Merge branch 'main' of http://git.dd:3000/AppStd/DbFirst

Refactored CatalogApiClient methods to return ApiResult<T> for create, update, and delete operations, enabling more detailed error reporting. Introduced ApiResult<T> and ProblemDetailsDto types, and added logic to parse and display informative error messages. Updated Catalogs.razor to use the new pattern and show user-friendly error feedback. Added necessary using directives.

DbFirst.API/Controllers/CatalogsController.cs

@@ -36,12 +36,26 @@ public class CatalogsController : ControllerBase
     public async Task<ActionResult<CatalogReadDto>> Create(CatalogWriteDto dto, CancellationToken cancellationToken)
     {
         var created = await _service.CreateAsync(dto, cancellationToken);
+        if (created == null)
+        {
+            return Conflict();
+        }
         return CreatedAtAction(nameof(GetById), new { id = created.Guid }, created);
     }
 
     [HttpPut("{id:int}")]
     public async Task<ActionResult<CatalogReadDto>> Update(int id, CatalogWriteDto dto, CancellationToken cancellationToken)
     {
+        var current = await _service.GetByIdAsync(id, cancellationToken);
+        if (current == null)
+        {
+            return NotFound();
+        }
+        if (!string.Equals(current.CatTitle, dto.CatTitle, StringComparison.Ordinal))
+        {
+            return BadRequest("CatTitle cannot be changed.");
+        }
+
         var updated = await _service.UpdateAsync(id, dto, cancellationToken);
         if (updated == null)
         {

DbFirst.Application/Catalogs/CatalogService.cs

@@ -29,8 +29,14 @@ public class CatalogService : ICatalogService
         return item == null ? null : _mapper.Map<CatalogReadDto>(item);
     }
 
-    public async Task<CatalogReadDto> CreateAsync(CatalogWriteDto dto, CancellationToken cancellationToken = default)
+    public async Task<CatalogReadDto?> CreateAsync(CatalogWriteDto dto, CancellationToken cancellationToken = default)
     {
+        var existing = await _repository.GetByTitleAsync(dto.CatTitle, cancellationToken);
+        if (existing != null)
+        {
+            return null;
+        }
+
         var entity = _mapper.Map<VwmyCatalog>(dto);
         entity.AddedWho = "system";
         entity.AddedWhen = DateTime.UtcNow;
@@ -51,6 +57,7 @@ public class CatalogService : ICatalogService
 
         var entity = _mapper.Map<VwmyCatalog>(dto);
         entity.Guid = id;
+        entity.CatTitle = existing.CatTitle;
         entity.AddedWho = existing.AddedWho;
         entity.AddedWhen = existing.AddedWhen;
         entity.ChangedWho = "system";

DbFirst.Application/Catalogs/ICatalogService.cs

@@ -5,7 +5,7 @@ public interface ICatalogService
 {
     Task<List<CatalogReadDto>> GetAllAsync(CancellationToken cancellationToken = default);
     Task<CatalogReadDto?> GetByIdAsync(int id, CancellationToken cancellationToken = default);
-    Task<CatalogReadDto> CreateAsync(CatalogWriteDto dto, CancellationToken cancellationToken = default);
+    Task<CatalogReadDto?> CreateAsync(CatalogWriteDto dto, CancellationToken cancellationToken = default);
     Task<CatalogReadDto?> UpdateAsync(int id, CatalogWriteDto dto, CancellationToken cancellationToken = default);
     Task<bool> DeleteAsync(int id, CancellationToken cancellationToken = default);
 }

DbFirst.BlazorWasm/Pages/Catalogs.razor

@@ -151,9 +151,9 @@ else
             if (isEditing)
             {
                 var updated = await Api.UpdateAsync(editingId, formModel);
-                if (!updated)
+                if (!updated.Success)
                 {
-                    errorMessage = "Aktualisierung fehlgeschlagen.";
+                    errorMessage = updated.Error ?? "Aktualisierung fehlgeschlagen.";
                     return;
                 }
 
@@ -162,9 +162,9 @@ else
             else
             {
                 var created = await Api.CreateAsync(formModel);
-                if (created == null)
+                if (!created.Success || created.Value == null)
                 {
-                    errorMessage = "Anlegen fehlgeschlagen.";
+                    errorMessage = created.Error ?? "Anlegen fehlgeschlagen.";
                     return;
                 }
 
@@ -195,9 +195,9 @@ else
         try
         {
             var deleted = await Api.DeleteAsync(id);
-            if (!deleted)
+            if (!deleted.Success)
             {
-                errorMessage = "Löschen fehlgeschlagen.";
+                errorMessage = deleted.Error ?? "Löschen fehlgeschlagen.";
                 return;
             }
 

DbFirst.BlazorWasm/Services/CatalogApiClient.cs

@@ -1,4 +1,6 @@
+using System.Net;
 using System.Net.Http.Json;
+using System.Text.Json;
 using DbFirst.BlazorWasm.Models;
 
 namespace DbFirst.BlazorWasm.Services;
@@ -24,26 +26,114 @@ public class CatalogApiClient
         return await _httpClient.GetFromJsonAsync<CatalogReadDto>($"{Endpoint}/{id}");
     }
 
-    public async Task<CatalogReadDto?> CreateAsync(CatalogWriteDto dto)
+    public async Task<ApiResult<CatalogReadDto?>> CreateAsync(CatalogWriteDto dto)
     {
         var response = await _httpClient.PostAsJsonAsync(Endpoint, dto);
-        if (!response.IsSuccessStatusCode)
+        if (response.IsSuccessStatusCode)
         {
-            return null;
+            var payload = await response.Content.ReadFromJsonAsync<CatalogReadDto>();
+            return ApiResult<CatalogReadDto?>.Ok(payload);
         }
 
-        return await response.Content.ReadFromJsonAsync<CatalogReadDto>();
+        var error = await ReadErrorAsync(response);
+        return ApiResult<CatalogReadDto?>.Fail(error);
     }
 
-    public async Task<bool> UpdateAsync(int id, CatalogWriteDto dto)
+    public async Task<ApiResult<bool>> UpdateAsync(int id, CatalogWriteDto dto)
     {
         var response = await _httpClient.PutAsJsonAsync($"{Endpoint}/{id}", dto);
-        return response.IsSuccessStatusCode;
+        if (response.IsSuccessStatusCode)
+        {
+            return ApiResult<bool>.Ok(true);
+        }
+
+        var error = await ReadErrorAsync(response);
+        return ApiResult<bool>.Fail(error);
     }
 
-    public async Task<bool> DeleteAsync(int id)
+    public async Task<ApiResult<bool>> DeleteAsync(int id)
     {
         var response = await _httpClient.DeleteAsync($"{Endpoint}/{id}");
-        return response.IsSuccessStatusCode;
+        if (response.IsSuccessStatusCode)
+        {
+            return ApiResult<bool>.Ok(true);
+        }
+
+        var error = await ReadErrorAsync(response);
+        return ApiResult<bool>.Fail(error);
+    }
+
+    private static async Task<string> ReadErrorAsync(HttpResponseMessage response)
+    {
+        string? problemTitle = null;
+        string? problemDetail = null;
+
+        try
+        {
+            var problem = await response.Content.ReadFromJsonAsync<ProblemDetailsDto>();
+            if (problem != null)
+            {
+                problemTitle = problem.Title;
+                problemDetail = problem.Detail ?? problem.Type;
+            }
+        }
+        catch
+        {
+            // ignore parse errors
+        }
+
+        var status = response.StatusCode;
+        var reason = response.ReasonPhrase;
+        var body = await response.Content.ReadAsStringAsync();
+
+        string detail = problemDetail;
+        if (string.IsNullOrWhiteSpace(detail) && !string.IsNullOrWhiteSpace(body))
+        {
+            detail = body;
+        }
+
+        // Friendly overrides
+        if (status == HttpStatusCode.Conflict)
+        {
+            return "Datensatz existiert bereits. Bitte wählen Sie einen anderen Titel.";
+        }
+        if (status == HttpStatusCode.BadRequest && (detail?.Contains("CatTitle cannot be changed", StringComparison.OrdinalIgnoreCase) ?? false))
+        {
+            return "Titel kann nicht geändert werden.";
+        }
+
+        return status switch
+        {
+            HttpStatusCode.BadRequest => $"Eingabe ungültig{FormatSuffix(problemTitle, detail, reason)}",
+            HttpStatusCode.NotFound => $"Nicht gefunden{FormatSuffix(problemTitle, detail, reason)}",
+            HttpStatusCode.Conflict => $"Konflikt{FormatSuffix(problemTitle, detail, reason)}",
+            HttpStatusCode.Unauthorized => $"Nicht autorisiert{FormatSuffix(problemTitle, detail, reason)}",
+            HttpStatusCode.Forbidden => $"Nicht erlaubt{FormatSuffix(problemTitle, detail, reason)}",
+            HttpStatusCode.InternalServerError => $"Serverfehler{FormatSuffix(problemTitle, detail, reason)}",
+            _ => $"Fehler {(int)status} {reason ?? string.Empty}{FormatSuffix(problemTitle, detail, reason)}"
+        };
+    }
+
+    private static string FormatSuffix(string? title, string? detail, string? reason)
+    {
+        var parts = new List<string>();
+        if (!string.IsNullOrWhiteSpace(title)) parts.Add(title);
+        if (!string.IsNullOrWhiteSpace(detail)) parts.Add(detail);
+        if (parts.Count == 0 && !string.IsNullOrWhiteSpace(reason)) parts.Add(reason);
+        if (parts.Count == 0) return string.Empty;
+        return ": " + string.Join(" | ", parts);
     }
 }
+
+public record ApiResult<T>(bool Success, T? Value, string? Error)
+{
+    public static ApiResult<T> Ok(T? value) => new(true, value, null);
+    public static ApiResult<T> Fail(string? error) => new(false, default, error);
+}
+
+internal sealed class ProblemDetailsDto
+{
+    public string? Type { get; set; }
+    public string? Title { get; set; }
+    public string? Detail { get; set; }
+}

DbFirst.Domain/Repositories/ICatalogRepository.cs

@@ -8,6 +8,7 @@ public interface ICatalogRepository
 {
     Task<List<VwmyCatalog>> GetAllAsync(CancellationToken cancellationToken = default);
     Task<VwmyCatalog?> GetByIdAsync(int id, CancellationToken cancellationToken = default);
+    Task<VwmyCatalog?> GetByTitleAsync(string title, CancellationToken cancellationToken = default);
     Task<VwmyCatalog> InsertAsync(VwmyCatalog catalog, CancellationToken cancellationToken = default);
     Task<VwmyCatalog?> UpdateAsync(int id, VwmyCatalog catalog, CancellationToken cancellationToken = default);
     Task<bool> DeleteAsync(int id, CancellationToken cancellationToken = default);

DbFirst.Infrastructure/Repositories/CatalogRepository.cs

@@ -26,6 +26,11 @@ public class CatalogRepository : ICatalogRepository
         return await _db.VwmyCatalogs.AsNoTracking().FirstOrDefaultAsync(x => x.Guid == id, cancellationToken);
     }
 
+    public async Task<VwmyCatalog?> GetByTitleAsync(string title, CancellationToken cancellationToken = default)
+    {
+        return await _db.VwmyCatalogs.AsNoTracking().FirstOrDefaultAsync(x => x.CatTitle == title, cancellationToken);
+    }
+
     public async Task<VwmyCatalog> InsertAsync(VwmyCatalog catalog, CancellationToken cancellationToken = default)
     {
         var guidParam = new SqlParameter("@GUID", SqlDbType.Int)
@@ -63,8 +68,7 @@ public class CatalogRepository : ICatalogRepository
 
         var guidParam = new SqlParameter("@GUID", SqlDbType.Int)
         {
-            Direction = ParameterDirection.Input,
-            Value = id
+            Direction = ParameterDirection.Output
         };
 
         var catTitleParam = new SqlParameter("@CAT_TITLE", catalog.CatTitle);
@@ -72,11 +76,22 @@ public class CatalogRepository : ICatalogRepository
         var changedWhoParam = new SqlParameter("@CHANGED_WHO", (object?)catalog.ChangedWho ?? DBNull.Value);
 
         await _db.Database.ExecuteSqlRawAsync(
-            "EXEC dbo.PRTBMY_CATALOG_UPDATE @CAT_TITLE, @CAT_STRING, @CHANGED_WHO, @GUID",
+            "EXEC dbo.PRTBMY_CATALOG_UPDATE @CAT_TITLE, @CAT_STRING, @CHANGED_WHO, @GUID OUTPUT",
             parameters: new[] { catTitleParam, catStringParam, changedWhoParam, guidParam },
             cancellationToken: cancellationToken);
 
-        return await _db.VwmyCatalogs.AsNoTracking().FirstOrDefaultAsync(x => x.Guid == id, cancellationToken);
+        if (guidParam.Value == DBNull.Value)
+        {
+            return null;
+        }
+
+        var guid = (int)guidParam.Value;
+        if (guid == 0)
+        {
+            return null;
+        }
+
+        return await _db.VwmyCatalogs.AsNoTracking().FirstOrDefaultAsync(x => x.Guid == guid, cancellationToken);
     }
 
     public async Task<bool> DeleteAsync(int id, CancellationToken cancellationToken = default)