github.com/theplant/htmlgo

v1.0.3

Source

Version published: 4 years ago

Created: 5 years ago

Source

htmlgo

Type safe and modularize way to generate html on server side. Download the package with go get -v github.com/theplant/htmlgo and import the package with . gives you simpler code:

import (
	. "github.com/theplant/htmlgo"
)

also checkout full API documentation at: https://godoc.org/github.com/theplant/htmlgo

Create a simple div, Text will be escaped by html

	banner := "We write html in Go"
	comp := Div(
	    Text("123<h1>"),
	    Textf("Hello, %s", banner),
	    Br(),
	)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <div>123&lt;h1&gt;Hello, We write html in Go
	// <br></div>

Create a full html page

	comp := HTML(
	    Head(
	        Meta().Charset("utf8"),
	        Title("My test page"),
	    ),
	    Body(
	        Img("images/firefox-icon.png").Alt("My test image"),
	    ),
	)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <!DOCTYPE html>
	//
	// <html>
	// <head>
	// <meta charset='utf8'></meta>
	//
	// <title>My test page</title>
	// </head>
	//
	// <body>
	// <img src='images/firefox-icon.png' alt='My test image'></img>
	// </body>
	// </html>

Use RawHTML and Component

	userProfile := func(username string, avatarURL string) HTMLComponent {
	    return ComponentFunc(func(ctx context.Context) (r []byte, err error) {
	        return Div(
	            H1(username).Class("profileName"),
	            Img(avatarURL).Class("profileImage"),
	            RawHTML("<svg>complicated svg</svg>\n"),
	        ).Class("userProfile").MarshalHTML(ctx)
	    })
	}
	
	comp := Ul(
	    Li(
	        userProfile("felix<h1>", "http://image.com/img1.png"),
	    ),
	    Li(
	        userProfile("john", "http://image.com/img2.png"),
	    ),
	)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <ul>
	// <li>
	// <div class='userProfile'>
	// <h1 class='profileName'>felix&lt;h1&gt;</h1>
	//
	// <img src='http://image.com/img1.png' class='profileImage'></img>
	// <svg>complicated svg</svg>
	// </div>
	// </li>
	//
	// <li>
	// <div class='userProfile'>
	// <h1 class='profileName'>john</h1>
	//
	// <img src='http://image.com/img2.png' class='profileImage'></img>
	// <svg>complicated svg</svg>
	// </div>
	// </li>
	// </ul>

More complicated customized component

	/*
	    Define MySelect as follows:
	
	    type MySelectBuilder struct {
	        options  [][]string
	        selected string
	    }
	
	    func MySelect() *MySelectBuilder {
	        return &MySelectBuilder{}
	    }
	
	    func (b *MySelectBuilder) Options(opts [][]string) (r *MySelectBuilder) {
	        b.options = opts
	        return b
	    }
	
	    func (b *MySelectBuilder) Selected(selected string) (r *MySelectBuilder) {
	        b.selected = selected
	        return b
	    }
	
	    func (b *MySelectBuilder) MarshalHTML(ctx context.Context) (r []byte, err error) {
	        opts := []HTMLComponent{}
	        for _, op := range b.options {
	            var opt HTMLComponent
	            if op[0] == b.selected {
	                opt = Option(op[1]).Value(op[0]).Attr("selected", "true")
	            } else {
	                opt = Option(op[1]).Value(op[0])
	            }
	            opts = append(opts, opt)
	        }
	        return Select(opts...).MarshalHTML(ctx)
	    }
	*/
	
	comp := MySelect().Options([][]string{
	    {"1", "label 1"},
	    {"2", "label 2"},
	    {"3", "label 3"},
	}).Selected("2")
	
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <select>
	// <option value='1'>label 1</option>
	//
	// <option value='2' selected='true'>label 2</option>
	//
	// <option value='3'>label 3</option>
	// </select>

Write a little bit of JavaScript and stylesheet

	comp := Div(
	    Button("Hello").Id("hello"),
	    Style(`
	.container {
	    background-color: red;
	}
	`),
	
	    Script(`
	var b = document.getElementById("hello")
	b.onclick = function(e){
	    alert("Hello");
	}
	`),
	).Class("container")
	
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <div class='container'>
	// <button id='hello'>Hello</button>
	//
	// <style type='text/css'>
	// 	.container {
	// 		background-color: red;
	// 	}
	// </style>
	//
	// <script type='text/javascript'>
	// 	var b = document.getElementById("hello")
	// 	b.onclick = function(e){
	// 		alert("Hello");
	// 	}
	// </script>
	// </div>

An example about how to integrate into http.Handler, and how to do layout, and how to use context.

	type User struct {
	    Name string
	}
	
	userStatus := func() HTMLComponent {
	    return ComponentFunc(func(ctx context.Context) (r []byte, err error) {
	
	        if currentUser, ok := ctx.Value("currentUser").(*User); ok {
	            return Div(
	                Text(currentUser.Name),
	            ).Class("username").MarshalHTML(ctx)
	        }
	
	        return Div(Text("Login")).Class("login").MarshalHTML(ctx)
	    })
	}
	
	myHeader := func() HTMLComponent {
	    return Div(
	        Text("header"),
	        userStatus(),
	    ).Class("header")
	}
	myFooter := func() HTMLComponent {
	    return Div(Text("footer")).Class("footer")
	}
	
	layout := func(in HTMLComponent) (out HTMLComponent) {
	    out = HTML(
	        Head(
	            Meta().Charset("utf8"),
	        ),
	        Body(
	            myHeader(),
	            in,
	            myFooter(),
	        ),
	    )
	    return
	}
	
	getLoginUserFromCookie := func(r *http.Request) *User {
	    return &User{Name: "felix"}
	}
	
	homeHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	    user := getLoginUserFromCookie(r)
	    ctx := context.WithValue(context.TODO(), "currentUser", user)
	
	    root := Div(
	        Text("This is my home page"),
	    )
	
	    Fprint(w, layout(root), ctx)
	})
	
	w := httptest.NewRecorder()
	r := httptest.NewRequest("GET", "/", nil)
	homeHandler.ServeHTTP(w, r)
	
	fmt.Println(w.Body.String())
	
	//Output:
	// <!DOCTYPE html>
	//
	// <html>
	// <head>
	// <meta charset='utf8'></meta>
	// </head>
	//
	// <body>
	// <div class='header'>header
	// <div class='username'>felix</div>
	// </div>
	//
	// <div>This is my home page</div>
	//
	// <div class='footer'>footer</div>
	// </body>
	// </html>

An example show how to set different type of attributes

	type MoreData struct {
	    Name  string
	    Count int
	}
	comp := Div(
	    Input("username").
	        Type("checkbox").
	        Attr("checked", true).
	        Attr("more-data", &MoreData{Name: "felix", Count: 100}).
	        Attr("max-length", 10),
	    Input("username2").
	        Type("checkbox").
	        Attr("checked", false),
	)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <div>
	// <input name='username' type='checkbox' checked more-data='{"Name":"felix","Count":100}' max-length='10'></input>
	//
	// <input name='username2' type='checkbox'></input>
	// </div>

An example show how to set styles

	comp := Div().
	    StyleIf("background-color:red; border:1px solid red;", true).
	    StyleIf("color:blue", true)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <div style='background-color:red; border:1px solid red; color:blue;'></div>

An example to use If, Iff is for body to passed in as an func for the body depends on if condition not to be nil, If is for directly passed in HTMLComponent

	type Person struct {
	    Age int
	}
	var p *Person
	
	name := "Leon"
	comp := Div(
	    Iff(p != nil && p.Age > 18, func() HTMLComponent {
	        return Div().Text(name + ": Age > 18")
	    }).ElseIf(p == nil, func() HTMLComponent {
	        return Div().Text("No person named " + name)
	    }).Else(func() HTMLComponent {
	        return Div().Text(name + ":Age <= 18")
	    }),
	)
	Fprint(os.Stdout, comp, context.TODO())
	//Output:
	// <div>
	// <div>No person named Leon</div>
	// </div>

FAQs

What is github.com/theplant/htmlgo?

Package last updated on 18 Sep 2021

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