traverseDescendants

fun DelegatableNode.traverseDescendants(
    key: Any?,
    block: (TraversableNode) -> TraverseDescendantsAction,
)

Conditionally executes block for each descendant with a matching key.

Note 1: For nodes that do not have the same key, it will continue to execute the block for descendants below that non-matching node (where there may be a node that matches).

Note 2: The parameter block's return value TraverseDescendantsAction will determine the next step in the traversal.

fun <T> T.traverseDescendants(block: (T) -> TraverseDescendantsAction) where T : TraversableNode

Conditionally executes block for each descendant of the same class.

Note 1: For nodes that do not have the same key, it will continue to execute the block for the descendants below that non-matching node (where there may be a node that matches).

Note 2: The parameter block's return value TraverseDescendantsAction will determine the next step in the traversal.

Code Examples

traverseDescendantsWithKeyDemo

/**
 * Simplified example of traverseDescendants with a key. For a full featured sample, look below at
 * [TraverseModifierDemo].
 */
fun traverseDescendantsWithKeyDemo() {
    val customTraversableModifierNode = CustomTraversableModifierNode()
    with(customTraversableModifierNode) {
        traverseDescendants(traverseKey) {
            if (it is CustomTraversableModifierNode) {
                it.doSomethingWithDescendant()
            }
            // [traverseDescendants()] actually has three options:
            // - ContinueTraversal
            // - SkipSubtreeAndContinueTraversal - rarely used
            // - CancelTraversal
            // They are pretty self explanatory. Usually, you just want to continue or cancel the
            // search. In some rare cases, you might want to skip the subtree but continue searching
            // the tree.
            TraverseDescendantsAction.ContinueTraversal
        }
    }
}

traverseDescendantsDemo

/**
 * Simplified example of traverseDescendants. For a full featured sample, look below at
 * [TraverseModifierDemo].
 */
fun traverseDescendantsDemo() {
    val customTraversableModifierNode = CustomTraversableModifierNode()
    with(customTraversableModifierNode) {
        traverseDescendants {
            // Because I use the existing key of the class, I can guarantee 'it' will be of the same
            // type as the class, so I can call my functions directly.
            it.doSomethingWithDescendant()
            // [traverseDescendants()] actually has three options:
            // - ContinueTraversal
            // - SkipSubtreeAndContinueTraversal - rarely used
            // - CancelTraversal
            // They are pretty self explanatory. Usually, you just want to continue or cancel the
            // search. In some rare cases, you might want to skip the subtree but continue searching
            // the tree.
            TraverseDescendantsAction.ContinueTraversal
        }
    }
}