next-node-rules.md

Next node rules

The next_node method takes a block that should return the next node (question or outcome) to send the user to. The relevant node key must be returned via the question or outcome method.

next_node do |response|
  if response == 'green'
    question :green? # Go to the :green? question node
  else
    outcome :red # Go to the :red outcome node
  end
end

Errors

Multiple calls to next_node are not allowed

Occurs if next_node is called more than once within a single question block.

# For example
next_node do
  outcome :red
end
next_node do
  question :green?
end

ArgumentError: You must specify a block

Occurs if next_node is called without a block.

# For example
next_node

Next node undefined

Occurs if the next_node block returns something "falsey" (e.g. nil).

# For example
next_node do
  nil
end

Next node not returned via question or outcome method

Occurs if the next_node block returns something which was not returned by a call to #question or #outcome.

# For example
next_node do
  :green?
end

Node "node-name" does not exist

Occurs if the next_node blocks returns a value that isn't defined as a question or outcome node.

# For example
next_node do
  outcome :red
end
outcome :blue