form

Documentation

Overview

Package form implements decoding HTTP form data and file upload as Golang struct.

Index

• Variables
• func Unpack(r *http.Request, ptr interface{}) error
• func UnpackWithOption(r *http.Request, ptr interface{}, option Option) error
• type Option

Examples

• Unpack
• UnpackWithOption

Variables

var FieldTag = "json"

FieldTag is the default tag key.

var MultipartMaxMemory int64 = 10 * 1024

MultipartMaxMemory the up to a total of maxMemory bytes of its file parts are stored in memory. See http.Request.ParseMultipartForm for more information. Default to 10M.

Functions

func Unpack

func Unpack(r *http.Request, ptr interface{}) error

Unpack populates the fields of the struct pointed to by ptr from the HTTP request body in r.

Example

package main

import (
	"fmt"
	"net/http"

	"github.com/longkai/encoding/form"
)

func main() {
	form.FieldTag = "http" // the Default key is `json`, you can change it.
	// Populate a request, grabbing one via ServerHTTP in server side usually.
	r, err := http.NewRequest(http.MethodGet, "https://google.com/search?q=golang&int=1&float=3.14&bool=true&array=1&array=2&array=3&camelCase=123", nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	var params struct {
		Q         string  `http:"q"`
		Int       string  `http:"int"`
		Float     float64 `http:"float"`
		Bool      bool    `http:"bool"`
		Array     []int   `http:"array"`
		CamelCase int     // camelCase=xxx
	}
	params.Q = "hello" // Set default value for fields.
	if err := form.UnpackWithOption(r, &params, form.Query); err != nil {
		fmt.Println(err)
		return
	}
	fmt.Printf("%+v\n", params)
}

Output:

{Q:golang Int:1 Float:3.14 Bool:true Array:[1 2 3] CamelCase:123}

func UnpackWithOption

func UnpackWithOption(r *http.Request, ptr interface{}, option Option) error

UnpackWithOption populates the fields of the struct pointed to by ptr from the HTTP request parameters in r with the given unpack option.

Example

package main

import (
	"fmt"
	"mime/multipart"
	"net/http"
	"strings"

	"github.com/longkai/encoding/form"
)

func main() {
	form.FieldTag = "json"
	fileUploadBody := `------WebKitFormBoundarykhWusB7Rx4ybHQtA
Content-Disposition: form-data; name="hello"

world
------WebKitFormBoundarykhWusB7Rx4ybHQtA
Content-Disposition: form-data; name="file"; filename="hello.txt"
Content-Type: text/plain

hello, world

------WebKitFormBoundarykhWusB7Rx4ybHQtA--`

	// Simulate a multipart fileupload request.
	r, err := http.NewRequest(http.MethodPost, "https://google.com/upload?q=golang", strings.NewReader(fileUploadBody))
	if err != nil {
		fmt.Println(err)
		return
	}
	r.Header.Set("Content-Type", "multipart/form-data; boundary=----WebKitFormBoundarykhWusB7Rx4ybHQtA")

	var params struct {
		Val  string                `json:"hello"`
		File *multipart.FileHeader `json:"file"`
		// Other key/val, file or file array.
	}
	if err := form.UnpackWithOption(r, &params, form.Multipart); err != nil {
		fmt.Println(err)
		return
	}
	fmt.Printf("Val: %v, file name: %v, file size: %d", params.Val, params.File.Filename, params.File.Size)
}

Output:

Val: world, file name: hello.txt, file size: 13

Types

type Option

type Option int

Option pack option.

const (
	// Body only parses the request body.
	Body Option = iota
	// Query only parses the request URL query.
	Query
	// Multipart like Body but counts multipart files in.
	Multipart
	// Mixed mixes the request body and URL query, note the Query has higher priority if same key found.
	// It's existed for compatability only.
	Mixed
	// MixedMultipart mixes Multipart and Query, Query has higher priority.
	// It's existed for compatability only.
	MixedMultipart
)