A keyed node helps optimize cases where children are getting added, moved, removed, etc. Common examples include:

  • The user can delete items from a list.
  • The user can create new items in a list.
  • You can sort a list based on name or date or whatever.

When you use a keyed node, every child is paired with a string identifier. This makes it possible for the underlying diffing algorithm to reuse nodes more efficiently.

Keyed Nodes

node :
-> Array (Attribute msg)
-> Array { key : String, node : Svg msg }
-> Svg msg

Works just like Svg.node, but you add a unique identifier to each child node. You want this when you have a list of nodes that is changing: adding nodes, removing nodes, etc. In these cases, the unique identifiers help make the DOM modifications more efficient.