refactor(core): decouple LLMNode prompt handling

Moved prompt handling functions out of the `LLMNode` class to improve modularity and separation of concerns. This refactor allows better reuse and testing of prompt-related functions. Adjusted existing logic to fetch queries and handle context and memory configurations more effectively. Updated tests to align with the new structure and ensure continued functionality.

api/core/workflow/nodes/llm/node.py

@@ -38,7 +38,6 @@ from core.variables import (
     ObjectSegment,
     StringSegment,
 )
-from core.workflow.constants import SYSTEM_VARIABLE_NODE_ID
 from core.workflow.entities.node_entities import NodeRunMetadataKey, NodeRunResult
 from core.workflow.entities.variable_entities import VariableSelector
 from core.workflow.entities.variable_pool import VariablePool
@@ -135,10 +134,7 @@ class LLMNode(BaseNode[LLMNodeData]):
 
             # fetch prompt messages
             if self.node_data.memory:
-                query = self.graph_runtime_state.variable_pool.get((SYSTEM_VARIABLE_NODE_ID, SystemVariableKey.QUERY))
-                if not query:
-                    raise VariableNotFoundError("Query not found")
-                query = query.text
+                query = self.node_data.memory.query_prompt_template
             else:
                 query = None
 
@@ -152,6 +148,8 @@ class LLMNode(BaseNode[LLMNodeData]):
                 memory_config=self.node_data.memory,
                 vision_enabled=self.node_data.vision.enabled,
                 vision_detail=self.node_data.vision.configs.detail,
+                variable_pool=self.graph_runtime_state.variable_pool,
+                jinja2_variables=self.node_data.prompt_config.jinja2_variables,
             )
 
             process_data = {
@@ -550,15 +548,25 @@ class LLMNode(BaseNode[LLMNodeData]):
         memory_config: MemoryConfig | None = None,
         vision_enabled: bool = False,
         vision_detail: ImagePromptMessageContent.DETAIL,
+        variable_pool: VariablePool,
+        jinja2_variables: Sequence[VariableSelector],
     ) -> tuple[Sequence[PromptMessage], Optional[Sequence[str]]]:
         prompt_messages = []
 
         if isinstance(prompt_template, list):
             # For chat model
-            prompt_messages.extend(self._handle_list_messages(messages=prompt_template, context=context))
+            prompt_messages.extend(
+                _handle_list_messages(
+                    messages=prompt_template,
+                    context=context,
+                    jinja2_variables=jinja2_variables,
+                    variable_pool=variable_pool,
+                    vision_detail_config=vision_detail,
+                )
+            )
 
             # Get memory messages for chat mode
-            memory_messages = self._handle_memory_chat_mode(
+            memory_messages = _handle_memory_chat_mode(
                 memory=memory,
                 memory_config=memory_config,
                 model_config=model_config,
@@ -568,14 +576,34 @@ class LLMNode(BaseNode[LLMNodeData]):
 
             # Add current query to the prompt messages
             if user_query:
-                prompt_messages.append(UserPromptMessage(content=[TextPromptMessageContent(data=user_query)]))
+                message = LLMNodeChatModelMessage(
+                    text=user_query,
+                    role=PromptMessageRole.USER,
+                    edition_type="basic",
+                )
+                prompt_messages.extend(
+                    _handle_list_messages(
+                        messages=[message],
+                        context="",
+                        jinja2_variables=[],
+                        variable_pool=variable_pool,
+                        vision_detail_config=vision_detail,
+                    )
+                )
 
         elif isinstance(prompt_template, LLMNodeCompletionModelPromptTemplate):
             # For completion model
-            prompt_messages.extend(self._handle_completion_template(template=prompt_template, context=context))
+            prompt_messages.extend(
+                _handle_completion_template(
+                    template=prompt_template,
+                    context=context,
+                    jinja2_variables=jinja2_variables,
+                    variable_pool=variable_pool,
+                )
+            )
 
             # Get memory text for completion model
-            memory_text = self._handle_memory_completion_mode(
+            memory_text = _handle_memory_completion_mode(
                 memory=memory,
                 memory_config=memory_config,
                 model_config=model_config,
@@ -628,7 +656,7 @@ class LLMNode(BaseNode[LLMNodeData]):
                     if (
                         (
                             content_item.type == PromptMessageContentType.IMAGE
-                            and (not vision_enabled or ModelFeature.VISION not in model_config.model_schema.features)
+                            and ModelFeature.VISION not in model_config.model_schema.features
                         )
                         or (
                             content_item.type == PromptMessageContentType.DOCUMENT
@@ -662,73 +690,6 @@ class LLMNode(BaseNode[LLMNodeData]):
         stop = model_config.stop
         return filtered_prompt_messages, stop
 
-    def _handle_memory_chat_mode(
-        self,
-        *,
-        memory: TokenBufferMemory | None,
-        memory_config: MemoryConfig | None,
-        model_config: ModelConfigWithCredentialsEntity,
-    ) -> Sequence[PromptMessage]:
-        memory_messages = []
-        # Get messages from memory for chat model
-        if memory and memory_config:
-            rest_tokens = self._calculate_rest_token([], model_config)
-            memory_messages = memory.get_history_prompt_messages(
-                max_token_limit=rest_tokens,
-                message_limit=memory_config.window.size if memory_config.window.enabled else None,
-            )
-        return memory_messages
-
-    def _handle_memory_completion_mode(
-        self,
-        *,
-        memory: TokenBufferMemory | None,
-        memory_config: MemoryConfig | None,
-        model_config: ModelConfigWithCredentialsEntity,
-    ) -> str:
-        memory_text = ""
-        # Get history text from memory for completion model
-        if memory and memory_config:
-            rest_tokens = self._calculate_rest_token([], model_config)
-            if not memory_config.role_prefix:
-                raise MemoryRolePrefixRequiredError("Memory role prefix is required for completion model.")
-            memory_text = memory.get_history_prompt_text(
-                max_token_limit=rest_tokens,
-                message_limit=memory_config.window.size if memory_config.window.enabled else None,
-                human_prefix=memory_config.role_prefix.user,
-                ai_prefix=memory_config.role_prefix.assistant,
-            )
-        return memory_text
-
-    def _calculate_rest_token(
-        self, prompt_messages: list[PromptMessage], model_config: ModelConfigWithCredentialsEntity
-    ) -> int:
-        rest_tokens = 2000
-
-        model_context_tokens = model_config.model_schema.model_properties.get(ModelPropertyKey.CONTEXT_SIZE)
-        if model_context_tokens:
-            model_instance = ModelInstance(
-                provider_model_bundle=model_config.provider_model_bundle, model=model_config.model
-            )
-
-            curr_message_tokens = model_instance.get_llm_num_tokens(prompt_messages)
-
-            max_tokens = 0
-            for parameter_rule in model_config.model_schema.parameter_rules:
-                if parameter_rule.name == "max_tokens" or (
-                    parameter_rule.use_template and parameter_rule.use_template == "max_tokens"
-                ):
-                    max_tokens = (
-                        model_config.parameters.get(parameter_rule.name)
-                        or model_config.parameters.get(str(parameter_rule.use_template))
-                        or 0
-                    )
-
-            rest_tokens = model_context_tokens - max_tokens - curr_message_tokens
-            rest_tokens = max(rest_tokens, 0)
-
-        return rest_tokens
-
     @classmethod
     def deduct_llm_quota(cls, tenant_id: str, model_instance: ModelInstance, usage: LLMUsage) -> None:
         provider_model_bundle = model_instance.provider_model_bundle
@@ -862,78 +823,6 @@ class LLMNode(BaseNode[LLMNodeData]):
             },
         }
 
-    def _handle_list_messages(
-        self, *, messages: Sequence[LLMNodeChatModelMessage], context: Optional[str]
-    ) -> Sequence[PromptMessage]:
-        prompt_messages = []
-        for message in messages:
-            if message.edition_type == "jinja2":
-                result_text = _render_jinja2_message(
-                    template=message.jinja2_text or "",
-                    jinjia2_variables=self.node_data.prompt_config.jinja2_variables,
-                    variable_pool=self.graph_runtime_state.variable_pool,
-                )
-                prompt_message = _combine_text_message_with_role(text=result_text, role=message.role)
-                prompt_messages.append(prompt_message)
-            else:
-                # Get segment group from basic message
-                if context:
-                    template = message.text.replace("{#context#}", context)
-                else:
-                    template = message.text
-                segment_group = self.graph_runtime_state.variable_pool.convert_template(template)
-
-                # Process segments for images
-                file_contents = []
-                for segment in segment_group.value:
-                    if isinstance(segment, ArrayFileSegment):
-                        for file in segment.value:
-                            if file.type in {FileType.IMAGE, FileType.VIDEO, FileType.AUDIO}:
-                                file_content = file_manager.to_prompt_message_content(
-                                    file, image_detail_config=self.node_data.vision.configs.detail
-                                )
-                                file_contents.append(file_content)
-                    if isinstance(segment, FileSegment):
-                        file = segment.value
-                        if file.type in {FileType.IMAGE, FileType.VIDEO, FileType.AUDIO}:
-                            file_content = file_manager.to_prompt_message_content(
-                                file, image_detail_config=self.node_data.vision.configs.detail
-                            )
-                            file_contents.append(file_content)
-
-                # Create message with text from all segments
-                plain_text = segment_group.text
-                if plain_text:
-                    prompt_message = _combine_text_message_with_role(text=plain_text, role=message.role)
-                    prompt_messages.append(prompt_message)
-
-                if file_contents:
-                    # Create message with image contents
-                    prompt_message = UserPromptMessage(content=file_contents)
-                    prompt_messages.append(prompt_message)
-
-        return prompt_messages
-
-    def _handle_completion_template(
-        self, *, template: LLMNodeCompletionModelPromptTemplate, context: Optional[str]
-    ) -> Sequence[PromptMessage]:
-        prompt_messages = []
-        if template.edition_type == "jinja2":
-            result_text = _render_jinja2_message(
-                template=template.jinja2_text or "",
-                jinjia2_variables=self.node_data.prompt_config.jinja2_variables,
-                variable_pool=self.graph_runtime_state.variable_pool,
-            )
-        else:
-            if context:
-                template = template.text.replace("{#context#}", context)
-            else:
-                template = template.text
-            result_text = self.graph_runtime_state.variable_pool.convert_template(template).text
-        prompt_message = _combine_text_message_with_role(text=result_text, role=PromptMessageRole.USER)
-        prompt_messages.append(prompt_message)
-        return prompt_messages
-
 
 def _combine_text_message_with_role(*, text: str, role: PromptMessageRole):
     match role:
@@ -966,3 +855,165 @@ def _render_jinja2_message(
     )
     result_text = code_execute_resp["result"]
     return result_text
+
+
+def _handle_list_messages(
+    *,
+    messages: Sequence[LLMNodeChatModelMessage],
+    context: Optional[str],
+    jinja2_variables: Sequence[VariableSelector],
+    variable_pool: VariablePool,
+    vision_detail_config: ImagePromptMessageContent.DETAIL,
+) -> Sequence[PromptMessage]:
+    prompt_messages = []
+    for message in messages:
+        if message.edition_type == "jinja2":
+            result_text = _render_jinja2_message(
+                template=message.jinja2_text or "",
+                jinjia2_variables=jinja2_variables,
+                variable_pool=variable_pool,
+            )
+            prompt_message = _combine_text_message_with_role(text=result_text, role=message.role)
+            prompt_messages.append(prompt_message)
+        else:
+            # Get segment group from basic message
+            if context:
+                template = message.text.replace("{#context#}", context)
+            else:
+                template = message.text
+            segment_group = variable_pool.convert_template(template)
+
+            # Process segments for images
+            file_contents = []
+            for segment in segment_group.value:
+                if isinstance(segment, ArrayFileSegment):
+                    for file in segment.value:
+                        if file.type in {FileType.IMAGE, FileType.VIDEO, FileType.AUDIO}:
+                            file_content = file_manager.to_prompt_message_content(
+                                file, image_detail_config=vision_detail_config
+                            )
+                            file_contents.append(file_content)
+                if isinstance(segment, FileSegment):
+                    file = segment.value
+                    if file.type in {FileType.IMAGE, FileType.VIDEO, FileType.AUDIO}:
+                        file_content = file_manager.to_prompt_message_content(
+                            file, image_detail_config=vision_detail_config
+                        )
+                        file_contents.append(file_content)
+
+            # Create message with text from all segments
+            plain_text = segment_group.text
+            if plain_text:
+                prompt_message = _combine_text_message_with_role(text=plain_text, role=message.role)
+                prompt_messages.append(prompt_message)
+
+            if file_contents:
+                # Create message with image contents
+                prompt_message = UserPromptMessage(content=file_contents)
+                prompt_messages.append(prompt_message)
+
+    return prompt_messages
+
+
+def _calculate_rest_token(
+    *, prompt_messages: list[PromptMessage], model_config: ModelConfigWithCredentialsEntity
+) -> int:
+    rest_tokens = 2000
+
+    model_context_tokens = model_config.model_schema.model_properties.get(ModelPropertyKey.CONTEXT_SIZE)
+    if model_context_tokens:
+        model_instance = ModelInstance(
+            provider_model_bundle=model_config.provider_model_bundle, model=model_config.model
+        )
+
+        curr_message_tokens = model_instance.get_llm_num_tokens(prompt_messages)
+
+        max_tokens = 0
+        for parameter_rule in model_config.model_schema.parameter_rules:
+            if parameter_rule.name == "max_tokens" or (
+                parameter_rule.use_template and parameter_rule.use_template == "max_tokens"
+            ):
+                max_tokens = (
+                    model_config.parameters.get(parameter_rule.name)
+                    or model_config.parameters.get(str(parameter_rule.use_template))
+                    or 0
+                )
+
+        rest_tokens = model_context_tokens - max_tokens - curr_message_tokens
+        rest_tokens = max(rest_tokens, 0)
+
+    return rest_tokens
+
+
+def _handle_memory_chat_mode(
+    *,
+    memory: TokenBufferMemory | None,
+    memory_config: MemoryConfig | None,
+    model_config: ModelConfigWithCredentialsEntity,
+) -> Sequence[PromptMessage]:
+    memory_messages = []
+    # Get messages from memory for chat model
+    if memory and memory_config:
+        rest_tokens = _calculate_rest_token(prompt_messages=[], model_config=model_config)
+        memory_messages = memory.get_history_prompt_messages(
+            max_token_limit=rest_tokens,
+            message_limit=memory_config.window.size if memory_config.window.enabled else None,
+        )
+    return memory_messages
+
+
+def _handle_memory_completion_mode(
+    *,
+    memory: TokenBufferMemory | None,
+    memory_config: MemoryConfig | None,
+    model_config: ModelConfigWithCredentialsEntity,
+) -> str:
+    memory_text = ""
+    # Get history text from memory for completion model
+    if memory and memory_config:
+        rest_tokens = _calculate_rest_token(prompt_messages=[], model_config=model_config)
+        if not memory_config.role_prefix:
+            raise MemoryRolePrefixRequiredError("Memory role prefix is required for completion model.")
+        memory_text = memory.get_history_prompt_text(
+            max_token_limit=rest_tokens,
+            message_limit=memory_config.window.size if memory_config.window.enabled else None,
+            human_prefix=memory_config.role_prefix.user,
+            ai_prefix=memory_config.role_prefix.assistant,
+        )
+    return memory_text
+
+
+def _handle_completion_template(
+    *,
+    template: LLMNodeCompletionModelPromptTemplate,
+    context: Optional[str],
+    jinja2_variables: Sequence[VariableSelector],
+    variable_pool: VariablePool,
+) -> Sequence[PromptMessage]:
+    """Handle completion template processing outside of LLMNode class.
+
+    Args:
+        template: The completion model prompt template
+        context: Optional context string
+        jinja2_variables: Variables for jinja2 template rendering
+        variable_pool: Variable pool for template conversion
+
+    Returns:
+        Sequence of prompt messages
+    """
+    prompt_messages = []
+    if template.edition_type == "jinja2":
+        result_text = _render_jinja2_message(
+            template=template.jinja2_text or "",
+            jinjia2_variables=jinja2_variables,
+            variable_pool=variable_pool,
+        )
+    else:
+        if context:
+            template_text = template.text.replace("{#context#}", context)
+        else:
+            template_text = template.text
+        result_text = variable_pool.convert_template(template_text).text
+    prompt_message = _combine_text_message_with_role(text=result_text, role=PromptMessageRole.USER)
+    prompt_messages.append(prompt_message)
+    return prompt_messages

api/core/workflow/nodes/question_classifier/question_classifier_node.py

@@ -86,12 +86,14 @@ class QuestionClassifierNode(LLMNode):
         )
         prompt_messages, stop = self._fetch_prompt_messages(
             prompt_template=prompt_template,
-            system_query=query,
+            user_query=query,
             memory=memory,
             model_config=model_config,
-            files=files,
+            user_files=files,
             vision_enabled=node_data.vision.enabled,
             vision_detail=node_data.vision.configs.detail,
+            variable_pool=variable_pool,
+            jinja2_variables=[],
         )
 
         # handle invoke result

api/tests/unit_tests/core/workflow/nodes/llm/test_node.py

@@ -240,6 +240,8 @@ def test_fetch_prompt_messages__vison_disabled(faker, llm_node, model_config):
         memory_config=None,
         vision_enabled=False,
         vision_detail=fake_vision_detail,
+        variable_pool=llm_node.graph_runtime_state.variable_pool,
+        jinja2_variables=[],
     )
 
     assert prompt_messages == [UserPromptMessage(content=fake_query)]
@@ -368,7 +370,7 @@ def test_fetch_prompt_messages__basic(faker, llm_node, model_config):
             description="Prompt template with variable selector of File",
             user_query=fake_query,
             user_files=[],
-            vision_enabled=True,
+            vision_enabled=False,
             vision_detail=fake_vision_detail,
             features=[ModelFeature.VISION],
             window_size=fake_window_size,
@@ -471,6 +473,8 @@ def test_fetch_prompt_messages__basic(faker, llm_node, model_config):
             memory_config=memory_config,
             vision_enabled=scenario.vision_enabled,
             vision_detail=scenario.vision_detail,
+            variable_pool=llm_node.graph_runtime_state.variable_pool,
+            jinja2_variables=[],
         )
 
         # Verify the result