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Chris Santero
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add pagination transformer
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Lines changed: 278 additions & 1 deletion

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‎JSONAPI.Tests/ActionFilters/DefaultPaginationTransformerTests.cs‎

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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Net;
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using System.Net.Http;
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using System.Web.Http;
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using FluentAssertions;
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using JSONAPI.ActionFilters;
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using JSONAPI.Core;
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using Microsoft.VisualStudio.TestTools.UnitTesting;
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namespace JSONAPI.Tests.ActionFilters
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{
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[TestClass]
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public class DefaultPaginationTransformerTests
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{
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private class Dummy
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{
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// ReSharper disable UnusedAutoPropertyAccessor.Local
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public string Id { get; set; }
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// ReSharper restore UnusedAutoPropertyAccessor.Local
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public string FirstName { get; set; }
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public string LastName { get; set; }
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}
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private IList<Dummy> _fixtures;
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private IQueryable<Dummy> _fixturesQuery;
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[TestInitialize]
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public void SetupFixtures()
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{
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_fixtures = new List<Dummy>
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{
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new Dummy { Id = "1", FirstName = "Thomas", LastName = "Paine" },
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new Dummy { Id = "2", FirstName = "Samuel", LastName = "Adams" },
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new Dummy { Id = "3", FirstName = "George", LastName = "Washington"},
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new Dummy { Id = "4", FirstName = "Thomas", LastName = "Jefferson" },
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new Dummy { Id = "5", FirstName = "Martha", LastName = "Washington"},
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new Dummy { Id = "6", FirstName = "Abraham", LastName = "Lincoln" },
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new Dummy { Id = "7", FirstName = "Andrew", LastName = "Jackson" },
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new Dummy { Id = "8", FirstName = "Andrew", LastName = "Johnson" },
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new Dummy { Id = "9", FirstName = "William", LastName = "Harrison" }
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};
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_fixturesQuery = _fixtures.AsQueryable();
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}
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private DefaultPaginationTransformer GetTransformer(int maxPageSize)
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{
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return new DefaultPaginationTransformer("page.number", "page.size", maxPageSize);
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}
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private Dummy[] GetArray(string uri, int maxPageSize = 50)
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{
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var request = new HttpRequestMessage(HttpMethod.Get, uri);
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return GetTransformer(maxPageSize).ApplyPagination(_fixturesQuery, request).ToArray();
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}
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[TestMethod]
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public void ApplyPagination_has_no_effect_when_no_paging_parameters_are_supplied()
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{
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var array = GetArray("http://api.example.com/dummies");
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array.Length.Should().Be(9);
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}
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[TestMethod]
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public void ApplyPagination_returns_all_results_when_they_are_within_page()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=0&page[size]=10");
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array.Length.Should().Be(9);
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}
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[TestMethod]
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public void ApplyPagination_returns_no_results_when_page_size_is_zero()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=0&page[size]=0");
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array.Length.Should().Be(0);
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}
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[TestMethod]
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public void ApplyPagination_returns_first_page_of_data()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=0&page[size]=4");
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array.Should().BeEquivalentTo(_fixtures[0], _fixtures[1], _fixtures[2], _fixtures[3]);
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}
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[TestMethod]
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public void ApplyPagination_returns_second_page_of_data()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=1&page[size]=4");
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array.Should().BeEquivalentTo(_fixtures[4], _fixtures[5], _fixtures[6], _fixtures[7]);
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}
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[TestMethod]
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public void ApplyPagination_returns_page_at_end()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=2&page[size]=4");
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array.Should().BeEquivalentTo(_fixtures[8]);
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}
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[TestMethod]
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public void ApplyPagination_returns_nothing_for_page_after_end()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=3&page[size]=4");
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array.Length.Should().Be(0);
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}
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[TestMethod]
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public void ApplyPagination_uses_max_page_size_when_requested_page_size_is_higher()
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{
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var array = GetArray("http://api.example.com/dummies?page[number]=1&page[size]=8", 3);
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array.Should().BeEquivalentTo(_fixtures[3], _fixtures[4], _fixtures[5]);
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}
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[TestMethod]
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public void ApplyPagination_returns_400_if_page_number_is_negative()
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{
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Action action = () =>
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{
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GetArray("http://api.example.com/dummies?page[number]=-4&page[size]=4");
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};
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action.ShouldThrow<HttpResponseException>().And.Response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
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}
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[TestMethod]
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public void ApplyPagination_returns_400_if_page_size_is_negative()
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{
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Action action = () =>
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{
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GetArray("http://api.example.com/dummies?page[number]=0&page[size]=-4");
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};
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action.ShouldThrow<HttpResponseException>().And.Response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
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}
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[TestMethod]
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public void ApplyPagination_returns_400_if_page_number_specified_but_not_size()
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{
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Action action = () =>
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{
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GetArray("http://api.example.com/dummies?page[number]=0");
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};
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action.ShouldThrow<HttpResponseException>().And.Response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
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}
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[TestMethod]
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public void ApplyPagination_returns_400_if_page_size_specified_but_not_number()
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{
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Action action = () =>
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{
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GetArray("http://api.example.com/dummies?page[size]=0");
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};
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action.ShouldThrow<HttpResponseException>().And.Response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
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}
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[TestMethod]
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public void DefaultPaginationTransformer_cannot_be_instantiated_if_max_page_size_is_zero()
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{
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Action action = () =>
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{
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GetTransformer(0);
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};
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action.ShouldThrow<ArgumentOutOfRangeException>();
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}
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[TestMethod]
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public void DefaultPaginationTransformer_cannot_be_instantiated_if_max_page_size_is_negative()
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{
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Action action = () =>
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{
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GetTransformer(-4);
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};
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action.ShouldThrow<ArgumentOutOfRangeException>();
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}
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}
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}

‎JSONAPI.Tests/JSONAPI.Tests.csproj‎

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@@ -79,6 +79,7 @@
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</CodeAnalysisDependentAssemblyPaths>
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</ItemGroup>
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<ItemGroup>
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<Compile Include="ActionFilters\DefaultPaginationTransformerTests.cs" />
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<Compile Include="ActionFilters\QueryableTransformerTestsBase.cs" />
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<Compile Include="ActionFilters\DefaultSortingTransformerTests.cs" />
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<Compile Include="ActionFilters\DefaultFilteringTransformerTests.cs" />

‎JSONAPI/ActionFilters/DefaultPaginationTransformer.cs‎

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using System;
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using System.Linq;
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using System.Net;
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using System.Net.Http;
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using System.Web.Http;
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namespace JSONAPI.ActionFilters
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{
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/// <summary>
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/// Performs pagination a
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/// </summary>
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public class DefaultPaginationTransformer : IQueryablePaginationTransformer
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{
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private const int DefaultPageSize = 100;
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private readonly string _pageNumberQueryParam;
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private readonly string _pageSizeQueryParam;
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private readonly int? _maxPageSize;
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/// <summary>
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/// Creates a DefaultPaginationTransformer
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/// </summary>
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/// <param name="pageNumberQueryParam">The query parameter to use to indicate the page number</param>
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/// <param name="pageSizeQueryParam">The query parameter to use to indicate the page size</param>
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/// <param name="maxPageSize">The maximum page size to allow clients to request. Leave null for no restriction.</param>
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public DefaultPaginationTransformer(string pageNumberQueryParam, string pageSizeQueryParam, int? maxPageSize = null)
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{
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if (maxPageSize <= 0) throw new ArgumentOutOfRangeException("maxPageSize", "The maximum page size must be 1 or greater.");
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_pageNumberQueryParam = pageNumberQueryParam;
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_pageSizeQueryParam = pageSizeQueryParam;
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_maxPageSize = maxPageSize;
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}
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public IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage request)
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{
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var hasPageNumberParam = false;
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var hasPageSizeParam = false;
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var pageNumber = 0;
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var pageSize = _maxPageSize ?? DefaultPageSize;
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foreach (var kvp in request.GetQueryNameValuePairs())
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{
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if (kvp.Key == _pageNumberQueryParam)
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{
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hasPageNumberParam = true;
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if (!int.TryParse(kvp.Value, out pageNumber)) throw new HttpResponseException(HttpStatusCode.BadRequest);
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}
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else if (kvp.Key == _pageSizeQueryParam)
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{
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hasPageSizeParam = true;
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if (!int.TryParse(kvp.Value, out pageSize)) throw new HttpResponseException(HttpStatusCode.BadRequest);
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}
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}
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if (!hasPageNumberParam && !hasPageSizeParam)
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return query;
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if ((hasPageNumberParam && !hasPageSizeParam) || (!hasPageNumberParam && hasPageSizeParam))
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throw new HttpResponseException(HttpStatusCode.BadRequest);
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if (pageNumber < 0 || pageSize < 0)
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throw new HttpResponseException(HttpStatusCode.BadRequest);
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if (_maxPageSize != null && pageSize > _maxPageSize.Value)
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pageSize = _maxPageSize.Value;
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var skip = pageNumber * pageSize;
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return query.Skip(skip).Take(pageSize);
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}
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}
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}

‎JSONAPI/ActionFilters/IQueryablePaginationTransformer.cs‎

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using System.Linq;
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using System.Net.Http;
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namespace JSONAPI.ActionFilters
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{
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/// <summary>
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/// Provides a service to provide a page of data based on information from the request.
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/// </summary>
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public interface IQueryablePaginationTransformer
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{
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/// <summary>
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/// Pages the query according to information from the request.
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/// </summary>
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/// <param name="query">The query to page</param>
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/// <param name="request">The request message</param>
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/// <typeparam name="T">The queryable element type</typeparam>
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/// <returns>An IQueryable configured to return a page of data</returns>
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IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage request);
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}
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}

‎JSONAPI/ActionFilters/JsonApiQueryableAttribute.cs‎

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private readonly IQueryableEnumerationTransformer _enumerationTransformer;
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private readonly IQueryableFilteringTransformer _filteringTransformer;
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private readonly IQueryableSortingTransformer _sortingTransformer;
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private readonly IQueryablePaginationTransformer _paginationTransformer;
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/// <summary>
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/// Creates a new JsonApiQueryableAttribute.
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/// </summary>
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/// <param name="enumerationTransformer">The transform to be used for enumerating IQueryable payloads.</param>
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/// <param name="filteringTransformer">The transform to be used for filtering IQueryable payloads</param>
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/// <param name="sortingTransformer">The transform to be used for sorting IQueryable payloads.</param>
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/// <param name="paginationTransformer">The transform to be used for pagination of IQueryable payloads.</param>
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public JsonApiQueryableAttribute(
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IQueryableEnumerationTransformer enumerationTransformer,
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IQueryableFilteringTransformer filteringTransformer = null,
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IQueryableSortingTransformer sortingTransformer = null)
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IQueryableSortingTransformer sortingTransformer = null,
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IQueryablePaginationTransformer paginationTransformer = null)
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{
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_sortingTransformer = sortingTransformer;
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_paginationTransformer = paginationTransformer;
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_enumerationTransformer = enumerationTransformer;
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_filteringTransformer = filteringTransformer;
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}
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if (_sortingTransformer != null)
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query = _sortingTransformer.Sort(query, request);
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105+
if (_paginationTransformer != null)
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query = _paginationTransformer.ApplyPagination(query, request);
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return await _enumerationTransformer.Enumerate(query, cancellationToken);
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}
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}

‎JSONAPI/JSONAPI.csproj‎

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</ItemGroup>
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<ItemGroup>
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<Compile Include="ActionFilters\DefaultFilteringTransformer.cs" />
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<Compile Include="ActionFilters\DefaultPaginationTransformer.cs" />
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<Compile Include="ActionFilters\IQueryableEnumerationTransformer.cs" />
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<Compile Include="ActionFilters\IQueryableFilteringTransformer.cs" />
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<Compile Include="ActionFilters\IQueryablePaginationTransformer.cs" />
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<Compile Include="ActionFilters\IQueryableSortingTransformer.cs" />
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<Compile Include="ActionFilters\JsonApiQueryableAttribute.cs" />
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<Compile Include="ActionFilters\QueryableTransformException.cs" />

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