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.TplNames = "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.TplNames = "view.tpl"
}

NewController

type NewController struct {
    beego.Controller
}

func (this *NewController) Get() {
    this.Layout = "layout.tpl"
    this.TplNames = "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.TplNames = "new.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 := GetBlog(id int)
    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>