Echo Framework Standards
Application Setup
package main
import (
"github.com/labstack/echo/v4"
"github.com/labstack/echo/v4/middleware"
)
func main() {
e := echo.New()
// Middleware
e.Use(middleware.Logger())
e.Use(middleware.Recover())
e.Use(middleware.CORS())
// Routes
e.GET("/", homeHandler)
e.GET("/users/:id", getUser)
e.POST("/users", createUser)
// Groups
api := e.Group("/api/v1")
api.GET("/items", listItems)
e.Logger.Fatal(e.Start(":8080"))
}
Handlers
// Path parameters
func getUser(c echo.Context) error {
id := c.Param("id")
user, err := findUser(id)
if err != nil {
return echo.NewHTTPError(404, "User not found")
}
return c.JSON(200, user)
}
// Query parameters
func listUsers(c echo.Context) error {
page := c.QueryParam("page")
limit := c.QueryParam("limit")
users := fetchUsers(page, limit)
return c.JSON(200, users)
}
// JSON body binding
type CreateUserRequest struct {
Name string `json:"name" validate:"required"`
Email string `json:"email" validate:"required,email"`
}
func createUser(c echo.Context) error {
var req CreateUserRequest
if err := c.Bind(&req); err != nil {
return echo.NewHTTPError(400, err.Error())
}
if err := c.Validate(&req); err != nil {
return err
}
user := insertUser(req)
return c.JSON(201, user)
}
Validation
import "github.com/go-playground/validator/v10"
type CustomValidator struct {
validator *validator.Validate
}
func (cv *CustomValidator) Validate(i interface{}) error {
if err := cv.validator.Struct(i); err != nil {
return echo.NewHTTPError(400, err.Error())
}
return nil
}
func main() {
e := echo.New()
e.Validator = &CustomValidator{validator: validator.New()}
}
Middleware
// Built-in middleware
e.Use(middleware.Logger())
e.Use(middleware.Recover())
e.Use(middleware.CORS())
e.Use(middleware.Gzip())
e.Use(middleware.RateLimiter(middleware.NewRateLimiterMemoryStore(20)))
// JWT middleware
e.Use(middleware.JWTWithConfig(middleware.JWTConfig{
SigningKey: []byte("secret"),
Claims: &JwtCustomClaims{},
}))
// Custom middleware
func authMiddleware(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
token := c.Request().Header.Get("Authorization")
if token == "" {
return echo.NewHTTPError(401, "Unauthorized")
}
user, err := validateToken(token)
if err != nil {
return echo.NewHTTPError(401, "Invalid token")
}
c.Set("user", user)
return next(c)
}
}
// Apply middleware to group
api := e.Group("/api", authMiddleware)
Error Handling
// Custom HTTP error handler
e.HTTPErrorHandler = func(err error, c echo.Context) {
code := 500
message := "Internal Server Error"
if he, ok := err.(*echo.HTTPError); ok {
code = he.Code
message = he.Message.(string)
}
c.JSON(code, map[string]string{
"error": message,
})
}
// In handlers
func handler(c echo.Context) error {
if notFound {
return echo.NewHTTPError(404, "Resource not found")
}
return c.JSON(200, data)
}
Response Types
// JSON
c.JSON(200, user)
// String
c.String(200, "Hello, World!")
// HTML
c.HTML(200, "<h1>Hello</h1>")
// File
c.File("path/to/file.pdf")
// Stream
c.Stream(200, "text/csv", reader)
// Redirect
c.Redirect(301, "/new-location")
// No Content
c.NoContent(204)
Context Values
// Set value
c.Set("user", user)
// Get value
user := c.Get("user").(*User)
// Request context
ctx := c.Request().Context()
Best Practices
- Validation: Always validate input with custom validator
- Error handling: Use
echo.NewHTTPError for HTTP errors
- Context: Don't store echo.Context outside request lifecycle
- Middleware order: Logger first, then Recover, then custom
- Graceful shutdown: Use
e.Shutdown(ctx) for graceful shutdown
ngxtm