Tokenised Content in Episerver

ReplacementTokenProperty.cs

using System.ComponentModel.DataAnnotations;
using EPiServer.Core;
using EPiServer.PlugIn;

namespace TokenisedContent.Features.TokenisedContent
{
    [PropertyDefinitionTypePlugIn]
    public class ReplacementTokenProperty : PropertyList<ReplacementToken>  { }

    public class ReplacementToken
    {
        public string Token { get; set; }

        [Display(Name = "Replacement Text")]
        public string ReplacementText { get; set; }
    }

}

ReplacementTokens.cs

using System.Collections.Generic;
using EPiServer;
using EPiServer.Core;
using EPiServer.ServiceLocation;

namespace TokenisedContent.Features.TokenisedContent.Impl
{
    // Example implmentation that pulls the list of tokens from a 
    // property called ReplacementTokens on the homepage of the site
    [ServiceConfiguration(typeof(IReplacementTokens))]
    public class ReplacementTokens : IReplacementTokens
    {
        private readonly IContentRepository _contentRepository;

        public ReplacementTokens(IContentRepository contentRepository)
        {
            _contentRepository = contentRepository;
        }

        public IList<ReplacementToken> GetReplacementTokens()
        {
            var startPage = _contentRepository.Get<PageData>(ContentReference.StartPage);
            if (startPage?.Property["ReplacementTokens"] != null)
            {
                if (startPage.Property["ReplacementTokens"].Value is IList<ReplacementToken> tokens)
                {
                    return tokens;
                }
            }

            return new List<ReplacementToken>();
        }
    }

    public interface IReplacementTokens
    {
        IList<ReplacementToken> GetReplacementTokens();
    }

}

StartPage.cs

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using TokenisedContent.Features.TokenisedContent;
using EPiServer.Core;
using EPiServer.DataAbstraction;
using EPiServer.DataAnnotations;
using EPiServer.SpecializedProperties;
using TokenisedContent.Models.Blocks;
using EPiServer.Cms.Shell.UI.ObjectEditing.EditorDescriptors;
using EPiServer.Shell.ObjectEditing;

namespace TokenisedContent.Models.Pages
{
    /// <summary>
    /// Example to show how to add the property to the start page
    /// </summary>
    [ContentType(
        GUID = "19671657-B684-4D95-A61F-8DD4FE60D559",
        GroupName = Global.GroupNames.Specialized)]
    public class StartPage : SitePageData
    {
        // << Other property definitions here >>
        
        [Display(
            GroupName = "Content tokens",
            Name = "Content tokens",
            Description = "Site wide replacement tokens")]
        [EditorDescriptor(EditorDescriptorType = typeof(CollectionEditorDescriptor<ReplacementToken>))]
        public virtual IList<ReplacementToken> ReplacementTokens { get; set; }
    }
}

TokenReplacementAttribute.cs

using System.Linq;
using EPiServer.ServiceLocation;
using EPiServer.Web.Routing;
// See https://github.com/RSuter/MyToolkit and https://www.nuget.org/packages/MyToolkit.AspNet.Mvc
using MyToolkit.Filters;
using TokenisedContent.Features.TokenisedContent.Interfaces;


namespace TokenisedContent.Features.TokenisedContent.Attributes
{
    public class TokenReplacementAttribute : OutputProcessorActionFilterAttribute // See https://github.com/RSuter/MyToolkit and https://www.nuget.org/packages/MyToolkit.AspNet.Mvc
    {
#pragma warning disable 649
        private readonly Injected<IReplacementTokens> _replacementTokens;
        private readonly Injected<IPageRouteHelper> _pageRouteHelper;
#pragma warning restore 649

        protected override string Process(string data)
        {
            var currentPage = _pageRouteHelper.Service?.Page;

            if (currentPage != null)
            {
                var replacementTokens = _replacementTokens.Service?.GetReplacementTokens();
                if (replacementTokens?.Any() == true)
                {
                    // Depending on the number of replacements there may be a case for optimisation here - send me a PR ;)
                    foreach (var token in replacementTokens)
                    {
                        data = data.Replace(token.Token, token.ReplacementText);
                    }
                }
            }

            return data;
        }
    }
}

TokenReplacementInit.cs

using EPiServer.Framework;
using EPiServer.Framework.Initialization;

namespace TokenisedContent.Features.TokenisedContent
{
    [ModuleDependency(typeof(EPiServer.Web.InitializationModule))]
    public class TokenReplacementInit : IInitializableModule
    {
        public void Initialize(InitializationEngine context)
        {
            GlobalFilters.Filters.Add(ServiceLocator.Current.GetInstance<TokenReplacementAttribute>());
        }

        public void Uninitialize(InitializationEngine context) { }
    }
}