Add Pagination

Author: Asylgareev Rustam

src/SmartHead.Essentials.Application/Controller/ApiControllerBase.cs

@@ -6,28 +6,24 @@ namespace SmartHead.Essentials.Application.Controller
 {
     [ApiController]
     [Route("api/[controller]")]
+    [ProducesErrorResponseType(typeof(void))]
     public abstract class FormattedApiControllerBase : ControllerBase
     {
         [NonAction]
         public BadRequestObjectResult BadRequest(string subStatus)
             => BadRequest(subStatus, null);
-
         [NonAction]
         public override BadRequestObjectResult BadRequest(object error)
             => BadRequest("SomethingWentWrong", error);
-
         [NonAction]
         public override BadRequestObjectResult BadRequest(ModelStateDictionary modelState)
             => InvalidModelStateResponseFactory.CreateFrom("InvalidModel", modelState);
-
         [NonAction]
         public BadRequestObjectResult BadRequest(string subStatus, object errorContent, string debugData = null)
             => new BadRequestObjectResult(new ErrorApiResponse(subStatus, errorContent, debugData));
-
         [NonAction]
         public OkObjectResult Ok(object content, string debugData = null)
             => new OkObjectResult(new SuccessApiResponse(content, debugData));
-
         [NonAction]
         public CreatedAtRouteResult CreatedAt(object routeValues, object content, string debugData = null)
             => new CreatedAtRouteResult(routeValues, new SuccessApiResponse(content, debugData));

src/SmartHead.Essentials.Application/Pagination/PagedEnumerable.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+
+namespace SmartHead.Essentials.Application.Pagination
+{
+    public class PagedEnumerable<T>
+    {
+        public PagedEnumerable(IEnumerable<T> items, PaginationModel pagination)
+        {
+            Items = items ?? throw new ArgumentNullException(nameof(items));
+            Pagination = pagination ?? throw new ArgumentNullException(nameof(pagination));
+        }
+
+        public PaginationModel Pagination { get; set; }
+        public IEnumerable<T> Items { get; set; }
+    }
+}

src/SmartHead.Essentials.Application/Pagination/PaginationModel.cs

@@ -0,0 +1,24 @@
+using System;
+
+namespace SmartHead.Essentials.Application.Pagination
+{
+    public class PaginationModel
+    {
+        public PaginationModel(int count, int size, int page = 1)
+        {
+            PageNumber = page;
+            TotalPages = (int)Math.Ceiling(count / (double)size);
+            PageSize = size;
+        }
+
+        public int PageNumber { get; }
+
+        public int TotalPages { get; }
+
+        public int PageSize { get; }
+
+        public bool HasPreviousPage => PageNumber > 1;
+
+        public bool HasNextPage => PageNumber < TotalPages;
+    }
+}

src/SmartHead.Essentials.Application/Pagination/QueryModel.cs

@@ -0,0 +1,10 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace SmartHead.Essentials.Application.Pagination
+{
+    public class QueryModel
+    {
+        [Required]
+        public int Page { get; set; } = 1;
+    }
+}

src/SmartHead.Essentials.Application/SmartHead.Essentials.Application.csproj

@@ -7,7 +7,7 @@
     <IsPackable>true</IsPackable>
     <Authors>Rustam Asylgareev</Authors>
     <PackageProjectUrl>https://github.com/smarthead-dev/SmartHead.Essentials</PackageProjectUrl>
-    <Version>0.0.4</Version>
+    <Version>0.0.5</Version>
     <Company>SmartHead</Company>
     <IsTestProject>false</IsTestProject>
     <Description>SmartHead.Essentials.Application</Description>

src/SmartHead.Essentials.Extensions/EnumerableExtensions.cs

@@ -0,0 +1,25 @@
+using System.Linq;
+using SmartHead.Essentials.Application.Pagination;
+
+namespace SmartHead.Essentials.Extensions
+{
+    public static class EnumerableExtensions
+    {
+        public static PagedEnumerable<TModel> GetPage<TModel>(
+            this IQueryable<TModel> query,
+            int page = 1,
+            int size = 10)
+        {
+            if (page < 1) page = 1;
+            if (size < 1) size = 10;
+
+            var paginatedQueryable = query
+                .Skip((page - 1) * size)
+                .Take(size);
+
+            var paginationModel = new PaginationModel(query.Count(), size, page);
+
+            return new PagedEnumerable<TModel>(paginatedQueryable, paginationModel);
+        }
+    }
+}

src/SmartHead.Essentials.Extensions/SmartHead.Essentials.Extensions.csproj

@@ -6,7 +6,7 @@
     <IsPackable>true</IsPackable>
     <Authors>Rustam Asylgareev</Authors>
     <PackageProjectUrl>https://github.com/smarthead-dev/SmartHead.Essentials</PackageProjectUrl>
-    <Version>0.0.2</Version>
+    <Version>0.0.3</Version>
     <Company>SmartHead</Company>
     <IsTestProject>false</IsTestProject>
     <Description>SmartHead.Essentials.Extensions</Description>
@@ -18,4 +18,8 @@
     <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.1" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\SmartHead.Essentials.Application\SmartHead.Essentials.Application.csproj" />
+  </ItemGroup>
+
 </Project>