Request

Retrieve Data

Form Data

Form data can be retrieved by name using Context#FormValue(name string).

  1. // Handler
  2. func(c echo.Context) error {
  3.   name := c.FormValue("name")
  4.   return c.String(http.StatusOK, name)
  5. }
  1. curl -X POST http://localhost:1323 -d 'name=Joe'

To bind a custom data type, you can implement Echo#BindUnmarshaler interface.

  1. type Timestamp time.Time
  3. func (t *Timestamp) UnmarshalParam(src string) error {
  4.   ts, err := time.Parse(time.RFC3339, src)
  5.   *t = Timestamp(ts)
  6.   return err
  7. }

Query Parameters

Query parameters can be retrieved by name using Context#QueryParam(name string).

  1. // Handler
  2. func(c echo.Context) error {
  3.   name := c.QueryParam("name")
  4.   return c.String(http.StatusOK, name)
  5. })
  1. curl \
  2.   -X GET \
  3.   http://localhost:1323\?name\=Joe

Similar to form data, custom data type can be bind using Context#QueryParam(name string).

Path Parameters

Registered path parameters can be retrieved by name using Context#Param(name string) string.

  1. e.GET("/users/:name", func(c echo.Context) error {
  2.   name := c.Param("name")
  3.   return c.String(http.StatusOK, name)
  4. })
  1. curl http://localhost:1323/users/Joe

Binding Data

Also binding of request data to native Go structs and variables is supported. See Binding Data

Validate Data

Echo doesn’t have built-in data validation capabilities, however, you can register a custom validator using Echo#Validator and leverage third-party libraries.

Example below uses https://github.com/go-playground/validator framework for validation:

  1. package main
  3. import (
  4.   "net/http"
  6.   "github.com/go-playground/validator"
  7.   "github.com/labstack/echo/v4"
  8.   "github.com/labstack/echo/v4/middleware"
  9. )
  11. type (
  12.   User struct {
  13.     Name  string `json:"name" validate:"required"`
  14.     Email string `json:"email" validate:"required,email"`
  15.   }
  17.   CustomValidator struct {
  18.     validator *validator.Validate
  19.   }
  20. )
  22. func (cv *CustomValidator) Validate(i interface{}) error {
  23.   if err := cv.validator.Struct(i); err != nil {
  24.     // Optionally, you could return the error to give each route more control over the status code
  25.     return echo.NewHTTPError(http.StatusBadRequest, err.Error())
  26.   }
  27.   return nil
  28. }
  30. func main() {
  31.   e := echo.New()
  32.   e.Validator = &CustomValidator{validator: validator.New()}
  33.   e.POST("/users", func(c echo.Context) (err error) {
  34.     u := new(User)
  35.     if err = c.Bind(u); err != nil {
  36.       return echo.NewHTTPError(http.StatusBadRequest, err.Error())
  37.     }
  38.     if err = c.Validate(u); err != nil {
  39.       return err
  40.     }
  41.     return c.JSON(http.StatusOK, u)
  42.   })
  43.   e.Logger.Fatal(e.Start(":1323"))
  44. }
  1. curl -X POST http://localhost:1323/users \
  2.   -H 'Content-Type: application/json' \
  3.   -d '{"name":"Joe","email":"joe@invalid-domain"}'
  4. {"message":"Key: 'User.Email' Error:Field validation for 'Email' failed on the 'email' tag"}