Started on improved documentation for model binding

This commit is contained in:
Alexander Nyquist 2014-08-03 01:31:48 +02:00
parent c3abaf9afc
commit 38dcdcc985

View File

@ -196,30 +196,53 @@ func main() {
}
```
#### Model binding and validation
#### JSON parsing and validation
To bind a request body into a type, use model binding. We currently support binding of JSON, XML and standard form values (foo=bar&boo=baz).
Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set `json:"fieldname"`.
When using the Bind-method, Gin tries to infer the binder depending on the Content-Type header. If you are sure what you are binding, you can use BindWith.
You can also specify that specific fields are required. If a field is decorated with `binding:"required"` and has a empty value when binding, the current request will fail with an error.
```go
// Binding from JSON
type LoginJSON struct {
User string `json:"user" binding:"required"`
Password string `json:"password" binding:"required"`
}
// Binding from form values
type LoginForm struct {
User string `form:"user" binding:"required"`
Password string `form:"password" binding:"required"`
}
func main() {
r := gin.Default()
// Example for binding JSON ({"user": "manu", "password": "123"})
r.POST("/login", func(c *gin.Context) {
var json LoginJSON
// If EnsureBody returns false, it will write automatically the error
// in the HTTP stream and return a 400 error. If you want custom error
// handling you should use: c.ParseBody(interface{}) error
if c.EnsureBody(&json) {
c.Bind(&json) // This will infer what binder to use depending on the content-type header.
if json.User == "manu" && json.Password == "123" {
c.JSON(200, gin.H{"status": "you are logged in"})
} else {
c.JSON(401, gin.H{"status": "unauthorized"})
}
})
// Example for binding a HTLM form (user=manu&password=123)
r.POST("/login", func(c *gin.Context) {
var form LoginForm
c.BindWith(&form, binding.Form) // You can also specify which binder to use. We support binding.Form, binding.JSON and binding.XML.
if form.User == "manu" && form.Password == "123" {
c.JSON(200, gin.H{"status": "you are logged in"})
} else {
c.JSON(401, gin.H{"status": "unauthorized"})
}
})