Refactored service provider usage

- Remove service provider from WinForms altogether
- Moved service provider handling to processors

I18N Commander/Processor/SectionProcessor.cs

@@ -1,6 +1,7 @@
 using DataModel.Database;
 using DataModel.Database.Common;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Processor;
 
@@ -9,16 +10,24 @@ public static class SectionProcessor
     /// <summary>
     /// Load one layer of the tree by using the specified depth:
     /// </summary>
-    public static IAsyncEnumerable<Section> LoadLayer(DataContext db, int depth)
+    public static async Task<List<Section>> LoadLayer(int depth)
     {
-        return db.Sections.Where(n => n.Depth == depth).OrderBy(n => n.Id).AsAsyncEnumerable();
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        var sections = await db.Sections.Where(n => n.Depth == depth).OrderBy(n => n.Id).ToListAsync();
+        
+        // Ensure, that the database loaded the section's parent:
+        foreach (var section in sections)
+            await db.Entry(section).Reference(n => n.Parent).LoadAsync();
+
+        return sections;
     }
 
     /// <summary>
     /// Determine how deep the tree is.
     /// </summary>
-    public static async ValueTask<int> GetDepth(DataContext db)
+    public static async ValueTask<int> GetDepth()
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
         if(!await db.Sections.AnyAsync())
         {
             return 0;
@@ -30,8 +39,10 @@ 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<ProcessorResult<Section>> AddSection(DataContext db, string text, string? parentKey)
+    public static async Task<ProcessorResult<Section>> AddSection(string text, string? parentKey)
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        
         // 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();
         
@@ -97,24 +108,32 @@ public static class SectionProcessor
         }
     }
 
-    public static async Task RemoveSection(DataContext db, string selectedKey)
+    public static async Task RemoveSection(string selectedKey)
+    {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        await SectionProcessor.RemoveOneSectionAndItsChildren(db, selectedKey);
+        await db.SaveChangesAsync();
+    }
+
+    private static async Task RemoveOneSectionAndItsChildren(DataContext db, string selectedKey)
     {
         // Remove the section from the database:
         var section2Delete = await db.Sections.FirstOrDefaultAsync(n => n.DataKey == selectedKey);
         if (section2Delete is null)
             throw new ArgumentException($"The section with key {selectedKey} does not exist in the database.");
-        
+
         // Next, remove all children of the section, and the children's children, etc.:
         var children = await db.Sections.Where(n => n.Parent == section2Delete).ToListAsync();
         foreach (var child in children)
-            await RemoveSection(db, child.DataKey);
+            await SectionProcessor.RemoveOneSectionAndItsChildren(db, child.DataKey);
 
         db.Sections.Remove(section2Delete);
-        await db.SaveChangesAsync();
     }
-    
+
-    public static async Task<int> NumberChildren(DataContext db, string selectedKey)
+    public static async Task<int> NumberChildren(string selectedKey)
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        
         // Read the section from the database:
         var section = await db.Sections.FirstOrDefaultAsync(n => n.DataKey == selectedKey);
         if (section is null)
@@ -123,8 +142,10 @@ public static class SectionProcessor
         return await db.Sections.CountAsync(n => n.Parent == section);
     }
 
-    public static async Task<ProcessorResult<Section>> RenameSection(DataContext db, string selectedNodeKey, string alteredName)
+    public static async Task<ProcessorResult<Section>> RenameSection(string selectedNodeKey, string alteredName)
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        
         // Read the section from the database:
         var section = await db.Sections.FirstOrDefaultAsync(n => n.DataKey == selectedNodeKey);
         if (section is null)
@@ -158,10 +179,18 @@ public static class SectionProcessor
         }
     }
 
-    public static Section GetSection(DataContext db, string sectionKey) => db.Sections.First(n => n.DataKey == sectionKey);
+    public static async Task<Section> GetSection(string sectionKey)
-
-    public static async Task<string> GetSectionPath(DataContext db, string sectionKey)
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        var section = await db.Sections.FirstAsync(n => n.DataKey == sectionKey);
+        await db.Entry(section).Reference(n => n.Parent).LoadAsync();
+
+        return section;
+    }
+
+    public static async Task<string> GetSectionPath(string sectionKey)
+    {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
         var section = await db.Sections.FirstAsync(n => n.DataKey == sectionKey);
         
         // Ensure, that the database loaded the section's parent:

I18N Commander/Processor/TextElementProcessor.cs

@@ -1,18 +1,22 @@
 using DataModel.Database;
 using DataModel.Database.Common;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Processor;
 
 public static class TextElementProcessor
 {
-    public static Task<IAsyncEnumerable<TextElement>> GetTextElements(DataContext db, Section section)
+    public static async Task<List<TextElement>> GetTextElements(Section section)
     {
-        return Task.FromResult(db.TextElements.Where(n => n.Section == section).AsAsyncEnumerable());
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        return await db.TextElements.Where(n => n.Section == section).ToListAsync();
     }
 
-    public static async Task<ProcessorResult<TextElement>> AddTextElement(DataContext db, string? currentSectionKey, string elementName)
+    public static async Task<ProcessorResult<TextElement>> AddTextElement(string? currentSectionKey, string elementName)
     {
+        await using var db = ProcessorMeta.ServiceProvider.GetRequiredService<DataContext>();
+        
         if(string.IsNullOrWhiteSpace(currentSectionKey))
             throw new ArgumentOutOfRangeException(nameof(currentSectionKey));
         

I18N Commander/UI WinForms/Components/SectionTree.cs

@@ -1,6 +1,4 @@
-using DataModel.Database.Common;
+using Processor;
-using Microsoft.Extensions.DependencyInjection;
-using Processor;
 using UI_WinForms.Dialogs;
 using UI_WinForms.Resources;
 
@@ -8,8 +6,6 @@ namespace UI_WinForms.Components;
 
 public partial class SectionTree : UserControl
 {
-    private readonly DataContext db;
-    
     public SectionTree()
     {
         this.InitializeComponent();
@@ -18,12 +14,6 @@ public partial class SectionTree : UserControl
         if(Program.SERVICE_PROVIDER is null)
             return;
         
-        // Get the DI context from the main form:
-        this.db = Program.SERVICE_PROVIDER.GetService<DataContext>()!;
-        
-        // Dispose of the context when the control is disposed:
-        this.Disposed += (_, _) => this.db.Dispose();
-
         // Create an image list from a resource:
         var imgList = new ImageList();
         imgList.ImageSize = new Size(45, 45);
@@ -46,7 +36,7 @@ public partial class SectionTree : UserControl
         var treeNodes = new Dictionary<string, TreeNode>();
 
         // Get the max. depth of the tree:
-        var maxDepth = await SectionProcessor.GetDepth(this.db);
+        var maxDepth = await SectionProcessor.GetDepth();
         
         // Store nodes, where we cannot find the parents:
         var missingParents = new List<TreeNode>();
@@ -54,7 +44,7 @@ public partial class SectionTree : UserControl
         // Populate the tree view out of the database, layer by layer:
         for (var i = 0; i <= maxDepth; i++)
         {
-            await foreach (var section in SectionProcessor.LoadLayer(this.db, i))
+            foreach (var section in await SectionProcessor.LoadLayer(i))
             {
                 // Create the tree node:
                 var node = new TreeNode
@@ -139,7 +129,7 @@ public partial class SectionTree : UserControl
         var selectedNode = this.treeView.SelectedNode;
 
         // Add the new section to the database:
-        var addedSection = await SectionProcessor.AddSection(this.db, result.Text,  addRootNode ? null : selectedNode?.Name);
+        var addedSection = await SectionProcessor.AddSection(result.Text,  addRootNode ? null : selectedNode?.Name);
         
         addedSection.ProcessError();
         if(!addedSection.Successful)
@@ -173,7 +163,7 @@ public partial class SectionTree : UserControl
         
         // Get the number of children:
         // (notice, that the node's name is its key)
-        var numberChildren = await SectionProcessor.NumberChildren(this.db, selectedNode.Name);
+        var numberChildren = await SectionProcessor.NumberChildren(selectedNode.Name);
         
         // Ask the user, if he really wants to remove the section:
         if(MessageBox.Show(numberChildren > 0 ? $"Are you sure, you want to remove the section '{selectedNode.Text}', its {numberChildren} children and so on?" : $"Are you sure, you want to remove the section '{selectedNode.Text}'?", "Remove section", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.No)
@@ -181,7 +171,7 @@ public partial class SectionTree : UserControl
         
         // Remove the section from the database:
         // (notice, that the node's name is its key)
-        await SectionProcessor.RemoveSection(this.db, selectedNode.Name);
+        await SectionProcessor.RemoveSection(selectedNode.Name);
         
         // Remove all nodes from the tree control:
         this.treeView.Nodes.Clear();
@@ -190,7 +180,7 @@ public partial class SectionTree : UserControl
         this.LoadNodes(this, EventArgs.Empty);
     }
 
-    private void treeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
+    private async void treeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
     {
         if(this.DesignMode)
             return;
@@ -205,7 +195,7 @@ public partial class SectionTree : UserControl
         if (selectedNode is not null)
         {
             // Get the section from the database:
-            var section = SectionProcessor.GetSection(this.db, selectedNode.Name);
+            var section = await SectionProcessor.GetSection(selectedNode.Name);
             AppEvents.SectionChanged(section);
         }
     }
@@ -235,7 +225,7 @@ public partial class SectionTree : UserControl
             return;
         
         // Rename the section:
-        var alteredSection = await SectionProcessor.RenameSection(this.db, selectedNode.Name, result.Text);
+        var alteredSection = await SectionProcessor.RenameSection(selectedNode.Name, result.Text);
         
         alteredSection.ProcessError();
         if(!alteredSection.Successful)

I18N Commander/UI WinForms/Components/TextElements.cs

@@ -1,6 +1,4 @@
 using DataModel.Database;
-using DataModel.Database.Common;
-using Microsoft.Extensions.DependencyInjection;
 using Processor;
 using UI_WinForms.Dialogs;
 
@@ -8,8 +6,6 @@ namespace UI_WinForms.Components;
 
 public partial class TextElements : UserControl
 {
-    private readonly DataContext db;
-    
     private Section? currentSection;
     
     public TextElements()
@@ -20,12 +16,6 @@ public partial class TextElements : UserControl
         if(Program.SERVICE_PROVIDER is null)
             return;
         
-        // Get the DI context from the main form:
-        this.db = Program.SERVICE_PROVIDER.GetService<DataContext>()!;
-        
-        // Dispose of the context when the control is disposed:
-        this.Disposed += (_, _) => this.db.Dispose();
-        
         // When the section is changed, update this component:
         AppEvents.WhenSectionChanged += async (sender, section) =>
         {
@@ -36,7 +26,7 @@ public partial class TextElements : UserControl
             if (this.currentSection is null)
                 return;
             
-            this.labelSectionPath.Text = await SectionProcessor.GetSectionPath(this.db, this.currentSection.DataKey);
+            this.labelSectionPath.Text = await SectionProcessor.GetSectionPath(this.currentSection.DataKey);
             this.LoadTextElements();
         };
     }
@@ -48,11 +38,11 @@ public partial class TextElements : UserControl
             return;
         
         // Load the text elements:
-        var textElements = await TextElementProcessor.GetTextElements(this.db, this.currentSection);
+        var textElements = await TextElementProcessor.GetTextElements(this.currentSection);
         
         // Update the list:
         this.listTextElements.Items.Clear();
-        await foreach (var textElement in textElements)
+        foreach (var textElement in textElements)
         {
             var item = new ListViewItem(textElement.Name)
             {
@@ -79,7 +69,7 @@ public partial class TextElements : UserControl
             return;
         
         // Add the text element to the database into the current section:
-        var newTextElement = await TextElementProcessor.AddTextElement(this.db, this.currentSection?.DataKey, result.Text);
+        var newTextElement = await TextElementProcessor.AddTextElement(this.currentSection?.DataKey, result.Text);
         newTextElement.ProcessError();
         
         if(!newTextElement.Successful)

I18N Commander/UI WinForms/Program.cs

@@ -2,6 +2,7 @@ using DataModel;
 using DataModel.Database.Common;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Processor;
 
 namespace UI_WinForms;
 
@@ -34,9 +35,6 @@ internal static class Program
         //
         builder.ConfigureServices((hostContext, serviceCollection) =>
         {
-            // The main form:
-            serviceCollection.AddSingleton<Main>();
-
             // The database:
             serviceCollection.AddDatabase(loader.DataFile, true);
         });
@@ -50,15 +48,15 @@ internal static class Program
             // Get a service provider:
             SERVICE_PROVIDER = scope.ServiceProvider;
 
+            // Set the service provider to the processor:
+            ProcessorMeta.ServiceProvider = SERVICE_PROVIDER;
+            
             // Apply database migrations:
             using (var database = SERVICE_PROVIDER.GetRequiredService<DataContext>())
                 Setup.PerformDataMigration(database).Wait();
 
-            // Create the main window:
-            var mainWindow = SERVICE_PROVIDER.GetService<Main>();
-            
             // Start the app:
-            Application.Run(mainWindow);
+            Application.Run(new Main());
         }
     }
 }