diff --git a/search_api_solr_datasource.module b/search_api_solr_datasource.module
index 252b5ac..bf0c481 100644
--- a/search_api_solr_datasource.module
+++ b/search_api_solr_datasource.module
@@ -8,20 +8,10 @@
 use Drupal\search_api\IndexInterface;
 use Drupal\search_api\Query\QueryInterface;
 use Drupal\search_api\Query\ResultSetInterface;
+use Drupal\search_api_solr\Plugin\search_api\backend\SearchApiSolrBackend;
 use Solarium\QueryType\Select\Query\Query as SolariumQuery;
 use Solarium\QueryType\Select\Result\Result as SolariumResult;
 
-/**
- * Implements hook_search_api_field_type_mapping_alter().
- *
- * Add mappings for Solr data types to Search API data types.
- */
-function search_api_solr_datasource_search_api_field_type_mapping_alter(array &$mapping) {
-  $mapping['long'] = 'integer';
-  $mapping['tdate'] = 'date';
-  $mapping['text'] = 'text';
-}
-
 /**
  * Implements hook_search_api_solr_field_mapping_alter().
  *
@@ -55,7 +45,9 @@ function search_api_solr_datasource_search_api_solr_field_mapping_alter(IndexInt
   // Re-map the indexed fields.
   foreach ($fields as $raw => $name) {
     // Ignore the Search API fields.
-    if (strpos($raw, 'search_api_') === 0) {
+    if (strpos($raw, 'search_api_') === 0
+        || empty($index_fields[$raw])
+        || $index_fields[$raw]->getDatasourceId() !== 'solr_document') {
       continue;
     }
     $fields[$raw] = $index_fields[$raw]->getPropertyPath();
@@ -68,8 +60,8 @@ function search_api_solr_datasource_search_api_solr_field_mapping_alter(IndexInt
 function search_api_solr_datasource_search_api_solr_query_alter(SolariumQuery $solarium_query, QueryInterface $query) {
   // Do not alter the query if the index does not use the solr_document
   // datasource.
-  $datasources = $query->getIndex()->getDatasources();
-  if (!isset($datasources['solr_document'])) {
+  $index = $query->getIndex();
+  if (!$index->isValidDatasource('solr_document')) {
     return;
   }
 
@@ -78,9 +70,38 @@ function search_api_solr_datasource_search_api_solr_query_alter(SolariumQuery $s
   $solarium_query->removeFilterQuery('index_id');
 
   // Set requestHandler for the query type.
-  $config = $query->getIndex()->getDatasource('solr_document')->getConfiguration();
-  if (!empty($config['advanced']['request_handler'])) {
-    $solarium_query->addParam('qt', $config['advanced']['request_handler']);
+  $config = $index->getDatasource('solr_document')->getConfiguration();
+  if (!empty($config['request_handler'])) {
+    $solarium_query->addParam('qt', $config['request_handler']);
+  }
+
+  // Set the default query, if necessary and configured.
+  if (!$solarium_query->getQuery() && !empty($config['default_query'])) {
+    $solarium_query->setQuery($config['default_query']);
+  }
+
+  $backend = $index->getServerInstance()->getBackend();
+  if ($backend instanceof SearchApiSolrBackend) {
+    $solr_config = $backend->getConfiguration();
+    // @todo Should we maybe not even check that setting and use this to
+    //   auto-enable fields retrieval from Solr?
+    if (!empty($solr_config['retrieve_data'])) {
+      $fields_list = [];
+      foreach ($backend->getSolrFieldNames($index) as $solr_field_name) {
+        $fields_list[] = $solr_field_name;
+      }
+      $extra_fields = [
+        'language_field',
+        'label_field',
+        'url_field',
+      ];
+      foreach ($extra_fields as $config_key) {
+        if (!empty($config[$config_key])) {
+          $fields_list[] = $config[$config_key];
+        }
+      }
+      $solarium_query->setFields(array_unique($fields_list));
+    }
   }
 }
 
diff --git a/src/Plugin/DataType/SolrDocument.php b/src/Plugin/DataType/SolrDocument.php
index efa34f6..6a2dbca 100644
--- a/src/Plugin/DataType/SolrDocument.php
+++ b/src/Plugin/DataType/SolrDocument.php
@@ -3,9 +3,11 @@
 namespace Drupal\search_api_solr_datasource\Plugin\DataType;
 
 use Drupal\Core\TypedData\ComplexDataInterface;
+use Drupal\Core\TypedData\Exception\MissingDataException;
 use Drupal\Core\TypedData\TypedData;
 use Drupal\search_api\Item\ItemInterface;
 use Drupal\search_api_solr_datasource\TypedData\SolrDocumentDefinition;
+use Solarium\QueryType\Select\Result\AbstractDocument;
 
 /**
  * Defines the "Solr document" data type.
@@ -66,14 +68,42 @@ public function get($property_name) {
     if (!isset($this->item)) {
       throw new MissingDataException("Unable to get Solr field $property_name as no item has been provided.");
     }
-    $field = $this->item->getField($property_name);
-    if ($field === NULL) {
-      throw new \InvalidArgumentException("The Solr field $property_name has not been configured in the index.");
-    }
-    // Create a new typed data object from the item's field data.
+
+    // First, verify that this field actually exists in the Solr server. If we
+    // can't get a definition for it, it doesn't exist.
     /** @var \Drupal\search_api_solr_datasource\Plugin\DataType\SolrField $plugin */
     $plugin = \Drupal::typedDataManager()->getDefinition('solr_field')['class'];
-    return $plugin::createFromField($field, $property_name, $this);
+    $field_manager = \Drupal::getContainer()->get('solr_field.manager');
+    $server_id = $this->item->getIndex()->getServerInstance()->id();
+    $fields = $field_manager->getFieldDefinitions($server_id);
+    if (empty($fields[$property_name])) {
+      throw new \InvalidArgumentException("The Solr field $property_name could not be found on the $server_id server.");
+    }
+    // Create a new typed data object from the item's field data.
+    $property = $plugin::createInstance($fields[$property_name], $property_name, $this);
+
+    // Now that we have the property, try to find its values. We first look at
+    // the field values contained in the result item.
+    $found = FALSE;
+    foreach ($this->item->getFields(FALSE) as $field) {
+      if ($field->getDatasourceId() === 'solr_document'
+          && $field->getPropertyPath() === $property_name) {
+        $property->setValue($field->getValues());
+        $found = TRUE;
+        break;
+      }
+    }
+
+    if (!$found) {
+      // If that didn't work, maybe we can get the field from the Solr document?
+      $document = $this->item->getExtraData('search_api_solr_document');
+      if ($document instanceof AbstractDocument
+          && isset($document[$property_name])) {
+        $property->setValue($document[$property_name]);
+      }
+    }
+
+    return $property;
   }
 
   /**
diff --git a/src/Plugin/DataType/SolrField.php b/src/Plugin/DataType/SolrField.php
index aa68ef5..7f49ff3 100644
--- a/src/Plugin/DataType/SolrField.php
+++ b/src/Plugin/DataType/SolrField.php
@@ -22,11 +22,11 @@
 class SolrField extends TypedData implements \IteratorAggregate, TypedDataInterface {
 
   /**
-   * The wrapped Search API Field.
+   * The field value(s).
    *
-   * @var \Drupal\search_api\Item\FieldInterface|null
+   * @var mixed
    */
-  protected $field;
+  protected $value;
 
   /**
    * Creates an instance wrapping the given Field.
@@ -45,36 +45,18 @@ public static function createFromField(FieldInterface $field, $name, TypedDataIn
     /** @var \Drupal\search_api_solr_datasource\SolrFieldManagerInterface $field_manager */
     $field_manager = \Drupal::getContainer()->get('solr_field.manager');
     $server_id = $field->getIndex()->getServerInstance()->id();
-    $field_id = $field->getFieldIdentifier();
+    $field_id = $field->getPropertyPath();
     $definition = $field_manager->getFieldDefinitions($server_id)[$field_id];
     $instance = new static($definition, $name, $parent);
-    $instance->setValue($field);
+    $instance->setValue($field->getValues());
     return $instance;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function getValue() {
-    return $this->field;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function setValue($field, $notify = TRUE) {
-    $this->field = $field;
-    // Notify the parent of any changes.
-    if ($notify && isset($this->parent)) {
-      $this->parent->onChange($this->name);
-    }
-  }
-
   /**
    * {@inheritdoc}
    */
   public function getIterator() {
-    return isset($this->field) ? $this->field->getIterator() : new \ArrayIterator([]);
+    return new \ArrayIterator((array) $this->value);
   }
 
 }
diff --git a/src/Plugin/search_api/datasource/SolrDocument.php b/src/Plugin/search_api/datasource/SolrDocument.php
index 3b476a7..5e6f2bf 100644
--- a/src/Plugin/search_api/datasource/SolrDocument.php
+++ b/src/Plugin/search_api/datasource/SolrDocument.php
@@ -7,6 +7,7 @@
 use Drupal\Core\TypedData\ComplexDataInterface;
 use Drupal\search_api\Datasource\DatasourcePluginBase;
 use Drupal\search_api\Plugin\PluginFormTrait;
+use Drupal\search_api\SearchApiException;
 use Drupal\search_api_solr_datasource\SolrDocumentFactoryInterface;
 use Drupal\search_api_solr_datasource\SolrFieldManagerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -17,7 +18,7 @@
  * @SearchApiDatasource(
  *   id = "solr_document",
  *   label = @Translation("Solr Document"),
- *   description = @Translation("Exposes external Solr Documents as a datasource."),
+ *   description = @Translation("Search through external Solr content. (Only works if this index is attached to a Solr-based server.)"),
  * )
  */
 class SolrDocument extends DatasourcePluginBase implements PluginFormInterface {
@@ -101,15 +102,65 @@ public function getSolrFieldManager() {
    * {@inheritdoc}
    */
   public function getItemId(ComplexDataInterface $item) {
-    // @todo Implement this.
+    return $this->getFieldValue($item, 'id_field');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getItemLabel(ComplexDataInterface $item) {
+    return $this->getFieldValue($item, 'label_field');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getItemLanguage(ComplexDataInterface $item) {
+    if ($this->configuration['language_field']) {
+      return $this->getFieldValue($item, 'language_field');
+    }
+    return parent::getItemLanguage($item);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getItemUrl(ComplexDataInterface $item) {
+    return $this->getFieldValue($item, 'url_field');
+  }
+
+  /**
+   * Retrieves a scalar field value from a result item.
+   *
+   * @param \Drupal\Core\TypedData\ComplexDataInterface $item
+   *   The result item.
+   * @param string $config_key
+   *   The key in the configuration.
+   *
+   * @return mixed|null
+   *   The scalar value of the specified field (first value for multi-valued
+   *   fields), if it exists; NULL otherwise.
+   */
+  protected function getFieldValue(ComplexDataInterface $item, $config_key) {
+    if (empty($this->configuration[$config_key])) {
+      return NULL;
+    }
+    $values = $item->get($this->configuration[$config_key])->getValue();
+    if (is_array($values)) {
+      $values = $values ? reset($values) : NULL;
+    }
+    return $values ?: NULL;
   }
 
   /**
    * {@inheritdoc}
    */
   public function getPropertyDefinitions() {
-    // @todo Handle IndexInterface::getServerInstance() returning NULL.
-    $fields = $this->getSolrFieldManager()->getFieldDefinitions($this->index->getServerInstance()->id());
+    $fields = [];
+    $server_id = $this->index->getServerId();
+    if ($server_id) {
+      $fields = $this->getSolrFieldManager()->getFieldDefinitions($server_id);
+    }
     return $fields;
   }
 
@@ -117,16 +168,19 @@ public function getPropertyDefinitions() {
    * {@inheritdoc}
    */
   public function loadMultiple(array $ids) {
-    // Query the index for the Solr documents.
-    $query = $this->index->query(['limit' => 1]);
-    foreach ($ids as $id) {
-      $query->addCondition('search_api_id', $id);
-    }
-    $query->execute();
-    $results = $query->getResults()->getResultItems();
     $documents = [];
-    foreach ($results as $id => $result) {
-      $documents[$id] = $this->solrDocumentFactory->create($result);
+    try {
+      // Query the index for the Solr documents.
+      $results = $this->index->query()
+        ->addCondition('search_api_id', $ids, 'IN')
+        ->execute()
+        ->getResultItems();
+      foreach ($results as $id => $result) {
+        $documents[$id] = $this->solrDocumentFactory->create($result);
+      }
+    }
+    catch (SearchApiException $e) {
+      // Couldn't load items from server, return an empty array.
     }
     return $documents;
   }
@@ -137,8 +191,11 @@ public function loadMultiple(array $ids) {
   public function defaultConfiguration() {
     $config = [];
     $config['id_field'] = '';
-    $config['advanced']['request_handler'] = '';
-    $config['advanced']['default_query'] = '*:*';
+    $config['request_handler'] = '';
+    $config['label_field'] = '';
+    $config['language_field'] = '';
+    $config['url_field'] = '';
+    $config['default_query'] = '*:*';
     return $config;
   }
 
@@ -146,13 +203,30 @@ public function defaultConfiguration() {
    * {@inheritdoc}
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+    // Get the available fields from the server (if a server has already been
+    // set).
+    $fields = $single_valued_fields = [];
+    foreach ($this->getPropertyDefinitions() as $name => $property) {
+      $fields[$name] = $property->getLabel();
+      if (!$property->isMultivalued()) {
+        $single_valued_fields[$name] = $property->getLabel();
+      }
+    }
+
     $form['id_field'] = [
       '#type' => 'textfield',
       '#title' => $this->t('ID field'),
       '#required' => TRUE,
-      '#description' => $this->t('Enter the name of a field from your Solr schema that contains unique ID values.'),
+      '#description' => $this->t('Enter the name of the field from your Solr schema that contains unique ID values.'),
       '#default_value' => $this->configuration['id_field'],
     ];
+    // If there is already a valid server, we can transform the text field into
+    // a select box.
+    if ($single_valued_fields) {
+      $form['id_field']['#type'] = 'select';
+      $form['id_field']['#options'] = $single_valued_fields;
+      $form['id_field']['#description'] = $this->t('Select the Solr index field that contains unique ID values.');
+    }
     $form['advanced'] = [
       '#type' => 'details',
       '#title' => $this->t('Advanced configuration'),
@@ -162,18 +236,63 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
       '#type' => 'textfield',
       '#title' => $this->t('Request handler'),
       '#description' => $this->t("Enter the name of a requestHandler from the core's solrconfig.xml file.  This should only be necessary if you need to specify a handler to use other than the default."),
-      '#default_value' => $this->configuration['advanced']['request_handler'],
+      '#default_value' => $this->configuration['request_handler'],
     ];
-    // @todo Figure out if we actually need this setting.  It was copied over
-    //   from Sarnia, but it seems like in D8 Search API Solr defaults to
-    //   selecting all records.  It may not be necessary.
-    /*$form['advanced']['default_query'] = [
+    $form['advanced']['default_query'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Default query'),
-      '#description' => $this->t("Enter a default query parameter. This may only be necessary if a default query cannot be specified in the solrconfig.xml."),
-      '#default_value' => $this->configuration['advanced']['default_query'],
-    ];*/
+      '#description' => $this->t("Enter a default query parameter. This is only necessary if a default query cannot be specified in the solrconfig.xml file."),
+      '#default_value' => $this->configuration['default_query'],
+    ];
+    $form['advanced']['label_field'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Label field'),
+      '#description' => $this->t('Enter the name of the field from your Solr schema that should be considered the label (if any).'),
+      '#default_value' => $this->configuration['label_field'],
+    ];
+    $form['advanced']['language_field'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Language field'),
+      '#description' => $this->t('Enter the name of the field from your Solr schema that should be considered the label (if any).'),
+      '#default_value' => $this->configuration['language_field'],
+    ];
+    $form['advanced']['url_field'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('URL field'),
+      '#description' => $this->t('Enter the name of the field from your Solr schema that should be considered the label (if any).'),
+      '#default_value' => $this->configuration['url_field'],
+    ];
+    // If there is already a valid server, we can transform the text fields into
+    // select boxes.
+    if ($fields) {
+      $fields = [
+        '' => $this->t('None'),
+      ] + $fields;
+      $form['advanced']['label_field']['#type'] = 'select';
+      $form['advanced']['label_field']['#options'] = $fields;
+      $form['advanced']['label_field']['#description'] = $this->t('Select the Solr index field that should be considered the label (if any).');
+      $form['advanced']['language_field']['#type'] = 'select';
+      $form['advanced']['language_field']['#options'] = $fields;
+      $form['advanced']['language_field']['#description'] = $this->t("Select the Solr index field that contains the document's language code (if any).");
+      $form['advanced']['url_field']['#type'] = 'select';
+      $form['advanced']['url_field']['#options'] = $fields;
+      $form['advanced']['url_field']['#description'] = $this->t("Select the Solr index field that contains the document's URL (if any).");
+    }
+
     return $form;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
+    // We want the form fields displayed inside an "Advanced configuration"
+    // fieldset, but we don't want them to be actually stored inside a nested
+    // "advanced" key. (This could also be done via "#parents", but that's
+    // pretty tricky to get right in a subform.)
+    $values = &$form_state->getValues();
+    $values += $values['advanced'];
+    unset($values['advanced']);
+  }
+
 }
diff --git a/src/SolrFieldManager.php b/src/SolrFieldManager.php
index 887a795..1a42c0d 100644
--- a/src/SolrFieldManager.php
+++ b/src/SolrFieldManager.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\search_api_solr_datasource;
 
+use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Cache\UseCacheBackendTrait;
@@ -59,7 +60,7 @@ public function getFieldDefinitions($server_id) {
    * Builds the field definitions for a Solr server from its Luke handler.
    *
    * @param string $server_id
-   *   The server from which we are retreiving field information.
+   *   The server from which we are retrieving field information.
    *
    * @return \Drupal\search_api_solr_datasource\TypedData\SolrFieldDefinitionInterface[]
    *   The array of field definitions for the server, keyed by field name.
@@ -72,16 +73,44 @@ protected function buildFieldDefinitions($server_id) {
     if ($server === NULL) {
       throw new \InvalidArgumentException('The Search API server could not be loaded.');
     }
-    if (!$server->getBackend() instanceof SolrBackendInterface) {
+    $backend = $server->getBackend();
+    if (!$backend instanceof SolrBackendInterface) {
       throw new \InvalidArgumentException("The Search API server's backend must be an instance of SolrBackendInterface.");
     }
     $fields = [];
     try {
-      $luke = $server->getBackend()->getSolrConnector()->getLuke();
-      foreach ($luke['fields'] as $label => $definition) {
+      $luke = $backend->getSolrConnector()->getLuke();
+      foreach ($luke['fields'] as $name => $definition) {
         $field = new SolrFieldDefinition($definition);
+        $label = Unicode::ucfirst(trim(str_replace('_', ' ', $name)));
         $field->setLabel($label);
-        $fields[$label] = $field;
+        // The Search API can't deal with arbitrary item types. To make things
+        // easier, just use one of those known to the Search API.
+        if (strpos($field->getDataType(), 'text') !== FALSE) {
+          $field->setDataType('search_api_text');
+        }
+        elseif (strpos($field->getDataType(), 'date') !== FALSE) {
+          $field->setDataType('timestamp');
+        }
+        elseif (strpos($field->getDataType(), 'int') !== FALSE) {
+          $field->setDataType('integer');
+        }
+        elseif (strpos($field->getDataType(), 'long') !== FALSE) {
+          $field->setDataType('integer');
+        }
+        elseif (strpos($field->getDataType(), 'float') !== FALSE) {
+          $field->setDataType('float');
+        }
+        elseif (strpos($field->getDataType(), 'double') !== FALSE) {
+          $field->setDataType('float');
+        }
+        elseif (strpos($field->getDataType(), 'bool') !== FALSE) {
+          $field->setDataType('boolean');
+        }
+        else {
+          $field->setDataType('string');
+        }
+        $fields[$name] = $field;
       }
     }
     catch (SearchApiSolrException $e) {