Initial commit

.eproject

+:project-name "HAB Solr"

.gitignore

+# GNU Emacs
+*~
+.*~
+\#*
+.\#*
+ChangeLog
+
+# Composer
+/vendor/
+composer.lock

composer.json

+{
+    "name": "hab/solr",
+    "autoload": {
+        "psr-0": {
+            "HAB": "src/"
+        }
+    }
+}

src/HAB/Solr/Command/CommandInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Command;
+
+/**
+ * Interface of a Solr command.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface CommandInterface
+{
+    /**
+     * Return handler.
+     *
+     * @return string
+     */
+    public function getHandler ();
+
+    /**
+     * Return parameters.
+     *
+     * @return array
+     */
+    public function getParameters ();
+
+    /**
+     * Set Solr response.
+     *
+     * @param  string $response
+     * @return void
+     */
+    public function setResponse ($response);
+
+    /**
+     * Return command result.
+     *
+     * @return mixed
+     */
+    public function getResult ();
+        
+}
\ No newline at end of file

src/HAB/Solr/Command/Invoker.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Command;
+
+use HAB\Solr\ParamBag;
+
+use GuzzleHttp\Client;
+
+/**
+ * Solr command invoker.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class Invoker
+{
+    /**
+     * Base Url.
+     *
+     * @var string
+     */
+    private $baseUrl;
+
+    /**
+     * Client.
+     *
+     * @var Client
+     */
+    private $client;
+
+    /**
+     * Parameter provider.
+     *
+     * @var ParamBag
+     */
+    private $parameters;
+
+    public function __construct ($baseUrl, Client $client)
+    {
+        $this->baseUrl = $baseUrl;
+        $this->client = $client;
+    }
+
+    /**
+     * Invoke command.
+     *
+     * @param  CommandInterface $command
+     * @param  ParamBag         $parameters
+     * @return mixed
+     */
+    public function invoke (CommandInterface $command, ParamBag $parameters = null)
+    {
+        $params = $this->getParameters();
+        if ($parameters) {
+            $params->mergeWith($parameters);
+        }
+
+        $query = $params->mergeWith($command->getParameters())->request();
+        $url = sprintf('%s/%s?%s', $this->baseUrl, $command->getHandler(), implode('&', $query));
+
+        $response = $this->getClient()->request('GET', $url);
+
+        $command->setResponse($response->getBody());
+        return $command->getResult();
+    }
+
+    /**
+     * Return client.
+     *
+     * @return Client
+     */
+    public function getClient ()
+    {
+        return $this->client;
+    }
+
+    /**
+     * Return parameters.
+     *
+     * @return ParamBag
+     */
+    public function getParameters ()
+    {
+        if (is_null($this->parameters)) {
+            $this->setParameters(new ParamBag());
+        }
+        return $this->parameters;
+    }
+
+    /**
+     * Set parameters.
+     *
+     * @param  ParamBag $parameters
+     * @return
+     */
+    public function setParameters (ParamBag $parameters)
+    {
+        $this->parameters = $parameters;
+    }
+
+    /**
+     * Encode key-value-pair.
+     *
+     * @param  string $name
+     * @param  string $value
+     * @return string
+     */
+    private static function encode ($name, $value)
+    {
+        return sprintf('%s=%s', urlencode($name), urlencode($value));
+    }
+}
\ No newline at end of file

src/HAB/Solr/Command/QueryBuilderInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Command;
+
+use HAB\Solr\ParamBag;
+
+/**
+ * Interface of a Solr query builder.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface QueryBuilderInterface
+{
+    /**
+     * Return Solr query parameters.
+     *
+     * @param  array|\ArrayAccess $query
+     * @return ParamBag
+     */
+    public function buildQuery ($query);
+}
\ No newline at end of file

src/HAB/Solr/Command/Search.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Command;
+
+use HAB\Solr\Response\Json\RecordCollection;
+use HAB\Solr\ParamBag;
+
+use ArrayObject;
+use LogicException;
+use RuntimeException;
+
+/**
+ * Search command.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class Search implements CommandInterface
+{
+    /**
+     * Handler.
+     *
+     * @var string
+     */
+    private $handler;
+
+    /**
+     * Query.
+     *
+     * @var ArrayObject
+     */
+    private $query;
+
+    /**
+     * Query builder.
+     *
+     * @var QueryBuilderInterface
+     */
+    private $builder;
+
+    public function __construct ($handler, QueryBuilderInterface $builder)
+    {
+        $this->handler = $handler;
+        $this->builder = $builder;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getHandler ()
+    {
+        return $this->handler;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getParameters ()
+    {
+        return $this->builder->buildQuery($this->query);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setResponse ($response)
+    {
+        $result = json_decode($response, true);
+        if (!is_array($result)) {
+            throw new RuntimeException('Invalid response from upstream server');
+        }
+        $this->result = new RecordCollection($result);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getResult ()
+    {
+        if (!$this->result instanceof RecordCollection) {
+            throw new LogicException('Command was not executed');
+        }
+        return $this->result;
+    }
+
+    public function setQuery (ArrayObject $query)
+    {
+        $this->query = $query;
+    }
+
+    public function getQuery ()
+    {
+        if (is_null($this->query)) {
+            $this->setQuery(new ArrayObject());
+        }
+        return $this->query;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/AbstractFacetAdapter.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet;
+
+use Symfony\Component\HttpFoundation\ParameterBag;
+
+/**
+ * An abstract base class for facet adapters.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+abstract class AbstractFacetAdapter implements FacetAdapterInterface
+{
+    /**
+     * The facet value container.
+     *
+     * @var Value\Container\ContainerInterface
+     */
+    private $container;
+
+    /**
+     * Facet name.
+     *
+     * @var string
+     */
+    private $name;
+
+    /**
+     * Facet label, if any.
+     *
+     * @var string
+     */
+    private $label;
+
+    /**
+     * The request value mapper.
+     *
+     * @var ValueMapper\RequestValueMapperInterface
+     */
+    private $mapper;
+
+    /**
+     * Container sort function.
+     *
+     * @var callable
+     */
+    private $sort;
+
+    /**
+     * Application state.
+     *
+     * @var ParameterBag
+     */
+    private $state;
+
+    /**
+     * Set sort function.
+     *
+     * The sort function is called with the facet value container as
+     * sole argument.
+     *
+     * @param  callable $sort
+     * @return void
+     */
+    public function setSortFunction ($sort)
+    {
+        $this->sort = $sort;
+    }
+
+    /**
+     * Set facet label.
+     *
+     * @param  string $label
+     * @return void
+     */
+    public function setLabel ($label)
+    {
+        $this->label = $label;
+    }
+
+    /**
+     * Return facet label.
+     *
+     * @return string|null
+     */
+    public function getLabel ()
+    {
+        return $this->label ?: $this->getName();
+    }
+
+    /**
+     * Return facet name.
+     *
+     * @return string
+     */
+    public function getName ()
+    {
+        if ($this->name == '') {
+            $this->setName(spl_object_hash($this));
+        }
+        return $this->name;
+    }
+
+    /**
+     * Set the facet name.
+     *
+     * @param  string $name
+     * @return void
+     */
+    public function setName ($name)
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Return facet value container.
+     *
+     * @return Value\Container\ContainerInterface
+     */
+    public function getFacetValueContainer ()
+    {
+        if (!$this->container) {
+            $this->setFacetValueContainer(new Value\Container\FacetValueList());
+        }
+        if ($this->sort) {
+            call_user_func($this->sort, $this->container);
+        }
+        return $this->container;
+    }
+
+    /**
+     * Set facet value container.
+     *
+     * @param  Value\Container\ContainerInterface $container
+     * @return void
+     */
+    public function setFacetValueContainer (Value\Container\ContainerInterface $container)
+    {
+        $this->container = $container;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getRequestValueMapper ()
+    {
+        if (!$this->mapper) {
+            $this->setRequestValueMapper(new ValueMapper\RequestValueIdentityMapper());
+        }
+        return $this->mapper;
+    }
+
+    /**
+     * Set the request value mapper.
+     *
+     * @param  ValueMapper\RequestValueMapperInterface $mapper
+     * @return void
+     */
+    public function setRequestValueMapper (ValueMapper\RequestValueMapperInterface $mapper)
+    {
+        $this->mapper = $mapper;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setComponentState (ParameterBag $state)
+    {
+        $params = $state->get('f');
+        if ($params && is_array($params) && isset($params[$this->getName()])) {
+            $this->setFilterValues($params[$this->getName()]);
+        }
+        $this->state = $state;
+    }
+
+    public function getGlobalComponentState ()
+    {
+        if ($this->state) {
+            return $this->state->all();
+        }
+        return array();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getComponentState ()
+    {
+        return array('f' => array($this->getName() => $this->getFilterValues()));
+    }
+
+    /**
+     * Set filter values from request.
+     *
+     * @param  mixed $values
+     * @return void
+     */
+    abstract public function setFilterValues ($values);
+
+    /**
+     * Return filter values for request.
+     *
+     * @return mixed
+     */
+    abstract public function getFilterValues ();
+}
\ No newline at end of file

src/HAB/Solr/Facet/DefaultFacetAdapter.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet;
+
+use HAB\Solr\Response\Json\RecordCollection;
+
+/**
+ * Default implementation of a {@see FacetAdapterInterface}.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class DefaultFacetAdapter extends AbstractFacetAdapter
+{
+    /**
+     * Decorated facet.
+     *
+     * @var FacetImplInterface
+     */
+    private $facet;
+
+    /**
+     * Facet value label factory.
+     *
+     * @var LabelFactory\LabelFactoryInterface
+     */
+    private $labelFactory;
+
+    /**
+     * Constructor.
+     *
+     * @param  FacetImplInterface $facet
+     * @param  boolean        $sortByLabel
+     * @return void
+     */
+    public function __construct (FacetImplInterface $facet, $sortByLabel = false)
+    {
+        $this->facet = $facet;
+        if ($sortByLabel) {
+            $this->setSortFunction(
+                function (Value\Container\ContainerInterface $container) {
+                    $container->sortByLabel();
+                }
+            );
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setFilterValues ($values)
+    {
+        $this->facet->setSelected(
+            $this->getRequestValueMapper()->mapFromRequest($values)
+        );
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getFilterValues ()
+    {
+        return $this->getRequestValueMapper()->mapToRequest($this->facet->getSelected());
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSearchParameters ()
+    {
+        return $this->facet->getSearchParameters();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setRecordCollection (RecordCollection $response)
+    {
+        $this->facet->setRecordCollection($response);
+        $container = $this->getFacetValueContainer();
+        $factory   = $this->getFacetValueLabelFactory();
+        $selected  = $this->facet->getSelected();
+        $values    = $this->facet->getFacetCounts();
+        $mapper    = $this->getRequestValueMapper();
+        $name      = $this->getName();
+        foreach ($values as $value) {
+            $query = $selected;
+            if ($value->isSelected()) {
+                foreach (array_keys($query, $value->getValue()) as $key) {
+                    unset($query[$key]);
+                }
+            } else {
+                $query []= $value->getValue();
+            }
+            $params = $this->getGlobalComponentState();
+            if ($query) {
+                $params['f'][$name] = $mapper->mapToRequest($query);
+            } else {
+                unset($params['f'][$name]);
+            }
+            $value->setQuery($params);
+            $value->setLabel($factory->createLabel($value->getValue()));
+            $container->addFacetValue($value);
+        }
+    }
+
+    /**
+     * Return facet value label factory.
+     *
+     * @return LabelFactory\LabelFactoryInterface
+     */
+    public function getFacetValueLabelFactory ()
+    {
+        if (!$this->labelFactory) {
+            $this->setFacetValueLabelFactory(new LabelFactory\DefaultLabelFactory());
+        }
+        return $this->labelFactory;
+    }
+
+    /**
+     * Set facet value label factory.
+     *
+     * @param  LabelFactory\LabelFactoryInterface $factory
+     * @return void
+     */
+    public function setFacetValueLabelFactory (LabelFactory\LabelFactoryInterface $factory)
+    {
+        $this->labelFactory = $factory;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/FacetAdapterInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet;
+
+/**
+ * Interface of a facet adapter.
+ *
+ * A facet adapter mitigates between a backend-specific facet
+ * implementation and the rest of the application.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface FacetAdapterInterface
+{
+    /**
+     * Return adapter name.
+     *
+     * @return string
+     */
+    public function getName ();
+
+    /**
+     * Return adapter label.
+     *
+     * @return string
+     */
+    public function getLabel ();
+
+    /**
+     * Return facet value container.
+     *
+     * @return Value\Container\ContainerInterface
+     */
+    public function getFacetValueContainer ();
+
+    /**
+     * Return the request value mapper.
+     *
+     * @return ValueMapper\ValueMapperInterface
+     */
+    public function getRequestValueMapper ();
+}
\ No newline at end of file

src/HAB/Solr/Facet/FacetCollection.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet;
+
+use HAB\Solr\Response\Json\RecordCollection;
+use HAB\Solr\Response\Json\RecordCollectionConsumerInterface;
+use HAB\Solr\ParameterProviderInterface;
+
+use Symfony\Component\HttpFoundation\ParameterBag;
+
+use Countable;
+use ArrayIterator;
+use IteratorAggregate;
+
+/**
+ * A FacetCollection aggregates FacetAdapter objects.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class FacetCollection implements Countable, IteratorAggregate, ParameterProviderInterface, RecordCollectionConsumerInterface
+{
+
+    /**
+     * Aggregated facets.
+     *
+     * @var array
+     */
+    private $facets;
+
+    /**
+     * Constructor.
+     *
+     * @return void
+     */
+    public function __construct ()
+    {
+        $this->facets = array();
+    }
+
+    /**
+     * Add a facet.
+     *
+     * @param  FacetAdapterInterface $facet
+     * @return void
+     */
+    public function addFacet (FacetAdapterInterface $facet)
+    {
+        $name = $facet->getName();
+        $this->facets[$name] = $facet;
+    }
+
+    /**
+     * Return facet by name.
+     *
+     * @return FacetDecorator|null
+     */
+    public function getFacet ($name)
+    {
+        return isset($this->facets[$name]) ? $this->facets[$name] : null;
+    }
+
+    /**
+     * Return true if collection aggregates facet with name.
+     *
+     * @param  string $name
+     * @return boolean
+     */
+    public function hasFacet ($name)
+    {
+        return isset($this->facets[$name]);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getIterator ()
+    {
+        return new ArrayIterator($this->facets);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setComponentState (ParameterBag $state)
+    {
+        foreach ($this->facets as $facet) {
+            $facet->setComponentState($state);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getComponentState ()
+    {
+        $params = array();
+        foreach ($this->facets as $facet) {
+            $params = array_merge_recursive($params, $facet->getComponentState());
+        }
+        return $params;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSearchParameters ()
+    {
+        $params = array();
+        foreach ($this->facets as $facet) {
+            $params = array_merge_recursive($params, $facet->getSearchParameters());
+        }
+        return $params;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setRecordCollection (RecordCollection $response)
+    {
+        foreach ($this->facets as $name => $facet) {
+            $facet->setRecordCollection($response);
+        }
+    }
+
+    /**
+     * Return number of aggregated facets.
+     *
+     * @return integer
+     */
+    public function count ()
+    {
+        return count($this->facets);
+    }
+
+    /**
+     * Return aggregated facet count.
+     *
+     * @return integer
+     */
+    public function getAggregatedCount ()
+    {
+        $sum = 0;
+        foreach ($this->facets as $facet) {
+            $sum += $facet->getFacetValueContainer()->getAggregatedCount();
+        }
+        return $sum;
+    }
+}

src/HAB/Solr/Facet/FacetImplInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet;
+
+/**
+ * Interface of a backend-specific facet implementations.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface FacetImplInterface
+{
+    /**
+     * Return facet counts.
+     *
+     * Returns an array with {@see Value\FacetValue} objects.
+     *
+     * @return Value\FacetValue[]
+     */
+    public function getFacetCounts ();
+
+    /**
+     * Set selected facet values.
+     *
+     * @param  string[] $selected
+     */
+    public function setSelected (array $selected);
+
+    /**
+     * Return array of selected facet values.
+     *
+     * @return array
+     */
+    public function getSelected ();
+
+    /**
+     * __clone
+     *
+     * @return void
+     */
+    public function __clone ();
+}
\ No newline at end of file

src/HAB/Solr/Facet/Impl/FieldFacet.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\Impl;
+
+use HAB\Solr\Facet\FacetImplInterface;
+use HAB\Solr\Facet\Value\FacetValue;
+
+use HAB\Solr\Response\Json\RecordCollection;
+
+use InvalidArgumentException;
+
+/**
+ * A simple SOLR field facet.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class FieldFacet implements FacetImplInterface
+{
+    /**
+     * Field to facet on.
+     *
+     * @var string
+     */
+    private $field;
+
+    /**
+     * Selected values.
+     *
+     * @var string[]
+     */
+    private $selected;
+
+    /**
+     * Filter query operator.
+     *
+     * @var string
+     */
+    private $fqOperator;
+
+    /**
+     * Filter query tag, if any.
+     *
+     * @var string
+     */
+    private $fqTag;
+
+    /**
+     * Is multiselect enabled?
+     *
+     * @var boolean
+     */
+    private $multiselect;
+
+    /**
+     * Facet options.
+     *
+     * @var string[]
+     */
+    private $options;
+
+    /**
+     * Local parameters.
+     *
+     * @var LocalParams
+     */
+    private $localParams;
+
+    /**
+     * Facet counts.
+     *
+     * @var array
+     */
+    private $counts;
+
+    /**
+     * Constructor.
+     *
+     * @param  string $field
+     * @param  array  $options
+     * @return void
+     */
+    public function __construct ($field, array $options = array())
+    {
+        if (empty($field)) {
+            throw new InvalidArgumentException('Facet field must not be empty');
+        }
+        $this->selected = array();
+        $this->field    = $field;
+        $this->setFacetOptions($options);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSearchParameters ()
+    {
+        $params = $this->getFacetOptions();
+        $params['facet'] = 'true';
+        $params['facet.field'] = sprintf("%s%s", (string)$this->getLocalParams(), $this->field);
+        if ($fq = $this->getFilterQuery()) {
+            $params['fq'] = $fq;
+        }
+        return $params;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setRecordCollection (RecordCollection $response)
+    {
+        $facets = $response->getFacets();
+        $fields = $facets->getFieldFacets();
+        if (isset($fields[$this->field])) {
+            $this->setFacetCounts($fields[$this->field]);
+        }
+    }
+
+    /**
+     * Set facet counts.
+     *
+     * The parameter is expected to be an array or Traversable that
+     * maps index values to value counts.
+     *
+     * @param  array|Traversable $counts
+     * @return void
+     */
+    public function setFacetCounts ($counts)
+    {
+        $this->counts = array();
+        foreach ($counts as $value => $count) {
+            $this->counts []= new FacetValue($value, $count, $this->isSelected($value));
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getFacetCounts ()
+    {
+        if ($this->counts === null) {
+            $this->setFacetCounts(array());
+        }
+        return $this->counts;
+    }
+
+    /**
+     * Return local params.
+     *
+     * @return LocalParams
+     */
+    public function getLocalParams ()
+    {
+        if (empty($this->localParams)) {
+            $this->localParams = new LocalParams();
+        }
+        return $this->localParams;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setSelected (array $selected)
+    {
+        $this->selected = $selected;
+    }
+
+    /**
+     * Return selected values.
+     *
+     * @return string[]
+     */
+    public function getSelected ()
+    {
+        if ($this->selected === null) {
+            $this->setSelected(array());
+        }
+        return $this->selected;
+    }
+
+    /**
+     * Is the value selected?
+     *
+     * @param  string $value
+     * @return boolean
+     */
+    public function isSelected ($value)
+    {
+        return in_array($value, $this->selected);
+    }
+
+    /**
+     * Set boolean operator for filter query.
+     *
+     * @throws InvalidArgumentException Boolean operator neither 'or' nor 'and'
+     *
+     * @param  string $operator
+     * @return void
+     */
+    public function setFilterQueryOperator ($operator)
+    {
+        $operator = trim(strtoupper($operator));
+        if ($operator !== 'AND' && $operator !== 'OR') {
+            throw new InvalidArgumentException(
+                sprintf(
+                    "Invalid filter query operator -- expected 'OR' or 'AND', got %s', $operator",
+                    $operator
+                )
+            );
+        }
+        $this->fqOperator = $operator;
+    }
+
+    /**
+     * Return filter query operator.
+     *
+     * @return string
+     */
+    public function getFilterQueryOperator ()
+    {
+        if (empty($this->fqOperator)) {
+            $this->setFilterQueryOperator('AND');
+        }
+        return $this->fqOperator;
+    }
+
+    /**
+     * Return filter query tag.
+     *
+     * @return string
+     */
+    public function getFilterQueryTag ()
+    {
+        if (empty($this->fqTag)) {
+            $this->fqTag = sprintf('%s.%s', $this->field, spl_object_hash($this));
+        }
+        return $this->fqTag;
+    }
+
+    /**
+     * Is multiselected enabled?
+     *
+     * @return boolean
+     */
+    public function isMultiselect ()
+    {
+        return $this->multiselect;
+    }
+
+    /**
+     * Enable or disable multiselect.
+     *
+     * When multiselect is enabled that facet's filter query is
+     * excluded from calculating the facet counts.
+     *
+     * @param  boolean $enable
+     * @return void
+     */
+    public function enableMultiselect ($enable = true)
+    {
+        $local = $this->getLocalParams();
+        if ($enable) {
+            $local->set('ex', $this->getFilterQueryTag());
+        } else {
+            $local->remove('ex');
+        }
+        $this->multiselect = (boolean)$enable;
+    }
+
+    /**
+     * Return the filter query.
+     *
+     * @return string
+     */
+    public function getFilterQuery ()
+    {
+        if (!empty($this->selected)) {
+            $local = new LocalParams();
+            $local->add('q.op', $this->getFilterQueryOperator());
+            if ($this->isMultiselect()) {
+                $local->add('tag', $this->getFilterQueryTag());
+            }
+            return sprintf('%s%s:(%s)', (string)$local, $this->field, implode(' ', array_map(array($this, 'escape'), $this->selected)));
+        }
+    }
+
+    /**
+     * Set facet options.
+     *
+     * Facet options are encoded using SOLR's field specific syntax
+     * option, e.g. as f.FIELD.option.
+     *
+     * @param  string[] $options
+     * @return void
+     */
+    public function setFacetOptions (array $options)
+    {
+        $this->options = array();
+        $field = $this->field;
+        foreach ($options as $key => $value) {
+            $this->options["f.{$field}.{$key}"] = $value;
+        }
+    }
+
+    /**
+     * Return facet options.
+     *
+     * @return array
+     */
+    public function getFacetOptions ()
+    {
+        if ($this->options === null) {
+            $this->setFacetOptions(array());
+        }
+        return $this->options;
+    }
+
+    /**
+     * Escape values for filter query request.
+     *
+     * Encloses each value in double-quotes.
+     *
+     * @param  string $value
+     * @return string
+     */
+    private function escape ($value)
+    {
+        return '"' . addcslashes($value, '"') . '"';
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function __clone ()
+    {
+        if ($this->localParams) {
+            $this->localParams = clone($this->localParams);
+        }
+        $this->fqTag = null;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/Impl/LocalParams.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\Impl;
+
+use HAB\Solr\ParamBag;
+
+/**
+ * Representing SOLR local params.
+ *
+ * @see https://wiki.apache.org/solr/LocalParams
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class LocalParams extends ParamBag
+{
+    /**
+     * Return local param string.
+     *
+     * @return string
+     */
+    public function __toString ()
+    {
+        if (!empty($this->params)) {
+            $params = array();
+            foreach ($this->params as $key => $values) {
+                foreach ($values as $value) {
+                    if (strpos($value, ' ') !== false) {
+                        $value = '"' . addcslashes($value, '"') . '"';
+                    }
+                    $params []= "{$key}={$value}";
+                }
+            }
+            return sprintf('{!%s}', implode(' ', $params));
+        }
+        return '';
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/LabelFactory/DefaultLabelFactory.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\LabelFactory;
+
+/**
+ * The default implementation simply returns the value.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class DefaultLabelFactory implements LabelFactoryInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function createLabel ($value)
+    {
+        return $value;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/LabelFactory/LabelFactoryInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\LabelFactory;
+
+/**
+ * A LabelFactory creates a label for a facet value.
+ *
+ * The function self::createLabel() is called with the actual value
+ * rather then a FacetValue to enable usage of the LabelFactory in
+ * cirumstances where no call to the backend is required.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface LabelFactoryInterface
+{
+    /**
+     * Return label for value.
+     *
+     * @param  string $value
+     * @return string
+     */
+    public function createLabel ($value);
+}
\ No newline at end of file

src/HAB/Solr/Facet/LabelFactory/MapLabelFactory.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\LabelFactory;
+
+/**
+ * Uses a map of values to labels.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class MapLabelFactory implements LabelFactoryInterface
+{
+    /**
+     * Translation map.
+     *
+     * @var array
+     */
+    private $map;
+
+    /**
+     * Constructor.
+     *
+     * @param  array $map
+     * @return void
+     */
+    public function __construct (array $map)
+    {
+        $this->map = $map;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function createLabel ($value)
+    {
+        if ($value && isset($this->map[$value])) {
+            return $this->map[$value];
+        }
+        return $value;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/LabelFactory/RegExpLabelFactory.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\LabelFactory;
+
+/**
+ * Obtain a label by performing a search/replace operation on the value.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2013-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class RegExpLabelFactory implements LabelFactoryInterface
+{
+    /**
+     * Pattern.
+     *
+     * @var string
+     */
+    private $pattern;
+
+    /**
+     * Replace template.
+     *
+     * @var string
+     */
+    private $template;
+
+    /**
+     * Constructor.
+     *
+     * @param  string $pattern
+     * @param  string $template
+     * @return void
+     */
+    public function __construct ($pattern, $template)
+    {
+        $this->pattern  = $pattern;
+        $this->template = $template;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function createLabel ($value)
+    {
+        if (preg_match($this->pattern, $value)) {
+            return preg_replace($this->pattern, $this->template, $value);
+        }
+        return $value;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Facet/Value/Container/ContainerInterface.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\Value\Container;
+
+use HAB\Solr\Facet\Value\FacetValue;
+
+use Countable;
+use Iterator;
+
+/**
+ * Interface of a facet value container.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+interface ContainerInterface extends Countable
+{
+    /**
+     * Return iterator to iterate over contained facet values.
+     *
+     * @return Iterator
+     */
+    public function getIterator ();
+
+    /**
+     * Return iterator to iterate over selected facet values only.
+     *
+     * @return Iterator
+     */
+    public function getSelectedValueIterator ();
+
+    /**
+     * Are there selected values?
+     *
+     * @return boolean
+     */
+    public function hasSelectedValue ();
+    
+    /**
+     * Add facet value.
+     *
+     * @param  FacetValue $value
+     * @return void
+     */
+    public function addFacetValue (FacetValue $value);
+
+    /**
+     * Sort facet values by facet value label.
+     *
+     * @param  boolean $reverse Sort in reverse order
+     * @return void
+     */
+    public function sortByLabel ($reverse = false);
+
+    /**
+     * Sort facet values by facet value count.
+     *
+     * @param  boolean $reverse Sort in reverse order
+     * @return void
+     */
+    public function sortByCount ($reverse = false);
+}
\ No newline at end of file

src/HAB/Solr/Facet/Value/Container/FacetValueList.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Facet\Value\Container;
+
+use HAB\Solr\Facet\Value\FacetValue;
+
+use ArrayIterator;
+use IteratorIterator;
+
+/**
+ * A flat list of facet values.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright Copyright (c) 2014-2016 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class FacetValueList implements ContainerInterface
+{
+    /**
+     * Facet values.
+     *
+     * @var array
+     */
+    private $values;
+
+    /**
+     * Does the list contain a selected value?
+     *
+     * @var boolean
+     */
+    private $hasSelectedValue = false;
+
+    /**
+     * Constructor.
+     *
+     * @return void
+     */
+    public function __construct ()
+    {
+        $this->values = array();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getIterator ()
+    {
+        return new IteratorIterator(new ArrayIterator($this->values));
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getSelectedValueIterator ()
+    {
+        return new SelectedFacetValueFilterIterator($this->getIterator());
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function hasSelectedValue ()
+    {
+        return $this->hasSelectedValue;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function addFacetValue (FacetValue $value)
+    {
+        if ($value->isSelected()) {
+            $this->hasSelectedValue = true;
+        }
+        if (!in_array($value, $this->values, true)) {
+            $this->values []= $value;
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function sortByLabel ($reverse = false)
+    {
+        usort($this->values, array('HAB Solr\Search\Facet\Value\FacetValue', 'compareByLabel'));
+        if ($reverse) {
+            $this->values = array_reverse($this->values);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function sortByCount ($reverse = false)
+    {
+        usort($this->values, array('HAB Solr\Search\Facet\Value\FacetValue', 'compareByCount'));
+        if ($reverse) {
+            $this->values = array_reverse($this->values);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function count ()
+    {
+        return count($this->values);
+    }
+}
\ No newline at end of file