to avoid

gildor · Answer

No I m just talking about dependency like some class uses another class

Francesco megna · Answer

Ahh so you mean to avoid call a dependency of viewModel from the view right

gildor · Answer

As we already figure out I was confused because you called binding view but binding is not view

Francesco megna · Answer

yes man I confuse the terminology thx for your patience

gildor · Answer

So could you show some sample code that shows binding that uses entire viewmodel and properties Just to be clear and understand which options do you concider