gfoidl/HtmlTemplate.tt

## HtmlTemplate.tt
<#@ template debug="true" hostspecific="false" language="C#" #>
<html>
<head>
    <style>
        .myclass-1 {
            margin-bottom: 1em;
            background-color: lime;
        }
    </style>
</head>
<body>
<div class="myclass-1">
    Table generated by template.
</div>
<div>
    <table>
        <thead>
            <tr>
                <th>Id</th>
                <th>Name</th>
            </tr>
        </thead>
        <tbody>
        <# foreach (Person person in this.Model.Persons)
           { #>
            <tr>
                <td><#= person.Id #></td>
                <td><#= person.Name #></td>
            </tr>
        <# } #>
        </tbody>
    </table>
</div>
</body>
</html>

## HtmlTemplateRenderer.csproj
<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net5.0</TargetFramework>
    </PropertyGroup>

    <ItemGroup>
        <None Update="HtmlTemplate.tt" Generator="TextTemplatingFilePreprocessor" LastGenOutput="HtmlTemplate.cs" />
    </ItemGroup>

    <ItemGroup>
        <PackageReference Include="System.CodeDom" Version="4.7.0" />
    </ItemGroup>

    <ItemGroup>
        <Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
    </ItemGroup>

    <ItemGroup>
        <Compile Update="HtmlTemplate.cs">
            <DesignTime>True</DesignTime>
            <AutoGen>True</AutoGen>
            <DependentUpon>HtmlTemplate.tt</DependentUpon>
        </Compile>
    </ItemGroup>

</Project>

## Program.cs
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace HtmlTemplateRenderer
{
    class Program
    {
        static void Main(string[] args)
        {
            var model = new Model { Persons = GetPersons().ToList() };
            var template = new HtmlTemplate(model);

            string rendered = template.TransformText();
            File.WriteAllText("index.html", rendered);
        }

        private static IEnumerable<Person> GetPersons()
        {
            yield return new Person { Id = 1, Name = "Anton" };
            yield return new Person { Id = 2, Name = "Berta" };
        }
    }

    partial class HtmlTemplate
    {
        public Model Model { get; }

        public HtmlTemplate(Model model) => this.Model = model;
    }

    public class Model
    {
        public List<Person> Persons { get; set; }
    }

    public class Person
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}
	<#@ template debug="true" hostspecific="false" language="C#" #>
	<html>
	<head>
	<style>
	.myclass-1 {
	margin-bottom: 1em;
	background-color: lime;
	}
	</style>
	</head>
	<body>
	<div class="myclass-1">
	Table generated by template.
	</div>
	<div>
	<table>
	<thead>
	<tr>
	<th>Id</th>
	<th>Name</th>
	</tr>
	</thead>
	<tbody>
	<# foreach (Person person in this.Model.Persons)
	{ #>
	<tr>
	<td><#= person.Id #></td>
	<td><#= person.Name #></td>
	</tr>
	<# } #>
	</tbody>
	</table>
	</div>
	</body>
	</html>
	<Project Sdk="Microsoft.NET.Sdk">

	<PropertyGroup>
	<OutputType>Exe</OutputType>
	<TargetFramework>net5.0</TargetFramework>
	</PropertyGroup>

	<ItemGroup>
	<None Update="HtmlTemplate.tt" Generator="TextTemplatingFilePreprocessor" LastGenOutput="HtmlTemplate.cs" />
	</ItemGroup>

	<ItemGroup>
	<PackageReference Include="System.CodeDom" Version="4.7.0" />
	</ItemGroup>

	<ItemGroup>
	<Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
	</ItemGroup>

	<ItemGroup>
	<Compile Update="HtmlTemplate.cs">
	<DesignTime>True</DesignTime>
	<AutoGen>True</AutoGen>
	<DependentUpon>HtmlTemplate.tt</DependentUpon>
	</Compile>
	</ItemGroup>

	</Project>
	using System.Collections.Generic;
	using System.IO;
	using System.Linq;

	namespace HtmlTemplateRenderer
	{
	class Program
	{
	static void Main(string[] args)
	{
	var model = new Model { Persons = GetPersons().ToList() };
	var template = new HtmlTemplate(model);

	string rendered = template.TransformText();
	File.WriteAllText("index.html", rendered);
	}

	private static IEnumerable<Person> GetPersons()
	{
	yield return new Person { Id = 1, Name = "Anton" };
	yield return new Person { Id = 2, Name = "Berta" };
	}
	}

	partial class HtmlTemplate
	{
	public Model Model { get; }

	public HtmlTemplate(Model model) => this.Model = model;
	}

	public class Model
	{
	public List<Person> Persons { get; set; }
	}

	public class Person
	{
	public int Id { get; set; }
	public string Name { get; set; }
	}
	}