Request
Retrieve Data
Form Data
Form data can be retrieved by name using Context#FormValue(name string).
e.POST("/form",func(c *echo.Context)error{
name := c.FormValue("name")
return c.String(http.StatusOK, name)
})
For types other than string you can use echo.FormValue[t] genetic type function.
age, err := echo.FormValue[int](c,"age")
if err !=nil{
return err
}
Test with:
curl -X POST http://localhost:1323 -d 'name=Joe&age=30'
To bind a custom data type, you can implement Echo#BindUnmarshaler interface.
type Timestamp time.Time
func(t *Timestamp)UnmarshalParam(src string)error{
ts, err := time.Parse(time.RFC3339, src)
*t =Timestamp(ts)
return err
}
Query Parameters
Query parameters can be retrieved by name using Context#QueryParam(name string).
// Handler
func(c *echo.Context)error{
name := c.QueryParam("name")
return c.String(http.StatusOK, name)
})
For types other than string you can use echo.QueryParam[t] genetic type function.
age, err := echo.QueryParam[int](c,"age")
if err !=nil{
return err
}
curl -X GET "http://localhost:1323?name=Joe&age=30"
Path Parameters
Registered path parameters can be retrieved by name using Context#Param(name string) string.
e.GET("/users/:name",func(c *echo.Context)error{
name := c.Param("name")
return c.String(http.StatusOK, name)
})
For types other than string you can use echo.PathParam[t] genetic type function.
ID, err := echo.PathParam[int](c,"id")
if err !=nil{
return err
}
curl http://localhost:1323/users/Joe
curl http://localhost:1323/users/123
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:
package main
import(
"context"
"fmt"
"net/http"
"github.com/go-playground/validator/v10"// installed by `go get github.com/go-playground/validator/v10`
"github.com/labstack/echo/v5"
)
type CustomValidator struct{
validator *validator.Validate
}
func(cv *CustomValidator)Validate(i any)error{
if err := cv.validator.Struct(i); err !=nil{
// Optionally, you could return the error to give each route more control over the status code
return echo.ErrBadRequest.Wrap(err)
}
returnnil
}
type User struct{
Name string`json:"name" validate:"required"`
Email string`json:"email" validate:"required,email"`
}
funcmain(){
e := echo.New()
e.Validator =&CustomValidator{validator: validator.New()}
e.POST("/users",func(c *echo.Context)(err error){
u :=new(User)
if err = c.Bind(u); err !=nil{
return err
}
if err = c.Validate(u); err !=nil{
return err
}
return c.JSON(http.StatusOK, u)
})
if err := e.Start(":1323"); err !=nil{
e.Logger.Error("failed to start server","error", err)
}
}
curl -X POST http://localhost:1323/users \
-H 'Content-Type: application/json' \
-d '{"name":"Joe","email":"joe@invalid-domain"}'
{"message":"Key: 'User.Email' Error:Field validation for 'Email' failed on the 'email' tag"}