Request and Response Middleware
Request Middleware
Use Client.OnBeforeRequest to set request middleware, you can access Client and current Request object to do something what you need before the Request is sent:
client := req.C()
// Registering Request Middleware
client.OnBeforeRequest(func(client *req.Client, req *req.Request) error {
// You can access Client and current Request object to do something
// as you need
return nil // return nil if it is success
})
Response Middleware
Use Client.OnAfterResponse to set response middleware, you can access Client and current Request object to do something what you need before the Response is returned:
client := req.C()
// Registering Response Middleware
client.OnAfterResponse(func(client *req.Client, resp *req.Response) error {
if resp.Err != nil { // you can skip if error occurs.
return nil
}
// You can access Client and current Response object to do something
// as you need
return nil // return nil if it is success
})
If an error occurs, resp.Err will not be nil, you can judge whether an error occurs inside the middleware function to decide whether to skip the execution of subsequent logic. For scenarios such as recording metrics or tracing information, you want to execute it regardless of whether there is an error, you don’t need to judge.