dify

dify/api/core/workflow/enums.py

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+from enum import StrEnum
+
+
+class NodeState(StrEnum):
+    """State of a node or edge during workflow execution."""
+
+    UNKNOWN = "unknown"
+    TAKEN = "taken"
+    SKIPPED = "skipped"
+
+
+class SystemVariableKey(StrEnum):
+    """
+    System Variables.
+    """
+
+    QUERY = "query"
+    FILES = "files"
+    CONVERSATION_ID = "conversation_id"
+    USER_ID = "user_id"
+    DIALOGUE_COUNT = "dialogue_count"
+    APP_ID = "app_id"
+    WORKFLOW_ID = "workflow_id"
+    WORKFLOW_EXECUTION_ID = "workflow_run_id"
+    TIMESTAMP = "timestamp"
+    # RAG Pipeline
+    DOCUMENT_ID = "document_id"
+    ORIGINAL_DOCUMENT_ID = "original_document_id"
+    BATCH = "batch"
+    DATASET_ID = "dataset_id"
+    DATASOURCE_TYPE = "datasource_type"
+    DATASOURCE_INFO = "datasource_info"
+    INVOKE_FROM = "invoke_from"
+
+
+class NodeType(StrEnum):
+    START = "start"
+    END = "end"
+    ANSWER = "answer"
+    LLM = "llm"
+    KNOWLEDGE_RETRIEVAL = "knowledge-retrieval"
+    KNOWLEDGE_INDEX = "knowledge-index"
+    IF_ELSE = "if-else"
+    CODE = "code"
+    TEMPLATE_TRANSFORM = "template-transform"
+    QUESTION_CLASSIFIER = "question-classifier"
+    HTTP_REQUEST = "http-request"
+    TOOL = "tool"
+    DATASOURCE = "datasource"
+    VARIABLE_AGGREGATOR = "variable-aggregator"
+    LEGACY_VARIABLE_AGGREGATOR = "variable-assigner"  # TODO: Merge this into VARIABLE_AGGREGATOR in the database.
+    LOOP = "loop"
+    LOOP_START = "loop-start"
+    LOOP_END = "loop-end"
+    ITERATION = "iteration"
+    ITERATION_START = "iteration-start"  # Fake start node for iteration.
+    PARAMETER_EXTRACTOR = "parameter-extractor"
+    VARIABLE_ASSIGNER = "assigner"
+    DOCUMENT_EXTRACTOR = "document-extractor"
+    LIST_OPERATOR = "list-operator"
+    AGENT = "agent"
+    TRIGGER_WEBHOOK = "trigger-webhook"
+    TRIGGER_SCHEDULE = "trigger-schedule"
+    TRIGGER_PLUGIN = "trigger-plugin"
+    HUMAN_INPUT = "human-input"
+
+    @property
+    def is_trigger_node(self) -> bool:
+        """Check if this node type is a trigger node."""
+        return self in [
+            NodeType.TRIGGER_WEBHOOK,
+            NodeType.TRIGGER_SCHEDULE,
+            NodeType.TRIGGER_PLUGIN,
+        ]
+
+    @property
+    def is_start_node(self) -> bool:
+        """Check if this node type can serve as a workflow entry point."""
+        return self in [
+            NodeType.START,
+            NodeType.DATASOURCE,
+            NodeType.TRIGGER_WEBHOOK,
+            NodeType.TRIGGER_SCHEDULE,
+            NodeType.TRIGGER_PLUGIN,
+        ]
+
+
+class NodeExecutionType(StrEnum):
+    """Node execution type classification."""
+
+    EXECUTABLE = "executable"  # Regular nodes that execute and produce outputs
+    RESPONSE = "response"  # Response nodes that stream outputs (Answer, End)
+    BRANCH = "branch"  # Nodes that can choose different branches (if-else, question-classifier)
+    CONTAINER = "container"  # Container nodes that manage subgraphs (iteration, loop, graph)
+    ROOT = "root"  # Nodes that can serve as execution entry points
+
+
+class ErrorStrategy(StrEnum):
+    FAIL_BRANCH = "fail-branch"
+    DEFAULT_VALUE = "default-value"
+
+
+class FailBranchSourceHandle(StrEnum):
+    FAILED = "fail-branch"
+    SUCCESS = "success-branch"
+
+
+class WorkflowType(StrEnum):
+    """
+    Workflow Type Enum for domain layer
+    """
+
+    WORKFLOW = "workflow"
+    CHAT = "chat"
+    RAG_PIPELINE = "rag-pipeline"
+
+
+class WorkflowExecutionStatus(StrEnum):
+    # State diagram for the workflw status:
+    # (@) means start, (*) means end
+    #
+    #       ┌------------------>------------------------->------------------->--------------┐
+    #       |                                                                               |
+    #       |                       ┌-----------------------<--------------------┐          |
+    #       ^                       |                                            |          |
+    #       |                       |                                            ^          |
+    #       |                       V                                            |          |
+    # ┌-----------┐        ┌-----------------------┐                       ┌-----------┐    V
+    # | Scheduled |------->|        Running        |---------------------->|   paused  |    |
+    # └-----------┘        └-----------------------┘                       └-----------┘    |
+    #       |                |       |       |    |                              |          |
+    #       |                |       |       |    |                              |          |
+    #       ^                |       |       |    V                              V          |
+    #       |                |       |       |    |                         ┌---------┐     |
+    #      (@)               |       |       |    └------------------------>| Stopped |<----┘
+    #                        |       |       |                              └---------┘
+    #                        |       |       |                                   |
+    #                        |       |       V                                   V
+    #                        |       |  ┌-----------┐                            |
+    #                        |       |  | Succeeded |------------->--------------┤
+    #                        |       |  └-----------┘                            |
+    #                        |       V                                           V
+    #                        |  +--------┐                                       |
+    #                        |  | Failed |---------------------->----------------┤
+    #                        |  └--------┘                                       |
+    #                        V                                                   V
+    #             ┌---------------------┐                                        |
+    #             | Partially Succeeded |---------------------->-----------------┘--------> (*)
+    #             └---------------------┘
+    #
+    # Mermaid diagram:
+    #
+    #     ---
+    #     title: State diagram for Workflow run state
+    #     ---
+    #     stateDiagram-v2
+    #         scheduled: Scheduled
+    #         running: Running
+    #         succeeded: Succeeded
+    #         failed: Failed
+    #         partial_succeeded: Partial Succeeded
+    #         paused: Paused
+    #         stopped: Stopped
+    #
+    #         [*] --> scheduled:
+    #         scheduled --> running: Start Execution
+    #         running --> paused: Human input required
+    #         paused --> running: human input added
+    #         paused --> stopped: User stops execution
+    #         running --> succeeded: Execution finishes without any error
+    #         running --> failed: Execution finishes with errors
+    #         running --> stopped: User stops execution
+    #         running --> partial_succeeded: some execution occurred and handled during execution
+    #
+    #         scheduled --> stopped: User stops execution
+    #
+    #         succeeded --> [*]
+    #         failed --> [*]
+    #         partial_succeeded --> [*]
+    #         stopped --> [*]
+
+    # `SCHEDULED` means that the workflow is scheduled to run, but has not
+    # started running yet. (maybe due to possible worker saturation.)
+    #
+    # This enum value is currently unused.
+    SCHEDULED = "scheduled"
+
+    # `RUNNING` means the workflow is exeuting.
+    RUNNING = "running"
+
+    # `SUCCEEDED` means the execution of workflow succeed without any error.
+    SUCCEEDED = "succeeded"
+
+    # `FAILED` means the execution of workflow failed without some errors.
+    FAILED = "failed"
+
+    # `STOPPED` means the execution of workflow was stopped, either manually
+    # by the user, or automatically by the Dify application (E.G. the moderation
+    # mechanism.)
+    STOPPED = "stopped"
+
+    # `PARTIAL_SUCCEEDED` indicates that some errors occurred during the workflow
+    # execution, but they were successfully handled (e.g., by using an error
+    # strategy such as "fail branch" or "default value").
+    PARTIAL_SUCCEEDED = "partial-succeeded"
+
+    # `PAUSED` indicates that the workflow execution is temporarily paused
+    # (e.g., awaiting human input) and is expected to resume later.
+    PAUSED = "paused"
+
+    def is_ended(self) -> bool:
+        return self in _END_STATE
+
+
+_END_STATE = frozenset(
+    [
+        WorkflowExecutionStatus.SUCCEEDED,
+        WorkflowExecutionStatus.FAILED,
+        WorkflowExecutionStatus.PARTIAL_SUCCEEDED,
+        WorkflowExecutionStatus.STOPPED,
+    ]
+)
+
+
+class WorkflowNodeExecutionMetadataKey(StrEnum):
+    """
+    Node Run Metadata Key.
+    """
+
+    TOTAL_TOKENS = "total_tokens"
+    TOTAL_PRICE = "total_price"
+    CURRENCY = "currency"
+    TOOL_INFO = "tool_info"
+    AGENT_LOG = "agent_log"
+    TRIGGER_INFO = "trigger_info"
+    ITERATION_ID = "iteration_id"
+    ITERATION_INDEX = "iteration_index"
+    LOOP_ID = "loop_id"
+    LOOP_INDEX = "loop_index"
+    PARALLEL_ID = "parallel_id"
+    PARALLEL_START_NODE_ID = "parallel_start_node_id"
+    PARENT_PARALLEL_ID = "parent_parallel_id"
+    PARENT_PARALLEL_START_NODE_ID = "parent_parallel_start_node_id"
+    PARALLEL_MODE_RUN_ID = "parallel_mode_run_id"
+    ITERATION_DURATION_MAP = "iteration_duration_map"  # single iteration duration if iteration node runs
+    LOOP_DURATION_MAP = "loop_duration_map"  # single loop duration if loop node runs
+    ERROR_STRATEGY = "error_strategy"  # node in continue on error mode return the field
+    LOOP_VARIABLE_MAP = "loop_variable_map"  # single loop variable output
+    DATASOURCE_INFO = "datasource_info"
+
+
+class WorkflowNodeExecutionStatus(StrEnum):
+    PENDING = "pending"  # Node is scheduled but not yet executing
+    RUNNING = "running"
+    SUCCEEDED = "succeeded"
+    FAILED = "failed"
+    EXCEPTION = "exception"
+    STOPPED = "stopped"
+    PAUSED = "paused"
+
+    # Legacy statuses - kept for backward compatibility
+    RETRY = "retry"  # Legacy: replaced by retry mechanism in error handling