# Templates: Introduction to HTML Templates

There are many scenarios in which we want to create templates suitable for web applications. It is possible to write HTML templates dynamically using the `text/template` package, however using `html/template` makes your HTML templates injection-safe as it automatically escapes HTML characters that are found in the input. For example, if the input contains characters such as `<`, `>`, or `&`, the `html/template` package will convert these characters to `&lt;`, `&gt;`, and `&amp;` respectively so that they don’t interfere with the overall HTML structure. In most cases, the input for templates come from unknown sources, and so `html/template` should be used to produce HTML templates.

We begin with the same code in `main.go` as in my [previous blog post](https://alissalozhkin.hashnode.dev/templates-using-actions-functions-and-custom-functions):

```go
package main

import (
	"html/template"
	"os"
	"strings"
)

type Person struct {
	Name       string
	Age        int
	Employed   bool
	Occupation string
	Interests  []string
}

func sub(i int) int {
	return i - 1
}

func main() {
	people := []Person{
		{
			Name:       "Bob",
			Age:        42,
			Employed:   true,
			Occupation: "Doctor",
			Interests:  []string{"Reading", "Swimming"},
		},
		{
			Name:       "Jessica",
			Age:        22,
			Employed:   false,
			Occupation: "",
			Interests:  []string{"Piano", "Baking"},
		},
		{
			Name:       "Ben",
			Age:        23,
			Employed:   false,
			Occupation: "",
			Interests:  []string{"Music", "Running"},
		},
	}
	tmplFile := "demo_html.tmpl"
	fMap := template.FuncMap{
		"sub":  sub,
		"join": strings.Join,
	}
	tmpl, err := template.New(tmplFile).Funcs(fMap).ParseFiles(tmplFile)
	if err != nil {
		panic(err)
	}
	file, err := os.Create("layout.html")
	if err != nil {
		panic(err)
	}
	err = tmpl.Execute(file, people)
	if err != nil {
		panic(err)
	}
}
```

Note that I created a new template file `demo_html.tmpl`. Also, instead of outputting the template to the terminal, I chose to write it to a file called `layout.html`.

In `demo_html.tmpl`, we write the following code:

```go
{{ range . }}

<h1> Name: {{.Name}} </h1>
<ul>
<li> Age: {{.Age}} </li>
<li> Occupation: {{ if .Employed }}{{ .Occupation }}{{ else }}Unemployed{{end}} </li>
<li> Interests: {{ join .Interests " & " }} </li>
</ul>

{{ end }}
```

After saving this file and running `go run main.go`, opening `layout.html` reveals the following:

```go
<h1> Name: Bob </h1>
<ul>
<li> Age: 42 </li>
<li> Occupation: Doctor </li>
<li> Interests: Reading &amp; Swimming </li>
</ul>


<h1> Name: Jessica </h1>
<ul>
<li> Age: 22 </li>
<li> Occupation: Unemployed </li>
<li> Interests: Piano &amp; Baking </li>
</ul>


<h1> Name: Ben </h1>
<ul>
<li> Age: 23 </li>
<li> Occupation: Unemployed </li>
<li> Interests: Music &amp; Running </li>
</ul>
```

You can see in `layout.html` that the `&` characters are escaped by `html/template` package. Running `layout.html` will give the following on a web browser:

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1753993915982/685e5384-0486-43ab-b44a-ecf3b181aeba.png align="center")