Base view class and Studio view template for read-only show page of an entity

[alexbudarov]

It would be great to have a base view class for cases when we need a read-only details of an entity.

Like https://marmelab.com/react-admin/ShowTutorial.html in React Admin.

For example:

• for views that only show data, no editing at all
• or for entities that are modified in the screen, but in a custom way. E.g. an entity linked to a business process:
  • We can move it to another status, change some attributes. But it is all done programmatically, and changes are saved via custom @Service beans.
  • There is no form with input fields to edit.
  • There are no OK / Cancel buttons. All changes are saved instantly.

Unexperienced devs are afraid to create such views from scratch. They are using StandardDetailView as base class, and after they get some problems such as:

• "unsaved changes" with no reason
• problems with "refreshing" changed entity in the data context (because InstanceLoader.load() calls DataContext.merge() -- which in turn has a very complex logic of merging entity state).

Read-only show page most likely needs to have read-only data context.

[mariodavid]

I can only back that up.

I’ve often seen this type of functionality needing manual implementation, and it was always challenging to get right. Typically, using a StandardDetailView (or its CUBA equivalent) led to state changes being managed under the hood through services, which often caused UI issues like inconsistencies and unexpected behavior.

With Jmix 2, even refreshing views is not as straightforward as before. In many cases, we opted for a Blank View instead of StandardDetailView to work around these limitations. However, this approach isn’t ideal either, as it lacks Jmix’s built-in scaffolding and attribute management.

In fact, in almost every company I’ve worked for, we needed some variation of this kind of view.