Umbraco-CMS/src/Umbraco.Web/PropertyEditors/ValueConverters/TextStringValueConverter.cs

using System;
using System.Linq;
using Umbraco.Core;
using Umbraco.Core.Models.PublishedContent;
using Umbraco.Core.PropertyEditors;
using Umbraco.Web.Composing;
using Umbraco.Web.Templates;

namespace Umbraco.Web.PropertyEditors.ValueConverters
{
    [DefaultPropertyValueConverter]
    public class TextStringValueConverter : PropertyValueConverterBase
    {
        private static readonly string[] PropertyTypeAliases =
        {
            Constants.PropertyEditors.Aliases.TextBox,
            Constants.PropertyEditors.Aliases.TextArea
        };

        public override bool IsConverter(PublishedPropertyType propertyType)
            => PropertyTypeAliases.Contains(propertyType.EditorAlias);

        public override Type GetPropertyValueType(PublishedPropertyType propertyType)
            => typeof (string);

        public override PropertyCacheLevel GetPropertyCacheLevel(PublishedPropertyType propertyType)
            => PropertyCacheLevel.Snapshot;

        public override object ConvertSourceToIntermediate(IPublishedElement owner, PublishedPropertyType propertyType, object source, bool preview)
        {
            if (source == null) return null;
            var sourceString = source.ToString();

            // ensures string is parsed for {localLink} and urls are resolved correctly
            sourceString = TemplateUtilities.ParseInternalLinks(sourceString, preview, Current.UmbracoContext);
            sourceString = TemplateUtilities.ResolveUrlsFromTextString(sourceString);

            return sourceString;
        }

        public override object ConvertIntermediateToObject(IPublishedElement owner, PublishedPropertyType propertyType, PropertyCacheLevel referenceCacheLevel, object inter, bool preview)
        {
            // source should come from ConvertSource and be a string (or null) already
            return inter ?? string.Empty;
        }

        public override object ConvertIntermediateToXPath(IPublishedElement owner, PublishedPropertyType propertyType, PropertyCacheLevel referenceCacheLevel, object inter, bool preview)
        {
            // source should come from ConvertSource and be a string (or null) already
            return inter;
        }
    }
}