refactor(api): Separate SegmentType for Integer/Float to Enable Pydantic Serialization (#22025)

refactor(api): Separate SegmentType for Integer/Float to Enable Pydantic Serialization (#22025)

This PR addresses serialization issues in the VariablePool model by separating the `value_type` tags for `IntegerSegment`/`FloatSegment` and `IntegerVariable`/`FloatVariable`. Previously, both Integer and Float types shared the same `SegmentType.NUMBER` tag, causing conflicts during serialization.

Key changes:
- Introduce distinct `value_type` tags for Integer and Float segments/variables
- Add `VariableUnion` and `SegmentUnion` types for proper type discrimination
- Leverage Pydantic's discriminated union feature for seamless serialization/deserialization
- Enable accurate serialization of data structures containing these types

Closes #22024.

api/core/app/apps/workflow/app_runner.py

@@ -11,7 +11,7 @@ from core.app.entities.app_invoke_entities import (
 )
 from core.workflow.callbacks import WorkflowCallback, WorkflowLoggingCallback
 from core.workflow.entities.variable_pool import VariablePool
-from core.workflow.enums import SystemVariableKey
+from core.workflow.system_variable import SystemVariable
 from core.workflow.variable_loader import VariableLoader
 from core.workflow.workflow_entry import WorkflowEntry
 from extensions.ext_database import db
@@ -95,13 +95,14 @@ class WorkflowAppRunner(WorkflowBasedAppRunner):
             files = self.application_generate_entity.files
 
             # Create a variable pool.
-            system_inputs = {
-                SystemVariableKey.FILES: files,
-                SystemVariableKey.USER_ID: user_id,
-                SystemVariableKey.APP_ID: app_config.app_id,
-                SystemVariableKey.WORKFLOW_ID: app_config.workflow_id,
-                SystemVariableKey.WORKFLOW_EXECUTION_ID: self.application_generate_entity.workflow_execution_id,
-            }
+
+            system_inputs = SystemVariable(
+                files=files,
+                user_id=user_id,
+                app_id=app_config.app_id,
+                workflow_id=app_config.workflow_id,
+                workflow_execution_id=self.application_generate_entity.workflow_execution_id,
+            )
 
             variable_pool = VariablePool(
                 system_variables=system_inputs,

api/core/app/apps/workflow/generate_task_pipeline.py

@@ -54,10 +54,10 @@ from core.app.task_pipeline.based_generate_task_pipeline import BasedGenerateTas
 from core.base.tts import AppGeneratorTTSPublisher, AudioTrunk
 from core.ops.ops_trace_manager import TraceQueueManager
 from core.workflow.entities.workflow_execution import WorkflowExecution, WorkflowExecutionStatus, WorkflowType
-from core.workflow.enums import SystemVariableKey
 from core.workflow.repositories.draft_variable_repository import DraftVariableSaverFactory
 from core.workflow.repositories.workflow_execution_repository import WorkflowExecutionRepository
 from core.workflow.repositories.workflow_node_execution_repository import WorkflowNodeExecutionRepository
+from core.workflow.system_variable import SystemVariable
 from core.workflow.workflow_cycle_manager import CycleManagerWorkflowInfo, WorkflowCycleManager
 from extensions.ext_database import db
 from models.account import Account
@@ -107,13 +107,13 @@ class WorkflowAppGenerateTaskPipeline:
 
         self._workflow_cycle_manager = WorkflowCycleManager(
             application_generate_entity=application_generate_entity,
-            workflow_system_variables={
-                SystemVariableKey.FILES: application_generate_entity.files,
-                SystemVariableKey.USER_ID: user_session_id,
-                SystemVariableKey.APP_ID: application_generate_entity.app_config.app_id,
-                SystemVariableKey.WORKFLOW_ID: workflow.id,
-                SystemVariableKey.WORKFLOW_EXECUTION_ID: application_generate_entity.workflow_execution_id,
-            },
+            workflow_system_variables=SystemVariable(
+                files=application_generate_entity.files,
+                user_id=user_session_id,
+                app_id=application_generate_entity.app_config.app_id,
+                workflow_id=workflow.id,
+                workflow_execution_id=application_generate_entity.workflow_execution_id,
+            ),
             workflow_info=CycleManagerWorkflowInfo(
                 workflow_id=workflow.id,
                 workflow_type=WorkflowType(workflow.type),