render

Render

Easily rendering JSON, XML, binary data, and HTML templates responses

Usage

It can be used with pretty much any web framework providing you can access the http.ResponseWriter from your handler. The rendering functions simply wraps Go's existing functionality for marshaling and rendering data.

package main

import (
	"encoding/xml"
	"net/http"

	"github.com/ifreddyrondon/bastion"
	"github.com/ifreddyrondon/bastion/render"
)

type ExampleXML struct {
	XMLName xml.Name `xml:"example"`
	One     string   `xml:"one,attr"`
	Two     string   `xml:"two,attr"`
}

func main() {
	app := bastion.New()

	app.Get("/data", func(w http.ResponseWriter, req *http.Request) {
		render.Data.Response(w, http.StatusOK, []byte("Some binary data here."))
	})

	app.Get("/text", func(w http.ResponseWriter, req *http.Request) {
		render.Text.Response(w, http.StatusOK, "Plain text here")
	})

	app.Get("/html", func(w http.ResponseWriter, req *http.Request) {
		render.HTML.Response(w, http.StatusOK, "<h1>Hello World</h1>")
	})

	app.Get("/json", func(w http.ResponseWriter, req *http.Request) {
		render.JSON.Response(w, http.StatusOK, map[string]string{"hello": "json"})
	})

	app.Get("/json-ok", func(w http.ResponseWriter, req *http.Request) {
		// with implicit status 200
		render.JSON.Send(w, map[string]string{"hello": "json"})
	})

	app.Get("/xml", func(w http.ResponseWriter, req *http.Request) {
		render.XML.Response(w, http.StatusOK, ExampleXML{One: "hello", Two: "xml"})
	})

	app.Get("/xml-ok", func(w http.ResponseWriter, req *http.Request) {
		// with implicit status 200
		render.XML.Send(w, ExampleXML{One: "hello", Two: "xml"})
	})

	app.Serve()
}

Renderer

// Renderer interface for managing response payloads.
type Renderer interface {
	// Response encoded responses in the ResponseWriter with the HTTP status code.
	Response(w http.ResponseWriter, code int, response interface{})
}

Implementations:

• render.Data response []byte with application/octet-stream Content-Type.
• render.Text response strings with text/plain Content-Type.
• render.HTML response strings with text/html Content-Type.
• render.JSON response strings with application/json Content-Type.
• render.XML response strings with application/xml Content-Type.

APIRenderer

APIRenderer are convenient methods for api responses.

// APIRenderer interface for managing API response payloads.
type APIRenderer interface {
	Renderer
	OKRenderer
	ClientErrRenderer
	ServerErrRenderer
}

// OKRenderer interface for managing success API response payloads.
type OKRenderer interface {
	Send(w http.ResponseWriter, response interface{})
	Created(w http.ResponseWriter, response interface{})
	NoContent(w http.ResponseWriter)
}

// ClientErrRenderer interface for managing API responses when client error.
type ClientErrRenderer interface {
	BadRequest(w http.ResponseWriter, err error)
	NotFound(w http.ResponseWriter, err error)
	MethodNotAllowed(w http.ResponseWriter, err error)
}

// ServerErrRenderer interface for managing API responses when server error.
type ServerErrRenderer interface {
	InternalServerError(w http.ResponseWriter, err error)
}

Implementations:

• render.JSON response strings with text/html Content-Type.
• render.XML response strings with text/html Content-Type.

package main

import (
	"net/http"
	"errors"

	"github.com/ifreddyrondon/bastion"
	"github.com/ifreddyrondon/bastion/render"
)

type address struct {
	Address string  `json:"address"`
	Lat     float64 `json:"lat"`
	Lng     float64 `json:"lng"`
}

func h201(w http.ResponseWriter, r *http.Request) {
	a := address{"test address", 1, 1}
	render.JSON.Created(w, a)
}

func h400(w http.ResponseWriter, r *http.Request) {
	e := errors.New("test")
	render.JSON.BadRequest(w, e)
}

func h500(w http.ResponseWriter, r *http.Request) {
	e := errors.New("test")
	render.JSON.InternalServerError(w, e)
}

func main() {
	app := bastion.New()
	app.Get("/201", h201)
	app.Get("/400", h400)
	app.Get("/500", h500)
	app.Serve()
}

With Options:

package main

import (
	"encoding/xml"
	"net/http"

	"github.com/ifreddyrondon/bastion"
	"github.com/ifreddyrondon/bastion/render"
)

type ExampleXML struct {
	XMLName xml.Name `xml:"example"`
	One     string   `xml:"one,attr"`
	Two     string   `xml:"two,attr"`
}

func jsonHandler(w http.ResponseWriter, r *http.Request) {
	render.
			NewJSON(render.PrettyPrintJSON()).
			Send(w, map[string]string{"hello": "json with options"})
}

func xmlHandler(w http.ResponseWriter, r *http.Request) {
	render.
			NewXML(render.PrettyPrintXML()).
			Send(w, ExampleXML{One: "hello", Two: "xml"})
}

func main() {
	app := bastion.New()
	app.Get("/json", jsonHandler)
	app.Get("/xml", xmlHandler)
	app.Serve()
}

E.g.