Get Started With Templates

In the first step you have learned how to embed Go programs. In this second step you will learn how to execute Scriggo templates in your applications.

It requires 10 minutes to be completed.

Before you start using Scriggo in a Go application you must download and install Go.

Execute templates in your application

Scriggo, in templates, supports inheritance, macros, partials, imports and contextual autoescaping but most of all it uses the Go language as the template scripting language.

Scriggo templates can be written with plain text, HTML, Markdown, CSS, JavaScript and JSON.

Open a terminal and create a new directory for the application:

$ mkdir hello-template
$ cd hello-template

Initialize a Go module in the previous created directory:

$ go mod init hello-template

Get the scriggo package:

$ go get github.com/open2b/scriggo

Create a file main.go with the following source code:

// Build and run a Scriggo template.
package main

import (
    "github.com/open2b/scriggo"
    "log"
    "os"
)

func main() {

    // Content of the template file to run.
    content := []byte(`
    <!DOCTYPE html>
    <html>
    <head>Hello</head> 
    <body>
        {% who := "World" %}
        Hello, {{ who }}!
    </body>
    </html>
    `)

    // Create a file system with the file of the template to run.
    fsys := scriggo.Files{"index.html": content}

    // Build the template.
    template, err := scriggo.BuildTemplate(fsys, "index.html", nil)
    if err != nil {
        log.Fatal(err)
    }
 
    // Run the template and print it to the standard output.
    err = template.Run(os.Stdout, nil, nil)
    if err != nil {
        log.Fatal(err)
    }

}

Build the application directly from the hello-template directory.

$ go build

Execute the application:

$ ./hello-template

    <!DOCTYPE html>
    <html>
    <head>Hello</head> 
    <body>
        Hello, World!
    </body>
    </html>

Globals

A template executed by Scriggo, apart from the Go builtins, can only use explicitly passed globals with the Globals option and can only import packages whose importer has been passed with the Packages option.

Scriggo provides some useful globals, in the github.com/open2b/scriggo/builtin package, that can be used in templates.

Replace the content of the main.go file with the following:

// Build and run a Scriggo template.
package main

import (
    "github.com/open2b/scriggo"
    "github.com/open2b/scriggo/builtin"
    "github.com/open2b/scriggo/native"
    "log"
    "os"
)

func main() {

    // Content of the template file to run.
    content := []byte(`
    <!DOCTYPE html>
    <html>
    <head>Hello</head> 
    <body>
        {% who := "World" %}
        Hello, {{ replace(who, "World", "世界", 1) }}!
    </body>
    </html>
    `)

    // Create a file system with the file of the template to run.
    fsys := scriggo.Files{"index.html": content}

    // Allow to use the "replace" built-in in the template file.
    globals := native.Declarations{
        "replace": builtin.Replace,
    }
    opts := scriggo.BuildOptions{Globals: globals}

    // Build the template.
    template, err := scriggo.BuildTemplate(fsys, "index.html", &opts)
    if err != nil {
        log.Fatal(err)
    }
 
    // Run the template and print it to the standard output.
    err = template.Run(os.Stdout, nil, nil)
    if err != nil {
        log.Fatal(err)
    }

}

Rebuild the application directly from the hello-template directory.

$ go build

Execute the application:

$ ./hello-template

    <!DOCTYPE html>
    <html>
    <head>Hello</head> 
    <body>
        Hello, 世界!
    </body>
    </html>

Use your globals

The following code defines a global function called "printHello" and passes it to the BuildTemplate function.

globals := native.Declarations{
    "printHello": func (who string) string { return fmt.Sprintf("Hello, %s!", who) },
}
opts := &scriggo.BuildOptions{Globals: globals}
template, err := scriggo.BuildTemplate(fsys, "index.html", opts)

Globals can be functions, variables, constants, types and even packages.

Continue to learn

You can continue to learn with these resources: