Module: Philiprehberger::StateMachine::GraphExport

Defined in:
lib/philiprehberger/state_machine/graph_export.rb

Overview

Generates DOT/GraphViz output for state machine visualization.

Class Method Summary collapse

Class Method Details

.to_dot(definition, name: 'StateMachine') ⇒ String

Generate a DOT-format string representing the state machine.

Parameters:

  • definition (Definition) —

    the state machine definition

  • name (String) (defaults to: 'StateMachine') —

    graph name

Returns:

  • (String) —

    DOT format string



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# File 'lib/philiprehberger/state_machine/graph_export.rb', line 12

def self.to_dot(definition, name: 'StateMachine')
  lines = []
  lines << "digraph #{name} {"
  lines << '  rankdir=LR;'
  lines << ''

  # Initial state indicator
  lines << '  __start__ [shape=point, width=0.2];'
  lines << "  __start__ -> #{definition.initial};"
  lines << ''

  # State nodes
  definition.all_states.each do |state|
    lines << "  #{state} [shape=ellipse];"
  end
  lines << ''

  # Transitions
  definition.events.each do |event_name, transitions|
    transitions.each do |t|
      Array(t.from).each do |from_state|
        guard_label = t.guard ? ' [guarded]' : ''
        lines << "  #{from_state} -> #{t.to} [label=\"#{event_name}#{guard_label}\"];"
      end
    end
  end

  # Auto-transitions
  if definition.respond_to?(:auto_transitions) && definition.auto_transitions.any?
    definition.auto_transitions.each do |at|
      Array(at.from).each do |from_state|
        lines << "  #{from_state} -> #{at.to} [label=\"auto(#{at.after}s)\", style=dashed];"
      end
    end
  end

  lines << '}'
  lines.join("\n")
end