From 99b80e0f569ce24623eb331fd683b5255a64c672 Mon Sep 17 00:00:00 2001
From: Kenn Jacobsen <post@kennjacobsen.dk>
Date: Tue, 8 Jan 2019 12:19:29 +0100
Subject: [PATCH] Ensure that media in RTEs are always rendered with up-to-date
 sources

---
 .../PropertyEditors/RichTextPropertyEditor.cs |  6 ++-
 .../RteMacroRenderingValueConverter.cs        |  5 ++-
 .../Templates/TemplateUtilities.cs            | 44 +++++++++++++++++++
 3 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/src/Umbraco.Web/PropertyEditors/RichTextPropertyEditor.cs b/src/Umbraco.Web/PropertyEditors/RichTextPropertyEditor.cs
index de65a326f7..33f04d7595 100644
--- a/src/Umbraco.Web/PropertyEditors/RichTextPropertyEditor.cs
+++ b/src/Umbraco.Web/PropertyEditors/RichTextPropertyEditor.cs
@@ -4,6 +4,7 @@ using Umbraco.Core.Macros;
 using Umbraco.Core.Models;
 using Umbraco.Core.PropertyEditors;
 using Umbraco.Core.Services;
+using Umbraco.Web.Templates;
 
 namespace Umbraco.Web.PropertyEditors
 {
@@ -65,7 +66,8 @@ namespace Umbraco.Web.PropertyEditors
                 if (property.Value == null)
                     return null;
 
-                var parsed = MacroTagParser.FormatRichTextPersistedDataForEditor(property.Value.ToString(), new Dictionary<string, string>());
+                var propertyValueWithMediaResolved = TemplateUtilities.ResolveMediaFromTextString(property.Value.ToString());
+                var parsed = MacroTagParser.FormatRichTextPersistedDataForEditor(propertyValueWithMediaResolved, new Dictionary<string, string>());
                 return parsed;
             }
 
@@ -87,4 +89,4 @@ namespace Umbraco.Web.PropertyEditors
     }
 
     
-}
\ No newline at end of file
+}
diff --git a/src/Umbraco.Web/PropertyEditors/ValueConverters/RteMacroRenderingValueConverter.cs b/src/Umbraco.Web/PropertyEditors/ValueConverters/RteMacroRenderingValueConverter.cs
index a6ea79d283..c430dbc1ba 100644
--- a/src/Umbraco.Web/PropertyEditors/ValueConverters/RteMacroRenderingValueConverter.cs
+++ b/src/Umbraco.Web/PropertyEditors/ValueConverters/RteMacroRenderingValueConverter.cs
@@ -71,9 +71,10 @@ namespace Umbraco.Web.PropertyEditors.ValueConverters
 
             var sourceString = source.ToString();
 
-            // ensures string is parsed for {localLink} and urls are resolved correctly
+            // ensures string is parsed for {localLink} and urls and media are resolved correctly
             sourceString = TemplateUtilities.ParseInternalLinks(sourceString, preview);
             sourceString = TemplateUtilities.ResolveUrlsFromTextString(sourceString);
+            sourceString = TemplateUtilities.ResolveMediaFromTextString(sourceString);
 
             // ensure string is parsed for macros and macros are executed correctly
             sourceString = RenderRteMacros(sourceString, preview);
@@ -118,4 +119,4 @@ namespace Umbraco.Web.PropertyEditors.ValueConverters
             return sourceString;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Umbraco.Web/Templates/TemplateUtilities.cs b/src/Umbraco.Web/Templates/TemplateUtilities.cs
index a7e6738374..86db8092a0 100644
--- a/src/Umbraco.Web/Templates/TemplateUtilities.cs
+++ b/src/Umbraco.Web/Templates/TemplateUtilities.cs
@@ -102,6 +102,9 @@ namespace Umbraco.Web.Templates
         private static readonly Regex ResolveUrlPattern = new Regex("(=[\"\']?)(\\W?\\~(?:.(?![\"\']?\\s+(?:\\S+)=|[>\"\']))+.)[\"\']?",
             RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
 
+        private static readonly Regex ResolveImgPattern = new Regex(@"(<img[^>]*src="")([^""\?]*)([^""]*""[^>]*data-udi="")([^""]*)(""[^>]*>)",
+            RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
+
         /// <summary>
         /// The RegEx matches any HTML attribute values that start with a tilde (~), those that match are passed to ResolveUrl to replace the tilde with the application path.
         /// </summary>
@@ -145,5 +148,46 @@ namespace Umbraco.Web.Templates
         {
             return text.CleanForXss(ignoreFromClean);
         }
+
+        /// <summary>
+        /// Parses the string looking for Umbraco image tags and updates them to their up-to-date image sources.
+        /// </summary>
+        /// <param name="text"></param>
+        /// <returns></returns>
+        /// <remarks>Umbraco image tags are identified by their data-udi attributes</remarks>
+        public static string ResolveMediaFromTextString(string text)
+        {
+            // don't attempt to proceed without a context
+            if (UmbracoContext.Current == null || UmbracoContext.Current.MediaCache == null)
+            {
+                return text;
+            }
+
+            return ResolveImgPattern.Replace(text, match =>
+            {
+                // match groups:
+                // - 1 = from the beginning of the image tag until src attribute value begins
+                // - 2 = the src attribute value excluding the querystring (if present)
+                // - 3 = anything after group 2 and before the data-udi attribute value begins
+                // - 4 = the data-udi attribute value
+                // - 5 = anything after group 4 until the image tag is closed
+                var src = match.Groups[2].Value;
+                var udi = match.Groups[4].Value;
+                if(src.IsNullOrWhiteSpace() || udi.IsNullOrWhiteSpace() || GuidUdi.TryParse(udi, out var guidUdi) == false)
+                {
+                    return match.Value;
+                }
+                var media = UmbracoContext.Current.MediaCache.GetById(guidUdi.Guid);
+                if(media == null)
+                {
+                    // image does not exist - we could choose to remove the image entirely here (return empty string),
+                    // but that would leave the editors completely in the dark as to why the image doesn't show
+                    return match.Value;
+                }
+
+                var url = media.Url;
+                return $"{match.Groups[1].Value}{url}{match.Groups[3].Value}{udi}{match.Groups[5].Value}";
+            });
+        }
     }
 }