Go Web 编程

13.5 实现博客的增删改

前面介绍了beego框架实现的整体构思以及部分实现的伪代码,这小节介绍通过beego建立一个博客系统,包括博客浏览、添加、修改、删除等操作。

博客目录

博客目录如下所示:

.
├── controllers
│   ├── delete.go
│   ├── edit.go
│   ├── index.go
│   ├── new.go
│   └── view.go
├── main.go
├── models
│   └── model.go
└── views
    ├── edit.tpl
    ├── index.tpl
    ├── layout.tpl
    ├── new.tpl
    └── view.tpl

博客路由

博客主要的路由规则如下所示:

//显示博客首页
beego.Router("/", &controllers.IndexController{})
//查看博客详细信息
beego.Router("/view/:id([0-9]+)", &controllers.ViewController{})
//新建博客博文
beego.Router("/new", &controllers.NewController{})
//删除博文
beego.Router("/delete/:id([0-9]+)", &controllers.DeleteController{})
//编辑博文
beego.Router("/edit/:id([0-9]+)", &controllers.EditController{})

数据库结构

数据库设计最简单的博客信息

CREATE TABLE entries (
    id INT AUTO_INCREMENT,
    title TEXT,
    content TEXT,
    created DATETIME,
    primary key (id)
);

控制器

IndexController:

type IndexController struct {
	beego.Controller
}

func (this *IndexController) Get() {
	this.Data["blogs"] = models.GetAll()
	this.Layout = "layout.tpl"
	this.TplName = "index.tpl"
}

ViewController:

type ViewController struct {
	beego.Controller
}

func (this *ViewController) Get() {
	id, _ := strconv.Atoi(this.Ctx.Input.Params()[":id"])
	this.Data["Post"] = models.GetBlog(id)
	this.Layout = "layout.tpl"
	this.TplName = "view.tpl"
}

NewController

type NewController struct {
	beego.Controller
}

func (this *NewController) Get() {
	this.Layout = "layout.tpl"
	this.TplName = "new.tpl"
}

func (this *NewController) Post() {
	inputs := this.Input()
	var blog models.Blog
	blog.Title = inputs.Get("title")
	blog.Content = inputs.Get("content")
	blog.Created = time.Now()
	models.SaveBlog(blog)
	this.Ctx.Redirect(302, "/")
}		

EditController

type EditController struct {
	beego.Controller
}

func (this *EditController) Get() {
	id, _ := strconv.Atoi(this.Ctx.Input.Params()[":id"])
	this.Data["Post"] = models.GetBlog(id)
	this.Layout = "layout.tpl"
	this.TplName = "edit.tpl"
}

func (this *EditController) Post() {
	inputs := this.Input()
	var blog models.Blog
	blog.Id, _ = strconv.Atoi(inputs.Get("id"))
	blog.Title = inputs.Get("title")
	blog.Content = inputs.Get("content")
	blog.Created = time.Now()
	models.SaveBlog(blog)
	this.Ctx.Redirect(302, "/")
}

DeleteController

type DeleteController struct {
	beego.Controller
}

func (this *DeleteController) Get() {
	id, _ := strconv.Atoi(this.Ctx.Input.Params()[":id"])
	blog := models.GetBlog(id)
	this.Data["Post"] = blog
	models.DelBlog(blog)
	this.Ctx.Redirect(302, "/")
}

model层

package models

import (
	"database/sql"
	"github.com/astaxie/beedb"
	_ "github.com/ziutek/mymysql/godrv"
	"time"
)

type Blog struct {
	Id      int `PK`
	Title   string
	Content string
	Created time.Time
}

func GetLink() beedb.Model {
	db, err := sql.Open("mymysql", "blog/astaxie/123456")
	if err != nil {
		panic(err)
	}
	orm := beedb.New(db)
	return orm
}

func GetAll() (blogs []Blog) {
	db := GetLink()
	db.FindAll(&blogs)
	return
}

func GetBlog(id int) (blog Blog) {
	db := GetLink()
	db.Where("id=?", id).Find(&blog)
	return
}

func SaveBlog(blog Blog) (bg Blog) {
	db := GetLink()
	db.Save(&blog)
	return bg
}

func DelBlog(blog Blog) {
	db := GetLink()
	db.Delete(&blog)
	return
}

view层

layout.tpl

<html>
<head>
    <title>My Blog</title>
    <style>
        #menu {
            width: 200px;
            float: right;
        }
    </style>
</head>
<body>

<ul id="menu">
    <li><a href="/">Home</a></li>
    <li><a href="/new">New Post</a></li>
</ul>

{{.LayoutContent}}

</body>
</html>

index.tpl

<h1>Blog posts</h1>

<ul>
{{range .blogs}}
    <li>
        <a href="/view/{{.Id}}">{{.Title}}</a>
        from {{.Created}}
        <a href="/edit/{{.Id}}">Edit</a>
        <a href="/delete/{{.Id}}">Delete</a>
    </li>
{{end}}
</ul>

view.tpl

<h1>{{.Post.Title}}</h1>
{{.Post.Created}}<br/>

{{.Post.Content}}				

new.tpl

<h1>New Blog Post</h1>
<form action="" method="post">
标题:<input type="text" name="title"><br>
内容:<textarea name="content" colspan="3" rowspan="10"></textarea>
<input type="submit">
</form>

edit.tpl

<h1>Edit {{.Post.Title}}</h1>

<h1>New Blog Post</h1>
<form action="" method="post">
标题:<input type="text" name="title" value="{{.Post.Title}}"><br>
内容:<textarea name="content" colspan="3" rowspan="10">{{.Post.Content}}</textarea>
<input type="hidden" name="id" value="{{.Post.Id}}">
<input type="submit">
</form>