From bbefeb97a848d75b552572fb51f8c3dc06d9c7c2 Mon Sep 17 00:00:00 2001
From: Thorsten Sommer <mail@tsommer.org>
Date: Sun, 17 Jul 2022 13:26:25 +0200
Subject: [PATCH] Added some error handling to the section tree

---
 I18N Commander/Processor/SectionProcessor.cs  | 44 ++++++++++++++-----
 .../UI WinForms/Components/SectionTree.cs     | 16 +++++--
 2 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/I18N Commander/Processor/SectionProcessor.cs b/I18N Commander/Processor/SectionProcessor.cs
index 2242d94..a1a7844 100644
--- a/I18N Commander/Processor/SectionProcessor.cs	
+++ b/I18N Commander/Processor/SectionProcessor.cs	
@@ -30,7 +30,7 @@ public static class SectionProcessor
     /// <summary>
     /// Compute the new sections key and its depth, then store the section in the database.
     /// </summary>
-    public static async Task<Section> AddSection(DataContext db, string text, string? parentKey)
+    public static async Task<ProcessorResult<Section>> AddSection(DataContext db, string text, string? parentKey)
     {
         // Remove any whitespaces from the section name, regardless of how many e.g. spaces the user typed:
         var key = string.Join('_', text.Split(' ', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)).ToUpperInvariant();
@@ -58,9 +58,16 @@ public static class SectionProcessor
                 TextElements = new(),
             };
 
-            db.Sections.Add(rootSection);
-            await db.SaveChangesAsync();
-            return rootSection;
+            try
+            {
+                db.Sections.Add(rootSection);
+                await db.SaveChangesAsync();
+                return new ProcessorResult<Section>(rootSection);
+            }
+            catch (Exception e)
+            {
+                e.ToProcessorResult<Section>();
+            }
         }
 
         // Read the parent from the database:
@@ -77,10 +84,17 @@ public static class SectionProcessor
             TextElements = new(),
             Depth = parent.Depth + 1,
         };
-        
-        await db.Sections.AddAsync(section);
-        await db.SaveChangesAsync();
-        return section;
+
+        try
+        {
+            await db.Sections.AddAsync(section);
+            await db.SaveChangesAsync();
+            return new ProcessorResult<Section>(section);
+        }
+        catch (Exception e)
+        {
+            return e.ToProcessorResult<Section>();
+        }
     }
 
     public static async Task RemoveSection(DataContext db, string selectedKey)
@@ -109,7 +123,7 @@ public static class SectionProcessor
         return await db.Sections.CountAsync(n => n.Parent == section);
     }
 
-    public static async Task<Section> RenameSection(DataContext db, string selectedNodeKey, string alteredName)
+    public static async Task<ProcessorResult<Section>> RenameSection(DataContext db, string selectedNodeKey, string alteredName)
     {
         // Read the section from the database:
         var section = await db.Sections.FirstOrDefaultAsync(n => n.DataKey == selectedNodeKey);
@@ -132,8 +146,16 @@ public static class SectionProcessor
         
         section.Name = alteredName;
         section.DataKey = newKey;
-        await db.SaveChangesAsync();
-        return section;
+
+        try
+        {
+            await db.SaveChangesAsync();
+            return new ProcessorResult<Section>(section);
+        }
+        catch (Exception e)
+        {
+            return e.ToProcessorResult<Section>();
+        }
     }
 
     public static Section GetSection(DataContext db, string sectionKey) => db.Sections.First(n => n.DataKey == sectionKey);
diff --git a/I18N Commander/UI WinForms/Components/SectionTree.cs b/I18N Commander/UI WinForms/Components/SectionTree.cs
index 2ebbc55..41fc3c3 100644
--- a/I18N Commander/UI WinForms/Components/SectionTree.cs	
+++ b/I18N Commander/UI WinForms/Components/SectionTree.cs	
@@ -141,11 +141,15 @@ public partial class SectionTree : UserControl
         // Add the new section to the database:
         var addedSection = await SectionProcessor.AddSection(this.db, result.Text,  addRootNode ? null : selectedNode?.Name);
         
+        addedSection.ProcessError();
+        if(!addedSection.Successful)
+            return;
+        
         // Add the new section to the tree control:
         var node = new TreeNode
         {
-            Name = addedSection.DataKey, // [sic] name is the key
-            Text = addedSection.Name,
+            Name = addedSection.Result!.DataKey, // [sic] name is the key
+            Text = addedSection.Result.Name,
             StateImageIndex = 1,
         };
 
@@ -233,8 +237,12 @@ public partial class SectionTree : UserControl
         // Rename the section:
         var alteredSection = await SectionProcessor.RenameSection(this.db, selectedNode.Name, result.Text);
         
+        alteredSection.ProcessError();
+        if(!alteredSection.Successful)
+            return;
+        
         // Rename the selected node:
-        selectedNode.Text = alteredSection.Name;
-        selectedNode.Name = alteredSection.DataKey; // [sic] name is the key
+        selectedNode.Text = alteredSection.Result!.Name;
+        selectedNode.Name = alteredSection.Result.DataKey; // [sic] name is the key
     }
 }
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