Do we want generic or detailed delta messages?

[enikao]

For updating property values, we could either have one message propertyValueChanged(property, newValue?, oldValue?) or have propertyAdded(property, newValue), propertyChanged(property, newValue, oldValue) and propertyRemoved(property, oldValue). Similar for other actions.

Even more generic: featureChanged(feature, oldValue, newValue)

Options for links:

Generic:
changeChild(oldLink?, newLink?, oldParent?, newParent?, oldIndex?, newIndex, child)

Detailed:
addChild(link, newChild, index)
removeChild(link, oldChild | index)
moveChild(link, child, newIndex)
moveChild(oldLink, newLink, oldParent, newParent, oldIndex, newIndex, child)

Option A: generic

Pro:

• Slightly easier to implement event handlers with few methods
• More similar to bulk API

Con:
changeChild() has lots of optional parameters in different combinations, need to be figured out in every client

Option B: detailed

Pro:

• Easier to interpret events
• Might have "duplicate" events removeChild/addChild anyways, so always need to process detailed events

Con:

• Slightly easier to (erroneously) send Remove + Add instead of change

Decision: Option B