Dependency Injection
Batman wanted to learn about dependency injection in Robyn. Robyn introduced him to the concept of dependency injection and how it can be used in Robyn.
Robyn has two types of dependency injection: One is for the application level and the other is for the router level.
Application Level Dependency Injection
Application level dependency injection is used to inject dependencies into the application. These dependencies are available to all the requests.
Request
from robyn import Robyn, ALLOW_CORS
app = Robyn(__file__)
GLOBAL_DEPENDENCY = "GLOBAL DEPENDENCY"
app.inject_global(GLOBAL_DEPENDENCY=GLOBAL_DEPENDENCY)
@app.get("/sync/global_di")
def sync_global_di(request, global_dependencies):
return global_dependencies["GLOBAL_DEPENDENCY"]
Router Level Dependency Injection
Router level dependency injection is used to inject dependencies into the router. These dependencies are available to all the requests of that router.
Request
from robyn import Robyn, ALLOW_CORS
app = Robyn(__file__)
ROUTER_DEPENDENCY = "ROUTER DEPENDENCY"
app.inject(ROUTER_DEPENDENCY=ROUTER_DEPENDENCY)
@app.get("/sync/global_di")
def sync_global_di(r, router_dependencies): # r is the request object
return router_dependencies["ROUTER_DEPENDENCY"]
Note: router_dependencies
, global_dependencies
are reserved parameters and must be named as such. The order of the parameters does not matter among them. However, the router_dependencies
and global_dependencies
must only come after the request
parameter.
What's next?
Batman, being the familiar with the dark side wanted to know about Exceptions!
Robyn introduced him to the concept of exceptions and how he can use them to handle errors in his application.