RESTful-API-with-Go-and-Gin

ref:

• Tutorial: Developing a RESTful API with Go and Gin
• Gin Web Framework package documentation
• gin-gonic/gin

---

Import package and Create the data

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

//struct
type album struct {
	ID     string  `json:"id"`
	Title  string  `json:"title"`
	Artist string  `json:"artist"`
	Price  float64 `json:"price"`
}

// slice
var albums = []album{
	{ID: "1", Title: "Blue Train", Artist: "John Coltrane", Price: 56.99},
	{ID: "2", Title: "Jeru", Artist: "Gerry Mulligan", Price: 17.99},
	{ID: "3", Title: "Sarah Vaughan and Clifford Brown", Artist: "Sarah Vaughan", Price: 39.99},
}

Write a hanlder to return all items

func getAlbums(c *gin.Context) {
	c.IndentedJSON(http.StatusOK, albums)
}

• Note that you can replace Context.IndentedJSON with a call to Context.JSON to send more compact JSON. In practice, the indented form is much easier to work with when debugging and the size difference is usually small.

Update main function

func main() {
    router := gin.Default()
    router.GET("/albums", getAlbums)

    router.Run("localhost:8080")
}

Test on Postman

Write a handler to return a specific item

func getAlbumByID(c *gin.Context) {
	id := c.Param("id")

	// loop over the list of albums, looking for
	// an album whose ID value matches the parameter.
	for _, a := range albums {
		if a.ID == id {
			c.IndentedJSON(http.StatusOK, a)
			return
		}
	}
	c.IndentedJSON(http.StatusNotFound, gin.H{"message": "album not found"})
}

Update main function

func main() {
	router := gin.Default()
	router.GET("/albums", getAlbums)
	router.GET("/albums/:id", getAlbumByID)

	router.Run("localhost:8080")
}

Test on Postman

Write a handler to add a new item

func postAlbums(c *gin.Context) {
	var newAlbum album

	//Call BindJSON to bind the received JSON to new album.
	if err := c.BindJSON(&newAlbum); err != nil {
		return
	}
	
	// Add the new album to the slice
	albums = append(albums, newAlbum)
	c.IndentedJSON(http.StatusCreated, newAlbum)
}

• Bindings are used to serialize JSON, XML, path parameters, form data, etc. to structs and maps

Update main function

func main() {
	router := gin.Default()
	router.GET("/albums", getAlbums)
	router.GET("/albums/:id", getAlbumByID)
	router.POST("/albums", postAlbums)

	router.Run("localhost:8080")
}

Test on Postman