Sitecore bucket condition for determining if a new item is made or derived from a specific template

WhenNewItemTemplateIsDerivedFrom.cs

using Sitecore.Buckets.Rules.Bucketing;
using Sitecore.Data;
using Sitecore.Data.Managers;
using Sitecore.Data.Templates;
using Sitecore.Rules.Conditions;

namespace Custom.Sitecore.Feature.Blog.BucketConditions
{
	public class WhenNewItemTemplateIsDerivedFrom<T> : WhenCondition<T> where T : BucketingRuleContext
	{
		private ID templateId;

		public WhenNewItemTemplateIsDerivedFrom()
		{
			templateId = ID.Null;
		}

		public WhenNewItemTemplateIsDerivedFrom(ID templateId)
		{
			this.templateId = templateId;
		}

		public ID TemplateId
		{
			get
			{
				return templateId;
			}
			set
			{
				templateId = value;
			}
		}

		protected override bool Execute(T ruleContext)
		{
			ID newItemTemplateId = ruleContext.NewItemTemplateId;

			if (ID.IsNullOrEmpty(newItemTemplateId)) return false;

			Template itemTemplate = TemplateManager.GetTemplate(newItemTemplateId, ruleContext.Database);
			Template baseTemplate = TemplateManager.GetTemplate(templateId, ruleContext.Database);

			return IsDerivedFrom(itemTemplate, baseTemplate);
		}

		private bool IsDerivedFrom(Template target, Template baseTemplate)
		{
			if (target.ID == baseTemplate.ID) return true;

			var baseTemplates = target.GetBaseTemplates();

			if (baseTemplates == null || baseTemplates.Count == 0) return false;

			foreach (Template bt in baseTemplates)
				if (IsDerivedFrom(bt, baseTemplate)) return true;

			return false;
		}
	}
}