FEAT: NEW WORKFLOW ENGINE (#3160)

Co-authored-by: Joel <iamjoel007@gmail.com>
Co-authored-by: Yeuoly <admin@srmxy.cn>
Co-authored-by: JzoNg <jzongcode@gmail.com>
Co-authored-by: StyleZhang <jasonapring2015@outlook.com>
Co-authored-by: jyong <jyong@dify.ai>
Co-authored-by: nite-knite <nkCoding@gmail.com>
Co-authored-by: jyong <718720800@qq.com>

api/core/workflow/nodes/answer/answer_node.py

@@ -0,0 +1,155 @@
+import json
+from typing import cast
+
+from core.file.file_obj import FileVar
+from core.prompt.utils.prompt_template_parser import PromptTemplateParser
+from core.workflow.entities.base_node_data_entities import BaseNodeData
+from core.workflow.entities.node_entities import NodeRunResult, NodeType
+from core.workflow.entities.variable_pool import VariablePool
+from core.workflow.nodes.answer.entities import (
+    AnswerNodeData,
+    GenerateRouteChunk,
+    TextGenerateRouteChunk,
+    VarGenerateRouteChunk,
+)
+from core.workflow.nodes.base_node import BaseNode
+from core.workflow.utils.variable_template_parser import VariableTemplateParser
+from models.workflow import WorkflowNodeExecutionStatus
+
+
+class AnswerNode(BaseNode):
+    _node_data_cls = AnswerNodeData
+    node_type = NodeType.ANSWER
+
+    def _run(self, variable_pool: VariablePool) -> NodeRunResult:
+        """
+        Run node
+        :param variable_pool: variable pool
+        :return:
+        """
+        node_data = self.node_data
+        node_data = cast(self._node_data_cls, node_data)
+
+        # generate routes
+        generate_routes = self.extract_generate_route_from_node_data(node_data)
+
+        answer = ''
+        for part in generate_routes:
+            if part.type == "var":
+                part = cast(VarGenerateRouteChunk, part)
+                value_selector = part.value_selector
+                value = variable_pool.get_variable_value(
+                    variable_selector=value_selector
+                )
+
+                text = ''
+                if isinstance(value, str | int | float):
+                    text = str(value)
+                elif isinstance(value, dict):
+                    # other types
+                    text = json.dumps(value, ensure_ascii=False)
+                elif isinstance(value, FileVar):
+                    # convert file to markdown
+                    text = value.to_markdown()
+                elif isinstance(value, list):
+                    for item in value:
+                        if isinstance(item, FileVar):
+                            text += item.to_markdown() + ' '
+
+                    text = text.strip()
+
+                    if not text and value:
+                        # other types
+                        text = json.dumps(value, ensure_ascii=False)
+
+                answer += text
+            else:
+                part = cast(TextGenerateRouteChunk, part)
+                answer += part.text
+
+        return NodeRunResult(
+            status=WorkflowNodeExecutionStatus.SUCCEEDED,
+            outputs={
+                "answer": answer
+            }
+        )
+
+    @classmethod
+    def extract_generate_route_selectors(cls, config: dict) -> list[GenerateRouteChunk]:
+        """
+        Extract generate route selectors
+        :param config: node config
+        :return:
+        """
+        node_data = cls._node_data_cls(**config.get("data", {}))
+        node_data = cast(cls._node_data_cls, node_data)
+
+        return cls.extract_generate_route_from_node_data(node_data)
+
+    @classmethod
+    def extract_generate_route_from_node_data(cls, node_data: AnswerNodeData) -> list[GenerateRouteChunk]:
+        """
+        Extract generate route from node data
+        :param node_data: node data object
+        :return:
+        """
+        variable_template_parser = VariableTemplateParser(template=node_data.answer)
+        variable_selectors = variable_template_parser.extract_variable_selectors()
+
+        value_selector_mapping = {
+            variable_selector.variable: variable_selector.value_selector
+            for variable_selector in variable_selectors
+        }
+
+        variable_keys = list(value_selector_mapping.keys())
+
+        # format answer template
+        template_parser = PromptTemplateParser(template=node_data.answer, with_variable_tmpl=True)
+        template_variable_keys = template_parser.variable_keys
+
+        # Take the intersection of variable_keys and template_variable_keys
+        variable_keys = list(set(variable_keys) & set(template_variable_keys))
+
+        template = node_data.answer
+        for var in variable_keys:
+            template = template.replace(f'{{{{{var}}}}}', f'Ω{{{{{var}}}}}Ω')
+
+        generate_routes = []
+        for part in template.split('Ω'):
+            if part:
+                if cls._is_variable(part, variable_keys):
+                    var_key = part.replace('Ω', '').replace('{{', '').replace('}}', '')
+                    value_selector = value_selector_mapping[var_key]
+                    generate_routes.append(VarGenerateRouteChunk(
+                        value_selector=value_selector
+                    ))
+                else:
+                    generate_routes.append(TextGenerateRouteChunk(
+                        text=part
+                    ))
+
+        return generate_routes
+
+    @classmethod
+    def _is_variable(cls, part, variable_keys):
+        cleaned_part = part.replace('{{', '').replace('}}', '')
+        return part.startswith('{{') and cleaned_part in variable_keys
+
+    @classmethod
+    def _extract_variable_selector_to_variable_mapping(cls, node_data: BaseNodeData) -> dict[str, list[str]]:
+        """
+        Extract variable selector to variable mapping
+        :param node_data: node data
+        :return:
+        """
+        node_data = node_data
+        node_data = cast(cls._node_data_cls, node_data)
+
+        variable_template_parser = VariableTemplateParser(template=node_data.answer)
+        variable_selectors = variable_template_parser.extract_variable_selectors()
+
+        variable_mapping = {}
+        for variable_selector in variable_selectors:
+            variable_mapping[variable_selector.variable] = variable_selector.value_selector
+
+        return variable_mapping

api/core/workflow/nodes/answer/entities.py

@@ -0,0 +1,34 @@
+
+from pydantic import BaseModel
+
+from core.workflow.entities.base_node_data_entities import BaseNodeData
+
+
+class AnswerNodeData(BaseNodeData):
+    """
+    Answer Node Data.
+    """
+    answer: str
+
+
+class GenerateRouteChunk(BaseModel):
+    """
+    Generate Route Chunk.
+    """
+    type: str
+
+
+class VarGenerateRouteChunk(GenerateRouteChunk):
+    """
+    Var Generate Route Chunk.
+    """
+    type: str = "var"
+    value_selector: list[str]
+
+
+class TextGenerateRouteChunk(GenerateRouteChunk):
+    """
+    Text Generate Route Chunk.
+    """
+    type: str = "text"
+    text: str