feat: Human Input Node (#32060)

The frontend and backend implementation for the human input node.

Co-authored-by: twwu <twwu@dify.ai>
Co-authored-by: JzoNg <jzongcode@gmail.com>
Co-authored-by: yyh <92089059+lyzno1@users.noreply.github.com>
Co-authored-by: zhsama <torvalds@linux.do>

api/core/workflow/entities/__init__.py

@@ -2,10 +2,12 @@ from .agent import AgentNodeStrategyInit
 from .graph_init_params import GraphInitParams
 from .workflow_execution import WorkflowExecution
 from .workflow_node_execution import WorkflowNodeExecution
+from .workflow_start_reason import WorkflowStartReason
 
 __all__ = [
     "AgentNodeStrategyInit",
     "GraphInitParams",
     "WorkflowExecution",
     "WorkflowNodeExecution",
+    "WorkflowStartReason",
 ]

api/core/workflow/entities/graph_init_params.py

@@ -5,6 +5,16 @@ from pydantic import BaseModel, Field
 
 
 class GraphInitParams(BaseModel):
+    """GraphInitParams encapsulates the configurations and contextual information
+    that remain constant throughout a single execution of the graph engine.
+
+    A single execution is defined as follows: as long as the execution has not reached
+    its conclusion, it is considered one execution. For instance, if a workflow is suspended
+    and later resumed, it is still regarded as a single execution, not two.
+
+    For the state diagram of workflow execution, refer to `WorkflowExecutionStatus`.
+    """
+
     # init params
     tenant_id: str = Field(..., description="tenant / workspace id")
     app_id: str = Field(..., description="app id")

api/core/workflow/entities/pause_reason.py

@@ -1,8 +1,11 @@
+from collections.abc import Mapping
 from enum import StrEnum, auto
-from typing import Annotated, Literal, TypeAlias
+from typing import Annotated, Any, Literal, TypeAlias
 
 from pydantic import BaseModel, Field
 
+from core.workflow.nodes.human_input.entities import FormInput, UserAction
+
 
 class PauseReasonType(StrEnum):
     HUMAN_INPUT_REQUIRED = auto()
@@ -11,10 +14,31 @@ class PauseReasonType(StrEnum):
 
 class HumanInputRequired(BaseModel):
     TYPE: Literal[PauseReasonType.HUMAN_INPUT_REQUIRED] = PauseReasonType.HUMAN_INPUT_REQUIRED
-
     form_id: str
-    # The identifier of the human input node causing the pause.
+    form_content: str
+    inputs: list[FormInput] = Field(default_factory=list)
+    actions: list[UserAction] = Field(default_factory=list)
+    display_in_ui: bool = False
     node_id: str
+    node_title: str
+
+    # The `resolved_default_values` stores the resolved values of variable defaults. It's a mapping from
+    # `output_variable_name` to their resolved values.
+    #
+    # For example, The form contains a input with output variable name `name` and placeholder type `VARIABLE`, its
+    # selector is ["start", "name"]. While the HumanInputNode is executed, the correspond value of variable
+    # `start.name` in variable pool is `John`. Thus, the resolved value of the output variable `name` is `John`. The
+    # `resolved_default_values` is `{"name": "John"}`.
+    #
+    # Only form inputs with default value type `VARIABLE` will be resolved and stored in `resolved_default_values`.
+    resolved_default_values: Mapping[str, Any] = Field(default_factory=dict)
+
+    # The `form_token` is the token used to submit the form via UI surfaces. It corresponds to
+    # `HumanInputFormRecipient.access_token`.
+    #
+    # This field is `None` if webapp delivery is not set and not
+    # in orchestrating mode.
+    form_token: str | None = None
 
 
 class SchedulingPause(BaseModel):

api/core/workflow/entities/workflow_start_reason.py

@@ -0,0 +1,8 @@
+from enum import StrEnum
+
+
+class WorkflowStartReason(StrEnum):
+    """Reason for workflow start events across graph/queue/SSE layers."""
+
+    INITIAL = "initial"  # First start of a workflow run.
+    RESUMPTION = "resumption"  # Start triggered after resuming a paused run.