binding

A powerful fasthttp request parameters binder that supports struct tag expression.

Syntax

The parameter position in HTTP request:

expression	renameable	description
path:"$name" or path:"$name,required"	Yes	URL path parameter
query:"$name" or query:"$name,required"	Yes	URL query parameter
raw_body:"" or raw_body:"required"	Yes	The raw bytes of body
form:"$name" or form:"$name,required"	Yes	The field in body, support: application/x-www-form-urlencoded, multipart/form-data
protobuf:"...(raw syntax)"	No	The field in body, support: application/x-protobuf
json:"$name" or json:"$name,required"	No	The field in body, support: application/json
header:"$name" or header:"$name,required"	Yes	Header parameter
cookie:"$name" or cookie:"$name,required"	Yes	Cookie parameter
default:"$value"	Yes	Default parameter
vd:"...(tagexpr validator syntax)"	Yes	The tagexpr expression of validator

NOTE:

• "$name" is variable placeholder
• If "$name" is empty, use the name of field
• If "$name" is -, omit the field
• Expression required or req indicates that the parameter is required
• default:"$value" defines the default value for fallback when no binding is successful
• If no position is tagged, try bind parameters from the body when the request has body,
  otherwise try bind from the URL query
• When there are multiple tags or no tags, the order in which to try to bind is:
  1. path
  2. form
  3. query
  4. cookie
  5. header
  6. protobuf
  7. json
  8. default

Type Unmarshalor

TimeRFC3339-binding function is registered by default.

Register your own binding function for the specified type, e.g.:

MustRegTypeUnmarshal(reflect.TypeOf(time.Time{}), func(v string, emptyAsZero bool) (reflect.Value, error) {
	if v == "" && emptyAsZero {
		return reflect.ValueOf(time.Time{}), nil
	}
	t, err := time.Parse(time.RFC3339, v)
	if err != nil {
		return reflect.Value{}, err
	}
	return reflect.ValueOf(t), nil
})