zenstruck/porpaginas

Library that generically solves several pagination issues with DAO/repository abstractions.

v2.0.0 2018-02-08 13:23 UTC

README

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NOTE: This library is a fork of beberlei/porpaginas.

This library solves a bunch of issues that comes up with APIs of Repository classes alot:

  • You need different methods for paginatable and non-paginatable finder methods.
  • You need to expose the underlying data-source and return query objects from your repository.
  • Serialization of paginators should be easily possible for REST APIs

Both Pagerfanta and KnpLabs Pager don't solve this issue and their APIs are really problematic in this regard. You need to return the query objects or adapters for paginators from your repositories to get it working and then use an API on the controller side to turn them into a paginated result set.

Porpaginas solves this by introducing a sane abstraction for paginated results. For rendering purposes you can integrate with either Pagerfanta or KnpLabs Pager, this library is not about reimplementating the view part of pagination.

Central part of this library is the interface Result:

namespace Zenstruck\Porpaginas;

interface Result extends \Countable, \IteratorAggregate, \JsonSerializable
{
    public function take(int $offset, int $limit): Page;

    /**
     * Return the number of all results in the paginatable.
     */
    public function count(): int;

    /**
     * Return an iterator over all results of the paginatable.
     */
    public function getIterator(): \Iterator;
}

This API offers you two ways to iterate over the paginatable result, either the full result or a paginated window of the result using take(). One drawback is that the query is always lazily executed inside the Result and not directly in the repository.

The Page interface returned from Result::take() looks like this:

namespace Zenstruck\Porpaginas;

interface Page extends \Countable, \IteratorAggregate, \JsonSerializable
{
    /**
     * Return the number of results on the currrent page.
     */
    public function count(): int;

    /**
     * Return the number of ALL results in the paginatable..
     */
    public function totalCount(): int;

    /**
     * Return an iterator over selected windows of results of the paginatable.
     */
    public function getIterator(): \Iterator;
}

Supported Backends

  • Array
  • Doctrine ORM
  • Doctrine DBAL

Example

Take the following example using Doctrine ORM:

use Zenstruck\Porpaginas\Result;

class UserRepository extends EntityRepository
{
    public function findAllUsers(): Result
    {
        $qb = $this->createQueryBuilder('u')->orderBy('u.username');

        return new ORMQueryResult($qb);
    }
}

class UserController
{
    /**
     * @var UserRepository
     */
    private $userRepository;

    public function listAction(Request $request)
    {
        $result = $this->userRepository->findAllUsers();
        // no filtering by page, iterate full result

        return array('users' => $result);
    }

    public function porpaginasListAction(Request $request)
    {
        $result = $this->userRepository->findAllUsers();

        $paginator = $result->take(($request->get('page', 1)-1) * 20, 20);

        return array('users' => $paginator);
    }
}

This library also comes with Pager helpers. Using the ResultPager, the above controller's porpaginasListAction() could be re-written as follows:

use Zenstruck\Porpaginas\Pager\ResultPager;

class UserController
{
    /**
     * @var UserRepository
     */
    private $userRepository;

    public function porpaginasListAction(Request $request)
    {
        $result = $this->userRepository->findAllUsers();

        $pager = new ResultPager($result, $request->get('page', 1);

        return array('users' => $pager);
    }
}