public override async Task<PagedResultDto<BookDto>> GetListAsync(
PagedAndSortedResultRequestDto input)
public override async Task<PagedResultDto<BookDto>> GetListAsync(PagedAndSortedResultRequestDto input)
{
await CheckGetListPolicyAsync();
//Get the IQueryable<Book> from the repository
var queryable = await Repository.GetQueryableAsync();
//Prepare a query to join books and authors
var query = from book in Repository
var query = from book in queryable
join author in _authorRepository on book.AuthorId equals author.Id
orderby input.Sorting
orderby input.Sorting //TODO: Can not sort like that!
select new {book, author};
//Paging
query = query
.Skip(input.SkipCount)
.Take(input.MaxResultCount);
@ -437,7 +439,7 @@ Let's see the changes we've done:
* Injected `IAuthorRepository` to query from the authors.
* Overrode the `GetAsync` method of the base `CrudAppService`, which returns a single `BookDto` object with the given `id`.
* Used a simple LINQ expression to join books and authors and query them together for the given book id.
* Used `AsyncExecuter.FirstOrDefaultAsync(...)` to execute the query and get a result. `AsyncExecuter` was previously used in the `AuthorAppService`. Check the [repository documentation](../Repositories.md) to understand why we've used it.
* Used `AsyncExecuter.FirstOrDefaultAsync(...)` to execute the query and get a result. It is a way to use asynchronous LINQ extensions without depending on the database provider API. Check the [repository documentation](../Repositories.md) to understand why we've used it.
* Throws an `EntityNotFoundException` which results an `HTTP 404` (not found) result if requested book was not present in the database.
* Finally, created a `BookDto` object using the `ObjectMapper`, then assigning the `AuthorName` manually.
* Overrode the `GetListAsync` method of the base `CrudAppService`, which returns a list of books. The logic is similar to the previous method, so you can easily understand the code.
@ -230,12 +231,10 @@ public async Task<PagedResultDto<AuthorDto>> GetListAsync(GetAuthorListDto input
input.Filter
);
var totalCount = await AsyncExecuter.CountAsync(
_authorRepository.WhereIf(
!input.Filter.IsNullOrWhiteSpace(),
author => author.Name.Contains(input.Filter)
)
);
var totalCount = input.Filter == null
? await _authorRepository.CountAsync()
: await _authorRepository.CountAsync(
author => author.Name.Contains(input.Filter));
return new PagedResultDto<AuthorDto>(
totalCount,
@ -246,7 +245,7 @@ public async Task<PagedResultDto<AuthorDto>> GetListAsync(GetAuthorListDto input
* Default sorting is "by author name" which is done in the beginning of the method in case of it wasn't sent by the client.
* Used the `IAuthorRepository.GetListAsync` to get a paged, sorted and filtered list of authors from the database. We had implemented it in the previous part of this tutorial. Again, it actually was not needed to create such a method since we could directly query over the repository, but wanted to demonstrate how to create custom repository methods.
* Directly queried from the `AuthorRepository` while getting the count of the authors. We preferred to use the `AsyncExecuter` service which allows us to perform async queries without depending on the EF Core. However, you could depend on the EF Core package and directly use the `_authorRepository.WhereIf(...).ToListAsync()` method. See the [repository document](../Repositories.md) to read the alternative approaches and the discussion.
* Directly queried from the `AuthorRepository` while getting the count of the authors. If a filter is sent, then we are using it to filter entities while getting the count.
* Finally, returning a paged result by mapping the list of `Author`s to a list of `AuthorDto`s.
Halil İbrahim Kalkan
4 years ago