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Chris Santero
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change pagination transformer to return rich object
This change allows the pagination transformer to communicate information about the pagination operation that was performed, in addition to the paged query itself. This paves the way for including page links at the top level.
1 parent 080cc88 commit 70e220a

6 files changed

Lines changed: 67 additions & 8 deletions

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‎JSONAPI.Tests/ActionFilters/DefaultPaginationTransformerTests.cs‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -54,7 +54,7 @@ private DefaultPaginationTransformer GetTransformer(int maxPageSize)
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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);
57-
return GetTransformer(maxPageSize).ApplyPagination(_fixturesQuery, request).ToArray();
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return GetTransformer(maxPageSize).ApplyPagination(_fixturesQuery, request).PagedQuery.ToArray();
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}
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6060
[TestMethod]

‎JSONAPI/ActionFilters/DefaultPaginationTransformResult.cs‎

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
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using System.Linq;
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namespace JSONAPI.ActionFilters
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{
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/// <summary>
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/// Default implementation of IPaginationTransformResult`1
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/// </summary>
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/// <typeparam name="T"></typeparam>
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public class DefaultPaginationTransformResult<T> : IPaginationTransformResult<T>
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{
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public IQueryable<T> PagedQuery { get; set; }
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public bool PaginationWasApplied { get; set; }
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public int PageNumber { get; set; }
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public int PageSize { get; set; }
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}
16+
}

‎JSONAPI/ActionFilters/DefaultPaginationTransformer.cs‎

Lines changed: 16 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
namespace JSONAPI.ActionFilters
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{
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/// <summary>
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/// Performs pagination a
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/// Performs pagination
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/// </summary>
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public class DefaultPaginationTransformer : IQueryablePaginationTransformer
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{
@@ -32,7 +32,7 @@ public DefaultPaginationTransformer(string pageNumberQueryParam, string pageSize
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_maxPageSize = maxPageSize;
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}
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35-
public IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage request)
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public IPaginationTransformResult<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;
@@ -58,7 +58,13 @@ public IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage
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}
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6060
if (!hasPageNumberParam && !hasPageSizeParam)
61-
return query;
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{
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return new DefaultPaginationTransformResult<T>
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{
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PagedQuery = query,
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PaginationWasApplied = false
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};
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}
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if ((hasPageNumberParam && !hasPageSizeParam) || (!hasPageNumberParam && hasPageSizeParam))
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throw new QueryableTransformException(
@@ -77,7 +83,13 @@ public IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage
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pageSize = _maxPageSize.Value;
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var skip = pageNumber * pageSize;
80-
return query.Skip(skip).Take(pageSize);
86+
return new DefaultPaginationTransformResult<T>
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{
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PageNumber = pageNumber,
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PageSize = pageSize,
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PagedQuery = query.Skip(skip).Take(pageSize),
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PaginationWasApplied = true
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};
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}
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}
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}

‎JSONAPI/ActionFilters/IQueryablePaginationTransformer.cs‎

Lines changed: 29 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,34 @@ public interface IQueryablePaginationTransformer
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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>
18-
IQueryable<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage request);
17+
/// <returns>The result of pagination</returns>
18+
IPaginationTransformResult<T> ApplyPagination<T>(IQueryable<T> query, HttpRequestMessage request);
19+
}
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21+
/// <summary>
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/// The result of a pagination transform
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/// </summary>
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/// <typeparam name="T"></typeparam>
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public interface IPaginationTransformResult<out T>
26+
{
27+
/// <summary>
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/// A query that has been paginated
29+
/// </summary>
30+
IQueryable<T> PagedQuery { get; }
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32+
/// <summary>
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/// Whether the query has been paginated or not
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/// </summary>
35+
bool PaginationWasApplied { get; }
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37+
/// <summary>
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/// The current page of the query
39+
/// </summary>
40+
int PageNumber { get; }
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42+
/// <summary>
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/// The size of this page of data
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/// </summary>
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int PageSize { get; }
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}
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}

‎JSONAPI/JSONAPI.csproj‎

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Original file line numberDiff line numberDiff line change
@@ -68,6 +68,7 @@
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<ItemGroup>
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<Compile Include="ActionFilters\DefaultFilteringTransformer.cs" />
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<Compile Include="ActionFilters\DefaultPaginationTransformer.cs" />
71+
<Compile Include="ActionFilters\DefaultPaginationTransformResult.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" />

‎JSONAPI/Payload/DefaultQueryablePayloadBuilder.cs‎

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -45,7 +45,10 @@ public async Task<IPayload> BuildPayload<T>(IQueryable<T> query, HttpRequestMess
4545
query = _sortingTransformer.Sort(query, request);
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4747
if (_paginationTransformer != null)
48-
query = _paginationTransformer.ApplyPagination(query, request);
48+
{
49+
var paginationResults = _paginationTransformer.ApplyPagination(query, request);
50+
query = paginationResults.PagedQuery;
51+
}
4952

5053
var results = await _enumerationTransformer.Enumerate(query, cancellationToken);
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