Add support for file segments in agent node prompts

Enhanced the AgentNode to handle FileSegment and ArrayFileSegment types when constructing user prompt messages. Now, if file segments are present in the variable pool, they are included in the prompt contents using the file_manager, allowing richer prompt construction with both text and files.

api/core/workflow/nodes/agent/agent_node.py

@@ -15,7 +15,7 @@ from core.plugin.impl.plugin import PluginInstaller
 from core.provider_manager import ProviderManager
 from core.tools.entities.tool_entities import ToolParameter, ToolProviderType
 from core.tools.tool_manager import ToolManager
-from core.variables.segments import StringSegment
+from core.variables.segments import StringSegment, FileSegment, ArrayFileSegment
 from core.workflow.entities.node_entities import NodeRunResult
 from core.workflow.entities.variable_pool import VariablePool
 from core.workflow.entities.workflow_node_execution import WorkflowNodeExecutionStatus
@@ -29,6 +29,11 @@ from core.workflow.utils.variable_template_parser import VariableTemplateParser
 from extensions.ext_database import db
 from factories.agent_factory import get_plugin_agent_strategy
 from models.model import Conversation
+from core.model_runtime.entities import (
+    UserPromptMessage,
+    TextPromptMessageContent
+)
+from core.file import file_manager
 
 
 class AgentNode(ToolNode):
@@ -268,6 +273,35 @@ class AgentNode(ToolNode):
                         value["entity"] = model_schema.model_dump(mode="json")
                     else:
                         value["entity"] = None
+
+                    current_query_segment = variable_pool.get(["sys", SystemVariableKey.QUERY.value])
+                    current_files_segment = variable_pool.get(["sys", SystemVariableKey.FILES.value])
+
+                    if current_query_segment is not None:
+                        if isinstance(current_query_segment, StringSegment):
+                            current_query = current_query_segment.value
+
+                            prompt_contents: list = [TextPromptMessageContent(data=current_query)]
+
+                            files: list = []
+                            if isinstance(current_files_segment, FileSegment):
+                                files = [current_files_segment.value]
+                            elif isinstance(current_files_segment, ArrayFileSegment):
+                                files = list(current_files_segment.value)
+
+                            if files:
+                                for f in files:
+                                    try:
+                                        prompt_contents.append(
+                                            file_manager.to_prompt_message_content(
+                                                f
+                                            )
+                                        )
+                                    except Exception:
+                                        continue
+
+                            synthetic_user_prompt = UserPromptMessage(content=prompt_contents if files else current_query)
+                            history_prompt_messages.append(synthetic_user_prompt.model_dump(mode="json"))
             result[parameter_name] = value
 
         return result