How to Pass Additional Arguments to Gorilla Mux Handlers?

Passing Arguments to Gorilla Mux Handlers

In Gorilla Mux, handlers are typically registered using the HandleFunc method, which takes a function that accepts a http.ResponseWriter and a *http.Request as arguments.

Limitations of Standard Method

However, when you require additional arguments in your handlers, such as a database object, the default HandleFunc method has limitations. It only accepts two arguments, making it challenging to pass additional parameters.

Possible Solutions

There are a few workarounds to overcome this limitation:

1. Global Variables:
   While it is generally discouraged in Go, it is acceptable to use global variables for database objects. This provides easy access to the database from any handler.

2. Struct-Based Handlers:
   Create a custom handler struct and define methods that take the necessary arguments. The struct can then be embedded in the handler function.

   type Users struct {
       db *gorm.DB
   }
   
   func (users *Users) ShowUserHandler(w http.ResponseWriter, r *http.Request) {
       // Access to the database object through users.db
   }
   
   // Register the handler
   router.HandleFunc("/users/{id}", users.ShowUserHandler).Methods("GET")

3. Wrapper Function:
   Wrap the actual handler in a wrapper function that provides the additional arguments.

   db := createDB()
   router.HandleFunc("/users/{id}", func(w http.ResponseWriter, r *http.Request) {
       ShowUserHandler(w, r, db)
   }).Method("GET")

The choice of approach depends on your application's requirements and preference. If you prefer not to have global database objects or require more than one instance of the database, the struct-based or wrapper function methods provide more flexibility.

The above is the detailed content of How to Pass Additional Arguments to Gorilla Mux Handlers?. For more information, please follow other related articles on the PHP Chinese website!