/// <summary>
/// The item to add to the current collection.
/// Add the specified state.
/// </summary>
/// <param name="state">State.</param>
public void Add(WorkflowState <T, TContext> state)
{
Add(state.Id, state);
}
/// <summary>
/// Initializes a new instance of the <see cref="Autoflow.WorkflowEngine{T,TContext}"/> class.
/// </summary>
/// <param name="workflowDefinition"></param>
/// <param name="currentState"></param>
/// <param name="workflowContext"></param>
public WorkflowEngine(WorkflowDefinition <T, TContext> workflowDefinition,
WorkflowState <T, TContext> currentState,
TContext workflowContext)
{
Guard.ArgumentIsNotNull(workflowDefinition, nameof(workflowDefinition));
_onTransitionedEvent = new OnWorkflowTransitionedEvent <T, TContext>();
_workflowContext = workflowContext;
_workflowDefinition = workflowDefinition;
CurrentState = currentState ?? workflowDefinition.Transitions.First().FromState;
_stateMachine = new StateMachine <WorkflowState <T, TContext>, WorkflowTrigger <T> >(() => CurrentState, s => CurrentState = s);
// Get a distinct list of states with a trigger from state configuration
// "State => Trigger => TargetState
var states = workflowDefinition.Transitions.AsQueryable()
.Select(x => x.FromState)
.Distinct()
.Select(x => x)
.ToList();
// Assign triggers to states
foreach (var state in states)
{
var triggers = workflowDefinition.Transitions.AsQueryable()
.Where(config => config.FromState == state)
.Select(config => new
{
Trigger = config.TriggeredBy,
TargetState = config.ToState,
GuardCondition = config.GuardCondition,
IsReentrant = config.IsReentry
})
.ToList();
var stateConfig = _stateMachine.Configure(state);
foreach (var trig in triggers)
{
if (trig.GuardCondition == null)
{
if (trig.IsReentrant)
{
stateConfig.PermitReentry(trig.Trigger);
}
else
{
if (trig.Trigger != null)
{
stateConfig.Permit(trig?.Trigger, trig?.TargetState);
}
}
}
else
{
if (trig.Trigger != null)
{
stateConfig.PermitIf(trig?.Trigger, trig?.TargetState, ConditionalGuard(trig?.GuardCondition));
}
}
}
//actions
//var actions = workflowDefinition.States.Where();
if (state.SuperState != null)
{
stateConfig.SubstateOf(state.SuperState);
}
if (state.EntryAction != null)
{
stateConfig.OnEntry(t => ExecuteAction(t, state.EntryAction));
}
if (state.ExitAction != null)
{
stateConfig.OnExit(t => ExecuteAction(t, state.ExitAction));
}
}
// Handle exceptions
_stateMachine.OnUnhandledTrigger(OnUnhandledTrigger);
// For all the state transitions
_stateMachine.OnTransitioned(OnTransitionAction);
}
/// <summary>
/// Provides entry point to the transitions, can be used for logging
/// </summary>
/// <param name="source"></param>
/// <param name="destination"></param>
/// <param name="trigger"></param>
/// <param name="reentery"></param>
public virtual void WorkflowEngine_OnStateTransition(WorkflowState <string, T> source,
WorkflowState <string, T> destination,
WorkflowTrigger <string> trigger, bool reentery)
{
}
/// <summary>
/// Allows for the un-handled triggers to be tracked
/// </summary>
/// <param name="state"></param>
/// <param name="trigger"></param>
protected virtual void OnUnhandledTrigger(WorkflowState <T, TContext> state, WorkflowTrigger <T> trigger)
{
OnTriggerUnhandled?.Invoke(state, trigger);
}