mart337i / importreflectionfastapi

Use of reflection for FastApi

The traversal works by using the os.walk function to recursively walk through the "addons" directory and its subdirectories, identifying all Python files:

1. Directory Structure:

   addons/
   ├── test1/
   │   ├── models/
   │   │   └── model.py
   │   └── routes/
   │       └── test1_service.py
   ├── test2/
   │   ├── models/
   │   │   └── model.py
   │   └── routes/
   │       └── test2_service.py
   

2. Traversal Process:

   • The os.walk function is called with the "addons" directory.
   • It recursively visits each subdirectory and collects all files.

3. Example of os.walk Output:

   • For the given structure, os.walk will generate:

     root = 'addons'
     dirs = ['test1', 'test2']
     files = []
     
     root = 'addons/test1'
     dirs = ['models', 'routes']
     files = []
     
     root = 'addons/test1/models'
     dirs = []
     files = ['model.py']
     
     root = 'addons/test1/routes'
     dirs = []
     files = ['test1_service.py']
     
     root = 'addons/test2'
     dirs = ['models', 'routes']
     files = []
     
     root = 'addons/test2/models'
     dirs = []
     files = ['model.py']
     
     root = 'addons/test2/routes'
     dirs = []
     files = ['test2_service.py']
     

4. Processing Each File:

   • For each file found, the relative path from "addons" is determined.
   • The file path is converted to a module path by replacing directory separators with dots (.) and removing the .py extension.

5. Example of Module Path Conversion:

   • addons/test1/routes/test1_service.py becomes addons.test1.routes.test1_service
   • addons/test2/routes/test2_service.py becomes addons.test2.routes.test2_service

6. Including the Router:

   • Each constructed module path is passed to the include_router_from_module function to import the module and include its router in the FastAPI application if it exists.

The include_router_from_module function is responsible for dynamically importing a module and checking if it contains a router attribute, which is then included in the FastAPI application. Here's a detailed explanation of how this function works:

1. Function Definition:

   def include_router_from_module(module_name: str):

2. Importing the Module:

   • The function attempts to import the module using importlib.import_module(module_name).

   module = importlib.import_module(module_name)

3. Checking for router Attribute:

   • It checks if the imported module has an attribute named router using hasattr(module, 'router').

   if hasattr(module, 'router'):

4. Including the Router:

   • If the router attribute exists, the function includes it in the FastAPI application using app.include_router.

   app.include_router(router=module.router)

5. Logging the Success:

   • A message is printed to the console indicating that the router from the module was successfully registered.

   print(f"Registered router from module: {module_name}")

6. Exception Handling:

   • The function includes exception handling to manage cases where the module cannot be found or does not have a router attribute.
   • If a ModuleNotFoundError occurs, it prints an error message indicating that the module was not found.

   except ModuleNotFoundError as e:
       print(f"Module not found: {module_name}, error: {e}")

   • If an AttributeError occurs because the module does not have a router attribute, it prints an error message.

   except AttributeError as e:
       print(f"Module '{module_name}' does not have 'router' attribute, error: {e}")