feat: add sorting to countries controller

Server/Helpers/ISortHelper.cs

@@ -0,0 +1,6 @@
+namespace Server.Helpers;
+
+public interface ISortHelper<T>
+{
+    IQueryable<T> ApplySort(IQueryable<T> entities, string? orderByQueryString);
+}

Server/Helpers/SortHelper.cs

@@ -0,0 +1,46 @@
+using System.Linq.Dynamic.Core;
+using System.Reflection;
+using System.Text;
+
+namespace Server.Helpers;
+
+public class SortHelper<T> : ISortHelper<T>
+{
+    public IQueryable<T> ApplySort(IQueryable<T> entities, string? orderByQueryString)
+    {
+        if (!entities.Any() || String.IsNullOrWhiteSpace(orderByQueryString))
+        {
+            return entities;
+        }
+
+        var orderParams = orderByQueryString.Trim().Split(",");
+        var propertyInfos =
+            typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
+        var orderQueryBuilder = new StringBuilder();
+        
+        foreach (var param in orderParams)
+        {
+            if (string.IsNullOrWhiteSpace(param))
+            {
+                continue;
+            }
+            
+            var propertyFromQueryName = param[0] == '-' || param[0] == '+' ? param.Substring(1) : param;
+            var objectProperty = propertyInfos.FirstOrDefault(pi =>
+                pi.Name.Equals(propertyFromQueryName, StringComparison.InvariantCultureIgnoreCase));
+
+            if (objectProperty == null)
+            {
+                continue;
+            }
+            
+            var sortingOrder = param[0] == '-' ? "descending" : "ascending";
+            
+            orderQueryBuilder.Append($"{objectProperty.Name} {sortingOrder}, ");
+        }
+
+        var orderQuery = orderQueryBuilder.ToString().TrimEnd(',', ' ');
+
+        return entities.OrderBy(orderQuery);
+    }
+}

Server/Program.cs

@@ -7,6 +7,7 @@ using Microsoft.OpenApi.Models;
 using Newtonsoft.Json;
 using Server.Configurations;
 using Server.Data;
+using Server.Helpers;
 using Server.Models;
 using Server.Services;
 
@@ -82,8 +83,11 @@ builder.Services.AddAuthorization();
 builder.Services.AddAutoMapper(typeof(MapperInitializer));
 
 builder.Services.AddScoped<ICountryManagementService, CountryManagementService>();
+
 builder.Services.AddScoped<IDateTimeService, DateTimeService>();
 
+builder.Services.AddScoped<ISortHelper<Country>, SortHelper<Country>>();
+
 // Adding DB Context with PostgreSQL
 var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
 builder.Services.AddDbContext<ApplicationDbContext>(options =>

Server/Server.csproj

@@ -27,6 +27,7 @@
         <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="6.0.7" />
         <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
         <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="6.23.1" />
+        <PackageReference Include="System.Linq.Dynamic.Core" Version="1.2.20" />
     </ItemGroup>
 
     <ItemGroup>

Server/Services/CountryManagementService.cs

@@ -1,7 +1,9 @@
+using System.Linq.Dynamic.Core;
 using AutoMapper;
 using AutoMapper.QueryableExtensions;
 using Microsoft.EntityFrameworkCore;
 using Server.Data;
+using Server.Helpers;
 using Server.Models;
 using SharedModels.DataTransferObjects;
 using SharedModels.QueryStringParameters;
@@ -12,12 +14,14 @@ public class CountryManagementService : ICountryManagementService
 {
     private readonly ApplicationDbContext _dbContext;
     private readonly IMapper _mapper;
+    private readonly ISortHelper<Country> _countrySortHelper;
 
     public CountryManagementService(ApplicationDbContext dbContext,
-        IMapper mapper)
+        IMapper mapper, ISortHelper<Country> countrySortHelper)
     {
         _dbContext = dbContext;
         _mapper = mapper;
+        _countrySortHelper = countrySortHelper;
     }
 
     public async Task<(bool isSucceed, string message, CountryDto country)> AddCountry(CreateCountryDto createCountryDto)
@@ -36,14 +40,27 @@ public class CountryManagementService : ICountryManagementService
         var dbCountries = _dbContext.Countries.AsQueryable();
         
         SearchByAllCountryFields(ref dbCountries, parameters.Search);
-        SearchByCountryCode(ref dbCountries, parameters.CountryCode);
-        SearchByCountryName(ref dbCountries, parameters.CountryName);
+        SearchByCountryCode(ref dbCountries, parameters.Code);
+        SearchByCountryName(ref dbCountries, parameters.Name);
+
+        try
+        {
+            dbCountries = _countrySortHelper.ApplySort(dbCountries, parameters.Sort);
+            
+            // By calling Any() we will check if LINQ to Entities Query will be
+            // executed. If not it will throw an InvalidOperationException exception
+            var isExecuted = dbCountries.Any();
+        }
+        catch (Exception e)
+        {
+            return (false, "Invalid sorting string", null, null)!;
+        }
 
         var pagingMetadata = ApplyPaging(ref dbCountries, parameters.PageNumber,
             parameters.PageSize);
 
-        var countryDtos = dbCountries.ToList()
-            .ConvertAll(c => _mapper.Map<CountryDto>(c));
+        var countryDtos =
+            dbCountries.ProjectTo<CountryDto>(_mapper.ConfigurationProvider);
         
         return (true, "", countryDtos, pagingMetadata);
 

SharedModels/QueryStringParameters/CountryParameters.cs

@@ -2,6 +2,11 @@ namespace SharedModels.QueryStringParameters;
 
 public class CountryParameters : QueryStringParameters
 {
-    public string? CountryCode { get; set; }
-    public string? CountryName { get; set; }
+    public CountryParameters()
+    {
+        Sort = "id";
+    }
+    
+    public string? Code { get; set; }
+    public string? Name { get; set; }
 }

SharedModels/QueryStringParameters/QueryStringParameters.cs

@@ -13,4 +13,5 @@ public class QueryStringParameters
     }
     
     public string? Search { get; set; }
+    public string? Sort { get; set; }
 }