Global Options

Overview

vel provides a global configuration system through the GlobalOpts variable, allowing you to customize framework behavior across all handlers.

GlobalOpts Structure

The GlobalOpts variable is of type Opts and provides the following configuration options:

type Opts struct {
    ProcessErr       func(r *http.Request, e *Error)
    MapCodeToStatus  func(code string) int
    SkipOptionMethod bool
}

var GlobalOpts = Opts{
    ProcessErr: nil,
    MapCodeToStatus: func(code string) int {
        if code == "" {
            return http.StatusInternalServerError
        }
        return http.StatusBadRequest
    },
    SkipOptionMethod: false,
}

Configuration Options

1. ProcessErr - Custom error processing function called before errors are returned to clients
2. MapCodeToStatus - Function that maps error codes to HTTP status codes
3. SkipOptionMethod - Boolean flag to control automatic OPTIONS method handling

Default Behavior

• ProcessErr: nil (no custom error processing)
• MapCodeToStatus: Returns 500 for empty error codes, 400 for all others
• SkipOptionMethod: false (automatic OPTIONS handling enabled)

Custom Error Processing

Configure global error processing with the ProcessErr function to implement logging, metrics, and custom error handling.

Basic Error Processing

vel.GlobalOpts.ProcessErr = func(r *http.Request, e *vel.Error) {
    // Log errors with request context
    log.Printf("API Error: %s - %s [%s %s]",
        e.Code, e.Message, r.Method, r.URL.Path)
}

HTTP Status Code Mapping

Configure how error codes map to HTTP status codes using the MapCodeToStatus function.

Default Status Code Mapping

// Default implementation
vel.GlobalOpts.MapCodeToStatus = func(code string) int {
    if code == "" {
        return http.StatusInternalServerError // 500
    }
    return http.StatusBadRequest // 400
}

OPTIONS Method Handling

Control automatic OPTIONS method registration with the SkipOptionMethod option.

Default OPTIONS Handling

By default, vel automatically registers OPTIONS handlers for all registered routes:

// Default behavior - OPTIONS handlers are automatically created
vel.GlobalOpts.SkipOptionMethod = false

// Register a POST handler
vel.RegisterPost(router, "users", CreateUserHandler)

// vel automatically registers:
// OPTIONS /users -> returns 200 OK

Disabling Automatic OPTIONS

// Disable automatic OPTIONS handling
vel.GlobalOpts.SkipOptionMethod = true