Sectioned Results with Empty Sections about realm-swift HOT 5 CLOSED

➤ PM Bot commented:

Jira ticket: RCOCOA-2295

from realm-swift.

Question: To me, an empty section would just be a section header with no rows following. Is that the case here?

It would be helpful to see a minimal example of the issue so we can see how the sections are being defined and what an 'empty' section would look like.

from realm-swift.

Question: To me, an empty section would just be a section header with no rows following. Is that the case here?

It would be helpful to see a minimal example of the issue so we can see how the sections are being defined and what an 'empty' section would look like.

It could be. For example, if you had a hierarchy of data (like a file system) and had a directory without childrens, then you would have an empty section.

The case in our app is that we want to have sections based on that "status" of an object: "Paused" and "Finished". Here are screenshots that depict it.

from realm-swift.

Allow me to think through this at kind of a high level here.

It's up to you, the developer to determine how 'sections' are derived. For example, if you have a contact list and want sections by the first letter representing each contact it would be something like this in Swift

@ObservedSectionedResults(Contact.self, sectionKeyPath: \.firstLetter)

or suppose you want to have sections representing States in the US that are stored in your database.

@ObservedSectionedResults(USState.self, sectionKeyPath: \.stateName)

In other words, the section headers are derived from the data itself. If there is no contact starting with "Z" then there's no "Z" section. If there's no state "Florida", there would be no section "Florida".

I would think the simple solution is to pre-populate your database with objects that you know will represent the headers, but with nil or empty properties and a property to indicate if it's a section header or not.

class Contact: Object {
   @Persisted var firstLetter = ""
   @Persisted var contactName = ""
   @Persisted var isHeader = false
}

let contactA = Contact()
contactA.firstLetter = "A"
contactA.isHeader = true

let contactB = Contact()
contatB.firstLetter = "B"
contactB.isHeader = true

then when the app starts, ensure all contacts that are headers are written which forces every section to have a header whether or not there's any actual rows within that header.

From there - just ensure queries exclude headers from their results.

Just a thought!

from realm-swift.

That might work. It feels forced but might be a viable workaround. I'll play with it and see how it works.

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