update

2025-10-05 16:06:55 +08:00 · 2025-09-19 22:30:21 +05:45
parent e4344bc96e
commit b82cd20eef
9 changed files with 565 additions and 22 deletions
--- a/dag/task_manager.go
+++ b/dag/task_manager.go
@@ -311,7 +311,8 @@ func (tm *TaskManager) areDependenciesMet(nodeID string) bool {
 				logger.Field{Key: "nodeID", Value: nodeID},
 				logger.Field{Key: "dependency", Value: prevNode.ID},
 				logger.Field{Key: "stateExists", Value: exists},
-				logger.Field{Key: "stateStatus", Value: string(state.Status)})
+				logger.Field{Key: "stateStatus", Value: string(state.Status)},
+				logger.Field{Key: "taskID", Value: tm.taskID})
 			return false
 		}
 	}
@@ -706,6 +707,13 @@ func (tm *TaskManager) onNodeCompleted(nr nodeResult) {
 	if !ok {
 		return
 	}
+
+	// Handle ResetTo functionality
+	if nr.result.ResetTo != "" {
+		tm.handleResetTo(nr)
+		return
+	}
+
 	if nr.result.Error != nil || nr.status == mq.Failed {
 		if state, exists := tm.taskStates.Get(nr.nodeID); exists {
 			tm.processFinalResult(state)
@@ -1086,3 +1094,393 @@ func (tm *TaskManager) updateTaskPosition(ctx context.Context, taskID, currentNo
 	// Save the updated task
 	return tm.storage.SaveTask(ctx, task)
 }
+
+// handleResetTo handles the ResetTo functionality for resetting a task to a specific node
+func (tm *TaskManager) handleResetTo(nr nodeResult) {
+	resetTo := nr.result.ResetTo
+	nodeID := strings.Split(nr.nodeID, Delimiter)[0]
+
+	var targetNodeID string
+	var err error
+
+	if resetTo == "back" {
+		// Use GetPreviousPageNode to find the previous page node
+		var prevNode *Node
+		prevNode, err = tm.dag.GetPreviousPageNode(nodeID)
+		if err != nil {
+			tm.dag.Logger().Error("Failed to get previous page node",
+				logger.Field{Key: "currentNodeID", Value: nodeID},
+				logger.Field{Key: "error", Value: err.Error()})
+			// Send error result
+			tm.resultCh <- mq.Result{
+				Error:   fmt.Errorf("failed to reset to previous page node: %w", err),
+				Ctx:     nr.ctx,
+				TaskID:  nr.result.TaskID,
+				Topic:   nr.result.Topic,
+				Status:  mq.Failed,
+				Payload: nr.result.Payload,
+			}
+			return
+		}
+		if prevNode == nil {
+			tm.dag.Logger().Error("No previous page node found",
+				logger.Field{Key: "currentNodeID", Value: nodeID})
+			// Send error result
+			tm.resultCh <- mq.Result{
+				Error:   fmt.Errorf("no previous page node found"),
+				Ctx:     nr.ctx,
+				TaskID:  nr.result.TaskID,
+				Topic:   nr.result.Topic,
+				Status:  mq.Failed,
+				Payload: nr.result.Payload,
+			}
+			return
+		}
+		targetNodeID = prevNode.ID
+	} else {
+		// Use the specified node ID
+		targetNodeID = resetTo
+		// Validate that the target node exists
+		if _, exists := tm.dag.nodes.Get(targetNodeID); !exists {
+			tm.dag.Logger().Error("Reset target node does not exist",
+				logger.Field{Key: "targetNodeID", Value: targetNodeID})
+			// Send error result
+			tm.resultCh <- mq.Result{
+				Error:   fmt.Errorf("reset target node %s does not exist", targetNodeID),
+				Ctx:     nr.ctx,
+				TaskID:  nr.result.TaskID,
+				Topic:   nr.result.Topic,
+				Status:  mq.Failed,
+				Payload: nr.result.Payload,
+			}
+			return
+		}
+	}
+
+	if tm.dag.debug {
+		tm.dag.Logger().Info("Resetting task to node",
+			logger.Field{Key: "taskID", Value: nr.result.TaskID},
+			logger.Field{Key: "fromNode", Value: nodeID},
+			logger.Field{Key: "toNode", Value: targetNodeID},
+			logger.Field{Key: "resetTo", Value: resetTo})
+	}
+
+	// Clear task states of all nodes between current node and target node
+	// This ensures that when we reset, the workflow can proceed correctly
+	tm.clearTaskStatesInPath(nodeID, targetNodeID)
+
+	// Also clear any deferred tasks for the target node itself
+	tm.deferredTasks.ForEach(func(taskID string, tsk *task) bool {
+		if strings.Split(tsk.nodeID, Delimiter)[0] == targetNodeID {
+			tm.deferredTasks.Del(taskID)
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Cleared deferred task for target node",
+					logger.Field{Key: "nodeID", Value: targetNodeID},
+					logger.Field{Key: "taskID", Value: taskID})
+			}
+		}
+		return true
+	})
+
+	// Handle dependencies of the target node - if they exist and are not completed,
+	// we need to mark them as completed to allow the workflow to proceed
+	tm.handleTargetNodeDependencies(targetNodeID, nr)
+
+	// Get previously received data for the target node
+	var previousPayload json.RawMessage
+	if prevResult, hasResult := tm.currentNodeResult.Get(targetNodeID); hasResult {
+		previousPayload = prevResult.Payload
+		if tm.dag.debug {
+			tm.dag.Logger().Info("Using previous payload for reset",
+				logger.Field{Key: "targetNodeID", Value: targetNodeID},
+				logger.Field{Key: "payloadSize", Value: len(previousPayload)})
+		}
+	} else {
+		// If no previous data, use the current result's payload
+		previousPayload = nr.result.Payload
+		if tm.dag.debug {
+			tm.dag.Logger().Info("No previous payload found, using current payload",
+				logger.Field{Key: "targetNodeID", Value: targetNodeID})
+		}
+	}
+
+	// Reset task state for the target node
+	if state, exists := tm.taskStates.Get(targetNodeID); exists {
+		state.Status = mq.Completed // Mark as completed to satisfy dependencies
+		state.UpdatedAt = time.Now()
+		state.Result = mq.Result{
+			Status: mq.Completed,
+			Ctx:    nr.ctx,
+		}
+	} else {
+		// Create new state if it doesn't exist and mark as completed
+		newState := newTaskState(targetNodeID)
+		newState.Status = mq.Completed
+		newState.Result = mq.Result{
+			Status: mq.Completed,
+			Ctx:    nr.ctx,
+		}
+		tm.taskStates.Set(targetNodeID, newState)
+	}
+
+	// Update current node result with the reset result (clear ResetTo to avoid loops)
+	resetResult := mq.Result{
+		TaskID:  nr.result.TaskID,
+		Topic:   targetNodeID,
+		Status:  mq.Completed, // Mark as completed
+		Payload: previousPayload,
+		Ctx:     nr.ctx,
+		// ResetTo is intentionally not set to avoid infinite loops
+	}
+	tm.currentNodeResult.Set(targetNodeID, resetResult)
+
+	// Re-enqueue the task for the target node
+	tm.enqueueTask(nr.ctx, targetNodeID, nr.result.TaskID, previousPayload)
+
+	// Log the reset activity
+	tm.logActivity(nr.ctx, nr.result.TaskID, targetNodeID, "task_reset",
+		fmt.Sprintf("Task reset from %s to %s", nodeID, targetNodeID), nil)
+}
+
+// clearTaskStatesInPath clears all task states in the path from current node to target node
+// This is necessary when resetting to ensure the workflow can proceed without dependency issues
+func (tm *TaskManager) clearTaskStatesInPath(currentNodeID, targetNodeID string) {
+	// Get all nodes in the path from current to target
+	pathNodes := tm.getNodesInPath(currentNodeID, targetNodeID)
+
+	if tm.dag.debug {
+		tm.dag.Logger().Info("Clearing task states in path",
+			logger.Field{Key: "fromNode", Value: currentNodeID},
+			logger.Field{Key: "toNode", Value: targetNodeID},
+			logger.Field{Key: "pathNodeCount", Value: len(pathNodes)})
+	}
+
+	// Also clear the current node itself (ValidateInput in the example)
+	if state, exists := tm.taskStates.Get(currentNodeID); exists {
+		state.Status = mq.Pending
+		state.UpdatedAt = time.Now()
+		state.Result = mq.Result{} // Clear previous result
+		if tm.dag.debug {
+			tm.dag.Logger().Debug("Cleared task state for current node",
+				logger.Field{Key: "nodeID", Value: currentNodeID})
+		}
+	}
+	// Also clear any cached results for the current node
+	tm.currentNodeResult.Del(currentNodeID)
+	// Clear any deferred tasks for the current node
+	tm.deferredTasks.ForEach(func(taskID string, tsk *task) bool {
+		if strings.Split(tsk.nodeID, Delimiter)[0] == currentNodeID {
+			tm.deferredTasks.Del(taskID)
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Cleared deferred task for current node",
+					logger.Field{Key: "nodeID", Value: currentNodeID},
+					logger.Field{Key: "taskID", Value: taskID})
+			}
+		}
+		return true
+	})
+
+	// Clear task states for all nodes in the path
+	for _, pathNodeID := range pathNodes {
+		if state, exists := tm.taskStates.Get(pathNodeID); exists {
+			state.Status = mq.Pending
+			state.UpdatedAt = time.Now()
+			state.Result = mq.Result{} // Clear previous result
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Cleared task state for path node",
+					logger.Field{Key: "nodeID", Value: pathNodeID})
+			}
+		}
+		// Also clear any cached results for this node
+		tm.currentNodeResult.Del(pathNodeID)
+		// Clear any deferred tasks for this node
+		tm.deferredTasks.ForEach(func(taskID string, tsk *task) bool {
+			if strings.Split(tsk.nodeID, Delimiter)[0] == pathNodeID {
+				tm.deferredTasks.Del(taskID)
+				if tm.dag.debug {
+					tm.dag.Logger().Debug("Cleared deferred task for path node",
+						logger.Field{Key: "nodeID", Value: pathNodeID},
+						logger.Field{Key: "taskID", Value: taskID})
+				}
+			}
+			return true
+		})
+	}
+}
+
+// getNodesInPath returns all nodes in the path from start node to end node
+func (tm *TaskManager) getNodesInPath(startNodeID, endNodeID string) []string {
+	visited := make(map[string]bool)
+	var result []string
+
+	// Use BFS to find the path from start to end
+	queue := []string{startNodeID}
+	visited[startNodeID] = true
+	parent := make(map[string]string)
+
+	found := false
+	for len(queue) > 0 && !found {
+		currentNodeID := queue[0]
+		queue = queue[1:]
+
+		// Get all nodes that this node points to
+		if node, exists := tm.dag.nodes.Get(currentNodeID); exists {
+			for _, edge := range node.Edges {
+				if edge.Type == Simple || edge.Type == Iterator {
+					targetNodeID := edge.To.ID
+					if !visited[targetNodeID] {
+						visited[targetNodeID] = true
+						parent[targetNodeID] = currentNodeID
+						queue = append(queue, targetNodeID)
+
+						if targetNodeID == endNodeID {
+							found = true
+							break
+						}
+					}
+				}
+			}
+		}
+	}
+
+	// If we found the end node, reconstruct the path
+	if found {
+		current := endNodeID
+		for current != startNodeID {
+			result = append([]string{current}, result...)
+			if parentNode, exists := parent[current]; exists {
+				current = parentNode
+			} else {
+				break
+			}
+		}
+		result = append([]string{startNodeID}, result...)
+	}
+
+	return result
+}
+
+// getAllDownstreamNodes returns all nodes that come after the given node in the workflow
+func (tm *TaskManager) getAllDownstreamNodes(nodeID string) []string {
+	visited := make(map[string]bool)
+	var result []string
+
+	// Use BFS to find all downstream nodes
+	queue := []string{nodeID}
+	visited[nodeID] = true
+
+	for len(queue) > 0 {
+		currentNodeID := queue[0]
+		queue = queue[1:]
+
+		// Get all nodes that this node points to
+		if node, exists := tm.dag.nodes.Get(currentNodeID); exists {
+			for _, edge := range node.Edges {
+				if edge.Type == Simple || edge.Type == Iterator {
+					targetNodeID := edge.To.ID
+					if !visited[targetNodeID] {
+						visited[targetNodeID] = true
+						result = append(result, targetNodeID)
+						queue = append(queue, targetNodeID)
+					}
+				}
+			}
+		}
+	}
+
+	return result
+}
+
+// handleTargetNodeDependencies handles the dependencies of the target node during reset
+// If the target node has unmet dependencies, we mark them as completed to allow the workflow to proceed
+func (tm *TaskManager) handleTargetNodeDependencies(targetNodeID string, nr nodeResult) {
+	// Get the dependencies of the target node
+	prevNodes, err := tm.dag.GetPreviousNodes(targetNodeID)
+	if err != nil {
+		tm.dag.Logger().Error("Error getting previous nodes for target",
+			logger.Field{Key: "targetNodeID", Value: targetNodeID},
+			logger.Field{Key: "error", Value: err.Error()})
+		return
+	}
+
+	if tm.dag.debug {
+		tm.dag.Logger().Info("Checking dependencies for target node",
+			logger.Field{Key: "targetNodeID", Value: targetNodeID},
+			logger.Field{Key: "dependencyCount", Value: len(prevNodes)})
+	}
+
+	// Check each dependency and ensure it's marked as completed for reset
+	for _, prevNode := range prevNodes {
+		// Check both the pure node ID and the indexed node ID for state
+		state, exists := tm.taskStates.Get(prevNode.ID)
+		if !exists {
+			// Also check if there's a state with an index suffix
+			tm.taskStates.ForEach(func(key string, s *TaskState) bool {
+				if strings.Split(key, Delimiter)[0] == prevNode.ID {
+					state = s
+					exists = true
+					return false // Stop iteration
+				}
+				return true
+			})
+		}
+
+		if !exists {
+			// Create new state and mark as completed for reset
+			newState := newTaskState(prevNode.ID)
+			newState.Status = mq.Completed
+			newState.UpdatedAt = time.Now()
+			newState.Result = mq.Result{
+				Status: mq.Completed,
+				Ctx:    nr.ctx,
+			}
+			tm.taskStates.Set(prevNode.ID, newState)
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Created completed state for dependency node during reset",
+					logger.Field{Key: "dependencyNodeID", Value: prevNode.ID})
+			}
+		} else if state.Status != mq.Completed {
+			// Mark existing state as completed for reset
+			state.Status = mq.Completed
+			state.UpdatedAt = time.Now()
+			if state.Result.Status == "" {
+				state.Result = mq.Result{
+					Status: mq.Completed,
+					Ctx:    nr.ctx,
+				}
+			}
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Marked dependency node as completed during reset",
+					logger.Field{Key: "dependencyNodeID", Value: prevNode.ID},
+					logger.Field{Key: "previousStatus", Value: string(state.Status)})
+			}
+		} else {
+			if tm.dag.debug {
+				tm.dag.Logger().Debug("Dependency already satisfied",
+					logger.Field{Key: "dependencyNodeID", Value: prevNode.ID},
+					logger.Field{Key: "status", Value: string(state.Status)})
+			}
+		}
+
+		// Ensure cached result exists for this dependency
+		if _, hasResult := tm.currentNodeResult.Get(prevNode.ID); !hasResult {
+			tm.currentNodeResult.Set(prevNode.ID, mq.Result{
+				Status: mq.Completed,
+				Ctx:    nr.ctx,
+			})
+		}
+
+		// Clear any deferred tasks for this dependency since it's now satisfied
+		tm.deferredTasks.ForEach(func(taskID string, tsk *task) bool {
+			if strings.Split(tsk.nodeID, Delimiter)[0] == prevNode.ID {
+				tm.deferredTasks.Del(taskID)
+				if tm.dag.debug {
+					tm.dag.Logger().Debug("Cleared deferred task for satisfied dependency",
+						logger.Field{Key: "dependencyNodeID", Value: prevNode.ID},
+						logger.Field{Key: "taskID", Value: taskID})
+				}
+			}
+			return true
+		})
+	}
+}
--- a/examples/dag.go
+++ b/examples/dag.go
@@ -24,7 +24,7 @@ func subDAG() *dag.DAG {
 	return f
 }

-func main() {
+func mai2n() {
 	flow := dag.NewDAG("Sample DAG", "sample-dag", func(taskID string, result mq.Result) {
 		fmt.Printf("DAG Final result for task %s: %s\n", taskID, string(result.Payload))
 	})
--- a/examples/enhanced_dag_example.go
+++ b/examples/enhanced_dag_example.go
@@ -11,7 +11,7 @@ import (
 )

 // Enhanced DAG Example demonstrates how to use the enhanced DAG system with workflow capabilities
-func main() {
+func mai1n() {
 	fmt.Println("🚀 Starting Enhanced DAG with Workflow Engine Demo...")

 	// Create enhanced DAG configuration
--- a/examples/form.go
+++ b/examples/form.go
@@ -26,17 +26,17 @@ func main() {
 	// Add SMS workflow nodes
 	// Note: Page nodes have no timeout by default, allowing users unlimited time for form input

-	flow.AddDAGNode(dag.Page, "Login", "login", loginSubDAG(), true)
-	flow.AddNode(dag.Page, "SMS Form", "SMSForm", &SMSFormNode{})
+	// flow.AddDAGNode(dag.Page, "Login", "login", loginSubDAG(), true)
+	flow.AddNode(dag.Page, "SMS Form", "SMSForm", &SMSFormNode{}, true)
 	flow.AddNode(dag.Function, "Validate Input", "ValidateInput", &ValidateInputNode{})
 	flow.AddNode(dag.Function, "Send SMS", "SendSMS", &SendSMSNode{})
 	flow.AddNode(dag.Page, "SMS Result", "SMSResult", &SMSResultNode{})
 	flow.AddNode(dag.Page, "Error Page", "ErrorPage", &ErrorPageNode{})

 	// Define edges for SMS workflow
-	flow.AddEdge(dag.Simple, "Login to Form", "login", "SMSForm")
+	// flow.AddEdge(dag.Simple, "Login to Form", "login", "SMSForm")
 	flow.AddEdge(dag.Simple, "Form to Validation", "SMSForm", "ValidateInput")
-	flow.AddCondition("ValidateInput", map[string]string{"valid": "SendSMS", "invalid": "ErrorPage"})
+	flow.AddCondition("ValidateInput", map[string]string{"valid": "SendSMS"}) // Removed invalid -> ErrorPage since we use ResetTo
 	flow.AddCondition("SendSMS", map[string]string{"sent": "SMSResult", "failed": "ErrorPage"})

 	// Start the flow
@@ -303,12 +303,17 @@ func (s *SMSFormNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result
 	var inputData map[string]any
 	if task.Payload != nil && len(task.Payload) > 0 {
 		if err := json.Unmarshal(task.Payload, &inputData); err == nil {
-			// If we have valid input data, pass it through for validation
-			return mq.Result{Payload: task.Payload, Ctx: ctx}
+			// Check if this is validation error data (contains validation_error)
+			if _, hasValidationError := inputData["validation_error"]; hasValidationError {
+				// This is validation error data, show the form with errors
+			} else {
+				// If we have valid input data, pass it through for validation
+				return mq.Result{Payload: task.Payload, Ctx: ctx}
+			}
 		}
 	}

-	// Otherwise, show the form
+	// Show the form (either initial load or with validation errors)
 	htmlTemplate := `
 <!DOCTYPE html>
 <html>
@@ -399,12 +404,21 @@ func (s *SMSFormNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result
        <div class="info">
            <p>Send SMS messages through our secure DAG workflow</p>
        </div>
+
+        {{if validation_error}}
+        <div class="error-message" style="background: rgba(255, 100, 100, 0.2); border: 1px solid #ff6b6b; padding: 15px; border-radius: 8px; margin-bottom: 20px; color: #ffcccc;">
+            <strong>⚠️ Validation Error:</strong> {{validation_error}}
+        </div>
+        {{end}}
+
        <form method="post" action="/process?task_id={{task_id}}&next=true">
            <div class="form-group">
                <label for="phone">📞 Phone Number:</label>
                <input type="tel" id="phone" name="phone"
                       placeholder="+1234567890 or 1234567890"
-                       required>
+                       value="{{phone}}"
+                       required
+                       {{if error_field_phone}}style="border: 2px solid #ff6b6b; background: rgba(255, 100, 100, 0.1);"{{end}}>
                <div class="info" style="margin-top: 5px; font-size: 12px;">
                    Supports US format: +1234567890 or 1234567890
                </div>
@@ -416,14 +430,16 @@ func (s *SMSFormNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result
                         placeholder="Enter your message here..."
                         maxlength="160"
                         required
-                         oninput="updateCharCount()"></textarea>
-                <div class="char-count" id="charCount">0/160 characters</div>
+                         oninput="updateCharCount()"
+                         {{if error_field_message}}style="border: 2px solid #ff6b6b; background: rgba(255, 100, 100, 0.1);"{{end}}>{{message}}</textarea>
+                <div class="char-count" id="charCount">{{message_length}}/160 characters</div>
            </div>

            <div class="form-group">
                <label for="sender_name">👤 Sender Name (Optional):</label>
                <input type="text" id="sender_name" name="sender_name"
                       placeholder="Your name or organization"
+                       value="{{sender_name}}"
                       maxlength="50">
            </div>

@@ -460,9 +476,20 @@ func (s *SMSFormNode) ProcessTask(ctx context.Context, task *mq.Task) mq.Result
 </body>
 </html>`

+	messageStr, _ := inputData["message"].(string)
+	messageLength := len(messageStr)
+
 	parser := jet.NewWithMemory(jet.WithDelims("{{", "}}"))
 	rs, err := parser.ParseTemplate(htmlTemplate, map[string]any{
-		"task_id": ctx.Value("task_id"),
+		"task_id":             ctx.Value("task_id"),
+		"validation_error":    inputData["validation_error"],
+		"error_field":         inputData["error_field"],
+		"error_field_phone":   inputData["error_field"] == "phone",
+		"error_field_message": inputData["error_field"] == "message",
+		"phone":               inputData["phone"],
+		"message":             inputData["message"],
+		"message_length":      messageLength,
+		"sender_name":         inputData["sender_name"],
 	})
 	if err != nil {
 		return mq.Result{Error: err, Ctx: ctx}
@@ -501,7 +528,11 @@ func (v *ValidateInputNode) ProcessTask(ctx context.Context, task *mq.Task) mq.R
 		inputData["validation_error"] = "Phone number is required"
 		inputData["error_field"] = "phone"
 		bt, _ := json.Marshal(inputData)
-		return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
+		return mq.Result{
+			Payload: bt,
+			Ctx:     ctx,
+			ResetTo: "SMSForm", // Reset to form instead of going to error page
+		}
 	}

 	// Clean and validate phone number format
@@ -514,7 +545,11 @@ func (v *ValidateInputNode) ProcessTask(ctx context.Context, task *mq.Task) mq.R
 		inputData["validation_error"] = "Invalid phone number format. Please use US format: +1234567890 or 1234567890"
 		inputData["error_field"] = "phone"
 		bt, _ := json.Marshal(inputData)
-		return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
+		return mq.Result{
+			Payload: bt,
+			Ctx:     ctx,
+			ResetTo: "SMSForm", // Reset to form instead of going to error page
+		}
 	}

 	// Validate message
@@ -522,14 +557,22 @@ func (v *ValidateInputNode) ProcessTask(ctx context.Context, task *mq.Task) mq.R
 		inputData["validation_error"] = "Message is required"
 		inputData["error_field"] = "message"
 		bt, _ := json.Marshal(inputData)
-		return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
+		return mq.Result{
+			Payload: bt,
+			Ctx:     ctx,
+			ResetTo: "SMSForm", // Reset to form instead of going to error page
+		}
 	}

 	if len(message) > 160 {
 		inputData["validation_error"] = "Message too long. Maximum 160 characters allowed"
 		inputData["error_field"] = "message"
 		bt, _ := json.Marshal(inputData)
-		return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
+		return mq.Result{
+			Payload: bt,
+			Ctx:     ctx,
+			ResetTo: "SMSForm", // Reset to form instead of going to error page
+		}
 	}

 	// Check for potentially harmful content
@@ -540,7 +583,11 @@ func (v *ValidateInputNode) ProcessTask(ctx context.Context, task *mq.Task) mq.R
 			inputData["validation_error"] = "Message contains prohibited content"
 			inputData["error_field"] = "message"
 			bt, _ := json.Marshal(inputData)
-			return mq.Result{Payload: bt, Ctx: ctx, ConditionStatus: "invalid"}
+			return mq.Result{
+				Payload: bt,
+				Ctx:     ctx,
+				ResetTo: "SMSForm", // Reset to form instead of going to error page
+			}
 		}
 	}

--- a/examples/reset_to_example.go
+++ b/examples/reset_to_example.go
@@ -0,0 +1,97 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/oarkflow/json"
+	"github.com/oarkflow/mq"
+	"github.com/oarkflow/mq/dag"
+)
+
+// ResetToExample demonstrates the ResetTo functionality
+type ResetToExample struct {
+	dag.Operation
+}
+
+func (r *ResetToExample) Process(ctx context.Context, task *mq.Task) mq.Result {
+	payload := string(task.Payload)
+	log.Printf("Processing node %s with payload: %s", task.Topic, payload)
+
+	// Simulate some processing logic
+	if task.Topic == "step1" {
+		// For step1, we'll return a result that resets to step2
+		return mq.Result{
+			Status:  mq.Completed,
+			Payload: json.RawMessage(`{"message": "Step 1 completed, resetting to step2"}`),
+			Ctx:     ctx,
+			TaskID:  task.ID,
+			Topic:   task.Topic,
+			ResetTo: "step2", // Reset to step2
+		}
+	} else if task.Topic == "step2" {
+		// For step2, we'll return a result that resets to the previous page node
+		return mq.Result{
+			Status:  mq.Completed,
+			Payload: json.RawMessage(`{"message": "Step 2 completed, resetting to back"}`),
+			Ctx:     ctx,
+			TaskID:  task.ID,
+			Topic:   task.Topic,
+			ResetTo: "back", // Reset to previous page node
+		}
+	} else if task.Topic == "step3" {
+		// Final step
+		return mq.Result{
+			Status:  mq.Completed,
+			Payload: json.RawMessage(`{"message": "Step 3 completed - final result"}`),
+			Ctx:     ctx,
+			TaskID:  task.ID,
+			Topic:   task.Topic,
+		}
+	}
+
+	return mq.Result{
+		Status: mq.Failed,
+		Error:  fmt.Errorf("unknown step: %s", task.Topic),
+		Ctx:    ctx,
+		TaskID: task.ID,
+		Topic:  task.Topic,
+	}
+}
+
+func runResetToExample() {
+	// Create a DAG with ResetTo functionality
+	flow := dag.NewDAG("ResetTo Example", "reset-to-example", func(taskID string, result mq.Result) {
+		log.Printf("Final result for task %s: %s", taskID, string(result.Payload))
+	})
+
+	// Add nodes
+	flow.AddNode(dag.Function, "Step 1", "step1", &ResetToExample{}, true)
+	flow.AddNode(dag.Page, "Step 2", "step2", &ResetToExample{})
+	flow.AddNode(dag.Page, "Step 3", "step3", &ResetToExample{})
+
+	// Add edges
+	flow.AddEdge(dag.Simple, "Step 1 to Step 2", "step1", "step2")
+	flow.AddEdge(dag.Simple, "Step 2 to Step 3", "step2", "step3")
+
+	// Validate the DAG
+	if err := flow.Validate(); err != nil {
+		log.Fatalf("DAG validation failed: %v", err)
+	}
+
+	// Process a task
+	data := json.RawMessage(`{"initial": "data"}`)
+	log.Println("Starting DAG processing...")
+	result := flow.Process(context.Background(), data)
+
+	if result.Error != nil {
+		log.Printf("Processing failed: %v", result.Error)
+	} else {
+		log.Printf("Processing completed successfully: %s", string(result.Payload))
+	}
+}
+
+func main() {
+	runResetToExample()
+}
--- a/examples/server.go
+++ b/examples/server.go
@@ -551,7 +551,7 @@ func Logger() HandlerFunc {
 // Example
 // ----------------------------

-func main() {
+func mai3n() {
 	app := New()
 	app.Use(Recover())

--- a/examples/simple_enhanced_dag.go
+++ b/examples/simple_enhanced_dag.go
@@ -24,7 +24,7 @@ func enhancedSubDAG() *dag.DAG {
 	return f
 }

-func main() {
+func mai4n() {
 	fmt.Println("🚀 Starting Simple Enhanced DAG Demo...")

 	// Create enhanced DAG - simple configuration, just like regular DAG but with enhanced features
--- a/examples/task_recovery_example.go
+++ b/examples/task_recovery_example.go
@@ -116,7 +116,7 @@ func demonstrateTaskRecovery() {
 	log.Println("💡 In a real scenario, the recovered task would continue processing from the 'process' node")
 }

-func main() {
+func mai5n() {
 	fmt.Println("=== DAG Task Recovery Example ===")
 	demonstrateTaskRecovery()
 }
--- a/mq.go
+++ b/mq.go
@@ -45,6 +45,7 @@ type Result struct {
 	ConditionStatus string          `json:"condition_status"`
 	Ctx             context.Context `json:"-"`
 	Payload         json.RawMessage `json:"payload"`
+	ResetTo         string          `json:"reset_to,omitempty"` // Node ID to reset to, or "back" for previous page node
 	Last            bool
 }