RelationInfoUI

How work transitions with relation?

In code

When transitioning from DetailForms to ListForms or DetailForms we need to know the relation name.

In DetailForms transition is prepared in function

    open override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

The sender is the user interface view that trigger the transition.

This sender must provide the relation name by implementing the protocol RelationInfoUI

If this sender is a button (UIButton) or any UIControl then nothing to do, all is already implemented. But for a custom view, like a labrl, you must implement it.

In storyboards

On sender the relation is added using User Defined Runtimes attributes

Then a segue must be created from detail form to the destination one using storyboard reference

RelationUI code

/// Protocol to provide info on relation
public protocol RelationInfoUI {
    /// The relation name
    var relationName: String? { get }
    /// The relation format
    var relationFormat: String? { get }

    /// Relation object data.
    var relation: Any? { get }
    /// Add action to launch segue.
    var addRelationSegueAction: Bool { get }
}