Header and Footer Layouts with Handlebars.NET

 1// MyTemplateProvider.cs
 2
 3    public MyTemplateProvider()
 4    {
 5        _handlebars = Handlebars.Create();
 6
 7        Init(); // Add this
 8    }
 9
10    private void Init()
11    {
12        // Add Header Template
13        _handlebars.RegisterTemplate("Header_Template", @"<strong>MyCompany - {{Title}}</strong>");
14
15        // Add Footer Template
16        _handlebars.RegisterTemplate("Footer_Template", @"<i>MyCompany - Copyright 2023</i>");
17
18        // Register Welcome Mail
19        _handlebars.RegisterTemplate("WelcomeMail_Template",
20            """
21            <div>
22                <h1>{{>Header_Template}}</h1>
23                <div class="body">
24                    <h3>Welcome to our demo {{UserName}}!</h3>
25                <p>Thank you for registering. Have fun!</p>
26                </div>
27                <footer>{{>Footer_Template}}</footer>
28            </div>
29            """);
30   }

1_handlebars.RegisterTemplate("MailLayout", """
2    <div>
3        <h1><strong>MyCompany - {{Title}}</strong></h1>
4        <div class="body">
5            {{> content}}
6        </div>
7        <footer><i>MyCompany - Copyright {{On.Year}}</i></footer>
8    </div>
9    """);

1_handlebars.RegisterTemplate("WelcomeMail_Template",
2    """{{#> MailLayout}}
3            <h3>Welcome to our demo {{UserName}}!</h3>
4            <p>Thank you for registering. Have fun!</p>
5       {{/MailLayout}}
6    """);

 1using HandlebarsDotNet;
 2
 3namespace BenjaminAbt.Samples.HandlebarsNET;
 4
 5internal class Program
 6{
 7    static void Main(string[] args)
 8    {
 9        MyTemplateProvider templateProvider = new();
10
11        List<string> userNames = ["Batman", "Robin"];
12        foreach (var userName in userNames)
13        {
14            string text = templateProvider.RenderWelcomeMail(userName);
15
16            Console.WriteLine($"To: {userName}");
17            Console.WriteLine(text);
18            Console.WriteLine("-------------------");
19        }
20    }
21}
22
23// MyTemplateProvider.cs
24public class MyTemplateProvider
25{
26    private readonly IHandlebars _handlebars;
27
28    public MyTemplateProvider()
29    {
30        _handlebars = Handlebars.Create();
31
32        Init(); // Add this
33    }
34
35    private void Init()
36    {
37
38        _handlebars.RegisterTemplate("MailLayout", """
39            <div>
40                <h1><strong>MyCompany - {{Title}}</strong></h1>
41                <div class="body">
42                    {{> content}}
43                </div>
44                <footer><i>MyCompany - Copyright {{On.Year}}</i></footer>
45            </div>
46            """);
47
48        // Register Welcome Mail
49        _handlebars.RegisterTemplate("WelcomeMail_Template", InternalRegisterTemplateWithLayout(
50            """
51                <h3>Welcome to our demo {{UserName}}!</h3>
52                <p>Thank you for registering. Have fun!</p>
53            """));
54    }
55
56    private string InternalRegisterTemplateWithLayout(string template)
57        => "{{#> MailLayout}}" + template + "{{/MailLayout}}";
58
59    private HandlebarsTemplate<object, object>? _welcomeTemplate = null;
60    public string RenderWelcomeMail(string userName)
61    {
62        _welcomeTemplate ??= _handlebars.Compile("{{> WelcomeMail_Template}}");
63
64        var data = new
65        {
66            Title = "Welcome!",
67            UserName = userName,
68            On = DateTimeOffset.UtcNow
69        };
70
71        var text = _welcomeTemplate(data);
72        return text;
73    }
74}