feat(invocation): add FetchAppInvocation and update type hints for improved clarity (#100)

* feat(invocation): add FetchAppInvocation and update type hints for improved clarity

- Introduced FetchAppInvocation class to handle fetching app data.
- Updated type hints in ToolInvokeMessage and related classes to use Mapping for better type safety.
- Added FetchApp enum value to InvokeType for consistency in invocation types.

* apply ruff

Author: Yeuoly

python/dify_plugin/core/entities/invocation.py

@@ -15,6 +15,7 @@ class InvokeType(Enum):
     Storage = "storage"
     UploadFile = "upload_file"
     SYSTEM_SUMMARY = "system_summary"
+    FetchApp = "fetch_app"
 
     @classmethod
     def value_of(cls, value: str) -> "InvokeType":

python/dify_plugin/core/runtime.py

@@ -1,7 +1,7 @@
 import json
 import uuid
 from abc import ABC
-from collections.abc import Generator
+from collections.abc import Generator, Mapping
 from concurrent.futures import ThreadPoolExecutor
 from enum import Enum
 from typing import Generic, Optional, TypeVar, Union
@@ -46,13 +46,18 @@ def __init__(self, session: "Session") -> None:
 
 class AppInvocations:
     def __init__(self, session: "Session"):
+        from dify_plugin.invocations.app import FetchAppInvocation
         from dify_plugin.invocations.app.chat import ChatAppInvocation
         from dify_plugin.invocations.app.completion import CompletionAppInvocation
         from dify_plugin.invocations.app.workflow import WorkflowAppInvocation
 
         self.chat = ChatAppInvocation(session)
         self.completion = CompletionAppInvocation(session)
         self.workflow = WorkflowAppInvocation(session)
+        self.fetch_app_invocation = FetchAppInvocation(session)
+
+    def fetch_app(self, app_id: str) -> Mapping:
+        return self.fetch_app_invocation.get(app_id)
 
 
 class WorkflowNodeInvocations:

python/dify_plugin/entities/tool.py

@@ -81,7 +81,7 @@ def to_dict(self):
             return {"text": self.text}
 
     class JsonMessage(BaseModel):
-        json_object: dict
+        json_object: Mapping
 
         def to_dict(self):
             return {"json_object": self.json_object}

python/dify_plugin/interfaces/tool/__init__.py

@@ -25,7 +25,7 @@ def create_text_message(self, text: str) -> T:
             message=ToolInvokeMessage.TextMessage(text=text),
         )
 
-    def create_json_message(self, json: dict) -> T:
+    def create_json_message(self, json: Mapping) -> T:
         return self.response_type(
             type=ToolInvokeMessage.MessageType.JSON,
             message=ToolInvokeMessage.JsonMessage(json_object=json),

python/dify_plugin/invocations/app/__init__.py

@@ -0,0 +1,26 @@
+from collections.abc import Mapping
+
+from dify_plugin.core.entities.invocation import InvokeType
+from dify_plugin.core.runtime import BackwardsInvocation
+
+
+class FetchAppInvocation(BackwardsInvocation[dict]):
+    def get(
+        self,
+        app_id: str,
+    ) -> Mapping:
+        """
+        Invoke chat app
+        """
+        response = self._backwards_invoke(
+            InvokeType.FetchApp,
+            dict,
+            {
+                "app_id": app_id,
+            },
+        )
+
+        for data in response:
+            return data
+
+        raise Exception("No response")