Revize c9121169

Added rollback of tag addition/removal

Backend/Core/Services/AnnotationService/AnnotationServiceEF.cs

@@ -239 +239 @@
                 // The annotation has been modified and we need to either add the new tag or remove the tag
                 if (annotation.ModifiedType != EModified.NONE)
                 {
-                    if (annotation.ModifiedType == EModified.ADDED)
+                    // Try to add or remove the tag
+                    try
                     {
-
-                        AnnotationTagGeneric lastModifiedTag = isFinal ? context.FinalAnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First() :
-                            context.AnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First();
-
-                        var result = htmlService.PartialPreprocessHTMLAddTag(docToRender, documentContent.Content, lastModifiedTag, tags, cachedInfoToReturn);
-                        docToRender = result.Item1;
-                        cachedInfoToReturn = result.Item2;
+                        if (annotation.ModifiedType == EModified.ADDED)
+                        {
+
+                            AnnotationTagGeneric lastModifiedTag = isFinal ? context.FinalAnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First() :
+                                context.AnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First();
+
+                            var result = htmlService.PartialPreprocessHTMLAddTag(docToRender, documentContent.Content, lastModifiedTag, tags, cachedInfoToReturn);
+                            docToRender = result.Item1;
+                            cachedInfoToReturn = result.Item2;
+                        }
+                        else if (annotation.ModifiedType == EModified.REMOVED)
+                        {
+                            var result = htmlService.PartialPreprocessHTMLRemoveTag(docToRender, documentContent.Content, new AnnotationTag() { Id = annotation.LastModifiedTagId.Value }, tags, cachedInfoToReturn);
+                            docToRender = result.Item1;
+                            cachedInfoToReturn = result.Item2;
+                        }
+
+                        annotation.ModifiedType = EModified.NONE;
+                        annotation.CachedStartPositions = JsonConvert.SerializeObject(cachedInfoToReturn.TagStartPositions);
+                        annotation.CachedLengths = JsonConvert.SerializeObject(cachedInfoToReturn.TagStartLengths);
+                        annotation.CachedClosingPositions = JsonConvert.SerializeObject(cachedInfoToReturn.TagClosingPositions);
+                        annotation.CachedClosingLengths = JsonConvert.SerializeObject(cachedInfoToReturn.TagClosingLengths);
+                        annotation.CachedDocumentHTML = docToRender;
+                        annotation.CachedCSS = JsonConvert.SerializeObject(cachedInfoToReturn.TagInstanceCSS);
+                        context.SaveChanges();
                     }
-                    else if (annotation.ModifiedType == EModified.REMOVED)
+                    catch (Exception ex)
                     {
-                        var result = htmlService.PartialPreprocessHTMLRemoveTag(docToRender, documentContent.Content, new AnnotationTag() { Id = annotation.LastModifiedTagId.Value }, tags, cachedInfoToReturn);
-                        docToRender = result.Item1;
-                        cachedInfoToReturn = result.Item2;
+                        // If the adding or removing fails, then undo the changes, make the selection invalid and revert to previous state
+                        if (isFinal)
+                        {
+                            FinalAnnotationTag fat = context.FinalAnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First();
+                            context.FinalAnnotationTags.Remove(fat);
+                        }
+                        else 
+                        {
+                            AnnotationTag at = context.AnnotationTags.Where(at => at.Id == annotation.LastModifiedTagId).First();
+                            context.AnnotationTags.Remove(at);
+                        }
+
+                        annotation.ModifiedType = EModified.NONE;
+                        context.SaveChanges();
+
+                        throw new InvalidOperationException("The selection is invalid.");
                     }
-
-                    annotation.ModifiedType = EModified.NONE;
-                    annotation.CachedStartPositions = JsonConvert.SerializeObject(cachedInfoToReturn.TagStartPositions);
-                    annotation.CachedLengths = JsonConvert.SerializeObject(cachedInfoToReturn.TagStartLengths);
-                    annotation.CachedClosingPositions = JsonConvert.SerializeObject(cachedInfoToReturn.TagClosingPositions);
-                    annotation.CachedClosingLengths = JsonConvert.SerializeObject(cachedInfoToReturn.TagClosingLengths);
-                    annotation.CachedDocumentHTML = docToRender;
-                    annotation.CachedCSS = JsonConvert.SerializeObject(cachedInfoToReturn.TagInstanceCSS);
-                    context.SaveChanges();
                 }
             }