Beego development blog system learning (II)

1 Article writing function development

1） Database design

util add to article Table operations ：

// Create an article table 
func CreateTableWithArticle(){
	sql:=`create table if not exists article(
		id int(4) primary key auto_increment not null,
		title varchar(30),
		author varchar(20),
		tags varchar(30),
		short varchar(255),
		content longtext,
		createtime int(10)
		);`
	ModifyDB(sql)
}

2）model layer

3） Control layer

 4） The routing layer
beego.Router("/article/add", &controllers.AddArticleController{})

5） View layer

6）js

  Take a look at the preliminary results ：

2 Article display

2.1 Home page display

1）home_controller.go file , stay Get() In the method , Check all the articles first , And display it on the page .

func (this *HomeController) Get() {
	page, _ := this.GetInt("page")
	if page <= 0 {
		page = 1
	}
	var artList []models.Article
	artList, _ = models.FindArticleWithPage(page)
	this.Data["PageCode"] = 1
	this.Data["HasFooter"] = true
	fmt.Println("IsLogin:", this.IsLogin, this.Loginuser)
	this.Data["Content"] = models.MakeHomeBlocks(artList, this.IsLogin)
	this.TplName = "home.html"
}

2）article_model.go In file , Add the query of the article

// Query the article according to the page number 
func FindArticleWithPage(page int) ([]Article, error) {
	// Get the number of articles per page from the configuration file 
	num, _ := beego.AppConfig.Int("articleListPageNum")
	page--
	fmt.Println("---------->page", page)
	return QueryArticleWithPage(page, num)
}

/**
 Paging query database 
limit Paging query statement ,
	 grammar ：limit m,n

	m Represents how many digits to start with , And id Value independent 
	n Represents how many pieces of data are obtained 

 Be careful limit What's ahead where
 */
func QueryArticleWithPage(page, num int) ([]Article, error) {
	sql := fmt.Sprintf("limit %d,%d", page*num, num)
	return QueryArticlesWithCon(sql)
}

func QueryArticlesWithCon(sql string) ([]Article, error) {
	sql = "select id,title,tags,short,content,author,createtime from article " + sql
	rows, err := utils.QueryDB(sql)
	if err != nil {
		return nil, err
	}
	var artList []Article
	for rows.Next() {
		id := 0
		title := ""
		tags := ""
		short := ""
		content := ""
		author := ""
		var createtime int64
		createtime = 0
		rows.Scan(&id, &title, &tags, &short, &content, &author, &createtime)
		art := Article{id, title, tags, short, content, author, createtime}
		artList = append(artList, art)
	}
	return artList, nil
}

3） establish home_module.go Show the articles on the home page

//---------- Home page display content ---------
func MakeHomeBlocks(articles []Article, isLogin bool) template.HTML {
	htmlHome := ""
	for _, art := range articles {
		// Will database model Required to convert to the homepage template model
		homeParam := HomeBlockParam{}
		homeParam.Id = art.Id
		homeParam.Title = art.Title
		homeParam.Tags = createTagsLinks(art.Tags)
		fmt.Println("tag-->", art.Tags)
		homeParam.Short = art.Short
		homeParam.Content = art.Content
		homeParam.Author = art.Author
		var timeLayoutStr = "2006-01-02 15:04:05" 
		homeParam.CreateTime = time.Unix(art.Createtime,0).Format(timeLayoutStr)
		homeParam.Link = "/article/" + strconv.Itoa(art.Id)
		homeParam.UpdateLink = "/article/update?id=" + strconv.Itoa(art.Id)
		homeParam.DeleteLink = "/article/delete?id=" + strconv.Itoa(art.Id)
		homeParam.IsLogin = isLogin

		// Handling variables 
		//ParseFile Parse the file , Used to insert variables 
		t, _ := template.ParseFiles("views/block/home_block.html")
		buffer := bytes.Buffer{}
		// Will be html Replace the two in the file with the data inserted 
		t.Execute(&buffer, homeParam)
		htmlHome += buffer.String()
	}
	return template.HTML(htmlHome)
}

// take tags String into the data structure required by the home page template 
func createTagsLinks(tags string) []TagLink {
	var tagLink [] TagLink
	tagsPamar := strings.Split(tags, "&")
	for _, tag := range tagsPamar {
		tagLink = append(tagLink, TagLink{tag, "/?tag=" + tag})
	}
	return tagLink
}

 4） View layer

stay model Of MakeHomeBlocks() In the method , You need to fill in and format with templates html The page content , So we are views/block Next, create another html page ：home_block.html

5） Effect display  

2.2 Paging display

1）home_module Design

Paging structure object

type HomeFooterPageCode struct {
	HasPre bool
	HasNext bool
	ShowPage string
	PreLink string
	NextLink string
}

//----------- Page turning -----------
//page Is the current number of pages 
func ConfigHomeFooterPageCode(page int) HomeFooterPageCode {
	pageCode := HomeFooterPageCode{}
	// Find the total number of entries 
	num := GetArticleRowsNum()
	// Read the number of entries displayed per page from the configuration file 
	pageRow, _ := beego.AppConfig.Int("articleListPageNum")
	// Calculate the total number of pages 
	allPageNum := (num-1)/pageRow + 1
	pageCode.ShowPage = fmt.Sprintf("%d/%d", page, allPageNum)
	// The current number of pages is less than or equal to 1, Then the button on the previous page cannot be clicked 
	if page <= 1 {
		pageCode.HasPre = false
	} else {
		pageCode.HasPre = true
	}
	// The current number of pages is greater than or equal to the total number of pages , Then the button on the next page cannot be clicked 
	if page >= allPageNum {
		pageCode.HasNext = false
	} else {
		pageCode.HasNext = true
	}
	pageCode.PreLink = "/?page=" + strconv.Itoa(page-1)
	pageCode.NextLink = "/?page=" + strconv.Itoa(page+1)
	return pageCode
}

2）article_model.go In file , Add the method of querying the total amount of data

There is also a question to consider , When adding or deleting articles , The total amount of data will change , So we need to modify the method of adding articles  

 3）home_controller.go

 4)home.html

5) effect

2.3 Show article details

1） Route add

 2）show_article_controller.go

 3）article_model.go In file , Add method , according to id Search article

//---------- Search article -------------
func QueryArticleWithId(id int) Article {
	row := utils.QueryRowDB("select id,title,tags,short,content,author,createtime from article where id=" + strconv.Itoa(id))
	title := ""
	tags := ""
	short := ""
	content := ""
	author := ""
	var createtime int64
	createtime = 0
	row.Scan(&id, &title, &tags, &short, &content, &author, &createtime)
	art := Article{id, title, tags, short, content, author, createtime}
	return art
}

4） stay views Under the table of contents , newly build html pagefile ,show_article.html

2.4 Revise article

1）update_rticle_control.go

/**
 *  Update the controller of the article 
 */
type UpdateArticleController struct {
	BaseController
}

// When accessing /update The path is triggered back Get() Method , The response page is through TplName This property specifies the page returned to the client 
func (this *UpdateArticleController) Get() {
	id, _ := this.GetInt("id")
	fmt.Println(id)

	// obtain id Corresponding article information 
	art := models.QueryArticleWithId(id)

	this.Data["Title"] = art.Title
	this.Data["Tags"] = art.Tags
	this.Data["Short"] = art.Short
	this.Data["Content"] = art.Content
	this.Data["Id"] = art.Id

	this.TplName = "write_article.html"
}

// Revise article 
func (this *UpdateArticleController) Post() {
	id, _ := this.GetInt("id")
	fmt.Println("postid:", id)

	// Get the data transmitted by the browser , Through the form name Property gets value 
	title := this.GetString("title")
	tags := this.GetString("tags")
	short := this.GetString("short")
	content := this.GetString("content")

	// Instantiation model, modify the database 
	art := models.Article{id, title, tags, short, content, "", 0}
	_, err := models.UpdateArticle(art)

	// Return the data to the browser 
	if err == nil {
		this.Data["json"] = map[string]interface{}{"code": 1, "message": " The update is successful "}
	} else {
		this.Data["json"] = map[string]interface{}{"code": 0, "message": " Update failed "}
	}

	this.ServeJSON()
}

2）write_article.html

<div id="main">
    <form id="write-art-form" method="post">
        <div> title </div>
        <input type="text" placeholder=" Please enter a title " name="title" value="{
   {.Title}}">
        <div> label </div>
        <input type="text" placeholder=" Please enter the label " name="tags" value="{
   {.Tags}}">
        <div> brief introduction </div>
        <textarea placeholder=" Please enter the profile " name="short">{
   {.Short}}</textarea>
        <div> Content </div>
        <textarea id="content" placeholder=" Please enter the content " name="content">{
   {.Content}}</textarea>
        <input id="write-article-id" hidden name="id" value="{
   {.Id}}">
        <button type="button" onclick="history.back()"> return </button>
        <button type="submit" id="write-art-submit"> Submit </button>
    </form>
</div>

Modify or add , Actually, it depends on the page id Value , If you are adding, use the default value 0, If it is modified, it is the real value queried from the database , So it needs to be modified js Script files ：

 3）model Layer add modify article database operation

//---------- Modifying data ----------
func UpdateArticle(article Article) (int64, error) {
	// Database operation 
	return utils.ModifyDB("update article set title=?,tags=?,short=?,content=? where id=?",
		article.Title, article.Tags, article.Short, article.Content, article.Id)
}

3 Label development

1） stay article_model.go Query all tags existing in the database in the file

2） establish tags_model.go

 3） establish tags_controller.go

 4） Routing settings

beego.Router("/tags", &controllers.TagsController{})

5） View layer add tags.html

 6）tags Effect display