Get alias of all fields that have an umbraco.tags property editor on top.

GetAliasOfAllFieldsOfDataTypeTags.gist.cs

        /// <summary>
        /// Get the alias of all document type fields 
        /// where property editor alias is Umbraco.Tags
        /// </summary>
        /// <param name="applicationContext"></param>
        /// <returns></returns>
        internal List<string> GetAliasOfAllFieldsOfDataTypeTags(ApplicationContext applicationContext)
        {
            var result = new List<string>();
            var documentTypes = applicationContext.Services.ContentTypeService.GetAllContentTypes();
            foreach (var documentType in documentTypes)
                foreach (var propertyType in documentType.PropertyTypes)
                    if (propertyType.PropertyEditorAlias.InvariantEquals("umbraco.tags"))
                        if (!result.Contains(propertyType.Alias))
                            result.Add(propertyType.Alias);
            return result;
        }