middleware

Middleware Example

This example demonstrates how to use middleware in DotWeb.

Features

• Global middleware
• Route-level middleware
• Group-level middleware
• Exclude specific routes
• Custom middleware implementation

Running

cd example/middleware
go run main.go

Middleware Types

1. Global Middleware

Applied to all routes:

app.Use(NewAccessFmtLog("app"))

2. Route-level Middleware

Applied to specific routes:

server.Router().GET("/use", Index).Use(NewAccessFmtLog("Router-use"))

3. Group-level Middleware

Applied to all routes in a group:

g := server.Group("/api").Use(NewAuthMiddleware("secret"))
g.GET("/users", listUsers)

4. Exclude Routes

Skip middleware for specific routes:

middleware := NewAccessFmtLog("appex")
middleware.Exclude("/index")
middleware.Exclude("/v1/machines/queryIP/:IP")
app.Use(middleware)

// Or exclude from first middleware
app.ExcludeUse(NewAccessFmtLog("appex1"), "/")

Custom Middleware

func NewAccessFmtLog(name string) dotweb.HandlerFunc {
    return func(ctx dotweb.Context) error {
        // Before handler
        start := time.Now()
        log.Printf("[%s] %s %s", name, ctx.Request().Method, ctx.Request().Url())
        
        // Call next handler
        err := ctx.NextHandler()
        
        // After handler
        duration := time.Since(start)
        log.Printf("[%s] Request took %v", name, duration)
        
        return err
    }
}

Testing

# All routes go through middleware
curl http://localhost:8080/
curl http://localhost:8080/index

# Check middleware chain in group routes
curl http://localhost:8080/A/
curl http://localhost:8080/A/B/
curl http://localhost:8080/A/C/

Middleware Chain

When using groups with middleware, they form a chain:

Global Middleware
    ↓
Group Middleware (A)
    ↓
Group Middleware (B)
    ↓
Route Middleware
    ↓
Handler

Use ctx.RouterNode().GroupMiddlewares() to inspect the chain.

API Reference

Notes

• Middleware is executed in the order they are added
• Call ctx.NextHandler() to pass control to the next middleware
• Without ctx.NextHandler(), the middleware chain stops
• Use Exclude() to skip middleware for certain routes