httpin

HTTP Input for Go

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BEFORE (use functions provided by net/http lib)	AFTER (use httpin to extract input parameters from HTTP request)
func ListUsers(rw http.ResponseWriter, r *http.Request) { page, err := strconv.ParseInt(r.FormValue("page"), 10, 64) if err != nil { // ... invalid page return } perPage, err := strconv.ParseInt(r.FormValue("per_page"), 10, 64) if err != nil { // ... invalid per_page return } isVip, _ := strconv.ParseBool(r.FormValue("is_vip")) // do sth. }	type ListUsersInput struct { Page int `in:"form=page"` PerPage int `in:"form=per_page"` IsVip bool `in:"form=is_vip"` } func ListUsers(rw http.ResponseWriter, r *http.Request) { interfaceInput, err := httpin.New(ListUsersInput{}).Decode(r) if err != nil { // err can be *httpin.InvalidField return } input := interfaceInput.(*ListUsersInput) // do sth. }

Features

• Decode from HTTP query, i.e. http.Request.Form
• Decode from HTTP headers, e.g. http.Request.Header
• Builtin decoders for basic types, e.g. bool, int, int64, float32, time.Time, ... full list
• Decode one field by inspecting multiple keys one by one in the same source
• Decode one field from multiple sources, e.g. both query and headers
• Customize decoders for user defined types
• Define input struct with embedded struct fields
• Tag one field as required
• Builtin encoders for basic types
• Customize encoders for user defined types

Sample User Defined Input Structs

type Authorization struct {
	// Decode from multiple sources, the former with higher priority
	Token string `in:"form=access_token,header=x-api-token"`
}

type Pagination struct {
	Page int `in:"form=page"`

	// Decode from multiple keys in the same source, the former with higher priority
	PerPage int `in:"form=per_page,page_size"`
}

type ListUsersInput struct {
	Gender   string `in:"form=gender"`
	AgeRange []int  `in:"form=age_range"`
	IsMember bool   `in:"form=is_member"`

	Pagination    // Embedded field works
	Authorization // Embedded field works
}

Advanced - Use Middleware

First, set up the middleware for your handlers. We recommend using alice to chain your HTTP middleware functions.

func init() {
	mux.Handle("/users", alice.New(
		httpin.NewInput(ListUsersInput{}),
	).ThenFunc(ListUsers)).Methods("GET")
}

Second, fetch your input with only one line of code.

func ListUsers(rw http.ResponseWriter, r *http.Request) {
	input := r.Context().Value(httpin.Input).(*UserQuery)
	// do sth.
}