Interceptors

Coming Soon — This feature is not yet implemented.

Interceptors provide a way to bind extra logic before and after method execution. They are useful for logging, response transformation, caching, and error handling.

Planned Design

// Planned API (subject to change)
type Interceptor interface {
    Intercept(ctx *gin.Context, handler gin.HandlerFunc) gin.HandlerFunc
}

// Logging interceptor
type LoggingInterceptor struct{}

func (i *LoggingInterceptor) Intercept(ctx *gin.Context, handler gin.HandlerFunc) gin.HandlerFunc {
    return func(c *gin.Context) {
        start := time.Now()
        log.Printf("→ Request: %s %s", c.Request.Method, c.Request.URL.Path)

        handler(c)

        log.Printf("← Response: %d (%v)", c.Writer.Status(), time.Since(start))
    }
}

// Response transformation interceptor
type TransformInterceptor struct{}

func (i *TransformInterceptor) Intercept(ctx *gin.Context, handler gin.HandlerFunc) gin.HandlerFunc {
    return func(c *gin.Context) {
        // Wrap response writer
        // Call handler
        // Transform response
        handler(c)
    }
}

Current Alternative

Use Gin middleware as a workaround:

// Response wrapper middleware
func ResponseWrapper() gin.HandlerFunc {
    return func(c *gin.Context) {
        // Before handler
        start := time.Now()

        c.Next()

        // After handler — you can modify the response here
        duration := time.Since(start)
        c.Header("X-Response-Time", duration.String())
    }
}

// Usage
app.Use(ResponseWrapper())

Use Cases

Use Case	Description
Logging	Log requests and responses
Response transformation	Wrap all responses in a standard format
Caching	Cache responses
Error handling	Catch and transform errors
Performance monitoring	Measure handler execution time

Status

Feature	Status
Interceptor interface	⏳ Planned
Global interceptors	⏳ Planned
Per-route interceptors	⏳ Planned
Response mapping	⏳ Planned

Want to contribute?

This feature is open for contribution. Check out the GitHub repository for guidelines.