diff --git a/src/FieldHandler/FieldHandlerBase.php b/src/FieldHandler/FieldHandlerBase.php
index 38249c5..6680771 100644
--- a/src/FieldHandler/FieldHandlerBase.php
+++ b/src/FieldHandler/FieldHandlerBase.php
@@ -3,6 +3,7 @@
 namespace Drupal\commerce_sheets\FieldHandler;
 
 use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\PluginBase;
 
@@ -12,7 +13,8 @@ use PhpOffice\PhpSpreadsheet\Style\Style;
 /**
  * Base class for all field handler plugins.
  */
-abstract class FieldHandlerBase extends PluginBase implements FieldHandlerInterface {
+abstract class FieldHandlerBase extends PluginBase implements
+  FieldHandlerInterface {
 
   /**
    * {@inheritdoc}
@@ -88,8 +90,35 @@ abstract class FieldHandlerBase extends PluginBase implements FieldHandlerInterf
   /**
    * {@inheritdoc}
    */
-  public function toCellValue($field) {
-    return $field->value;
+  public function validate($value) {}
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellGetValue($cell) {
+    return (string) $cell->getValue();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellToField($cell, FieldItemListInterface $field) {
+    if ($this->getLocked()) {
+      return;
+    }
+
+    $field->setValue($this->fromCellGetValue($cell));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function toCellValue($property_value) {
+    if ($property_value instanceof FieldItemListInterface) {
+      return $property_value->value;
+    }
+
+    return $property_value;
   }
 
   /**
@@ -107,4 +136,14 @@ abstract class FieldHandlerBase extends PluginBase implements FieldHandlerInterf
     }
   }
 
+  /**
+   * Returns the `locked` setting for the field handler.
+   *
+   * @return bool
+   *   The value of the `locked` setting.
+   */
+  protected function getLocked() {
+    return $this->getConfiguration()['locked'];
+  }
+
 }
diff --git a/src/FieldHandler/FieldHandlerInterface.php b/src/FieldHandler/FieldHandlerInterface.php
index 528997d..ec28830 100644
--- a/src/FieldHandler/FieldHandlerInterface.php
+++ b/src/FieldHandler/FieldHandlerInterface.php
@@ -8,6 +8,7 @@ use Drupal\Component\Plugin\PluginInspectionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
 
+use PhpOffice\PhpSpreadsheet\Cell\Cell;
 use PhpOffice\PhpSpreadsheet\Style\Style;
 
 /**
@@ -19,6 +20,8 @@ use PhpOffice\PhpSpreadsheet\Style\Style;
  *   storing in fields.
  * - Convert field values into cell values for storing in the exported
  *   spreadsheet.
+ *
+ * @I Rename to PropertyHandler
  */
 interface FieldHandlerInterface extends
   ConfigurableInterface,
@@ -26,8 +29,38 @@ interface FieldHandlerInterface extends
   PluginFormInterface,
   PluginInspectionInterface {
 
+  /**
+   * Validates that the given value is in the format expected by the field.
+   *
+   * @param mixed $value
+   *   The value to validate.
+   */
   public function validate($value);
 
+  /**
+   * Returns the value of the given cell.
+   *
+   * The value is returned in the most reasonable format for the data contained
+   * in the cell.
+   *
+   * @param \PhpOffice\PhpSpreadsheet\Cell\Cell $cell
+   *   The cell to get the value from.
+   *
+   * @return mixed
+   *   The value.
+   */
+  public function fromCellGetValue(Cell $cell);
+
+  /**
+   * Stores the value of the cell to the given field.
+   *
+   * @param \PhpOffice\PhpSpreadsheet\Cell\Cell $cell
+   *   The cell to get the value from.
+   * @param \Drupal\Core\Field\FieldItemListInterface $field
+   *   The field where to store the value to.
+   */
+  public function fromCellToField(Cell $cell, FieldItemListInterface $field);
+
   /**
    * Returns the cell value for the given field.
    *
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Boolean.php b/src/Plugin/CommerceSheets/FieldHandler/Boolean.php
index 8805eb5..054b2ad 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Boolean.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Boolean.php
@@ -19,6 +19,28 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  */
 class Boolean extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellToField($cell, $field) {
+    if ($this->getLocked()) {
+      return;
+    }
+
+    $value = NULL;
+    switch ($cell->getValue()) {
+      case 'Y':
+        $value = '1';
+        break;
+
+      case 'N':
+        $value = '0';
+        break;
+    }
+
+    $field->setValue($value);
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Bundle.php b/src/Plugin/CommerceSheets/FieldHandler/Bundle.php
index c046514..0d2f127 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Bundle.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Bundle.php
@@ -2,8 +2,6 @@
 
 namespace Drupal\commerce_sheets\Plugin\CommerceSheets\FieldHandler;
 
-use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
-
 /**
  * Provides a handler plugin for bundle fields.
  *
@@ -17,7 +15,7 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  *   }
  * )
  */
-class Bundle extends FieldHandlerBase {
+class Bundle extends EntityReference {
 
   /**
    * {@inheritdoc}
@@ -29,12 +27,4 @@ class Bundle extends FieldHandlerBase {
     ] + parent::defaultConfiguration();
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function toCellValue($field) {
-    $entity = $field->entity;
-    return $entity->label() . ' (' . $entity->id() . ')';
-  }
-
 }
diff --git a/src/Plugin/CommerceSheets/FieldHandler/EntityReference.php b/src/Plugin/CommerceSheets/FieldHandler/EntityReference.php
index 0185397..05ac8bb 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/EntityReference.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/EntityReference.php
@@ -17,6 +17,49 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  */
 class EntityReference extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellGetValue($cell) {
+    $values = $cell->getValue();
+    if (!$values) {
+      return;
+    }
+
+    $ids = array_map(
+      function ($value) {
+        $id = NULL;
+
+        // The value should be in the format "label (entity id)'; match the ID
+        // from inside the parentheses.
+        if (preg_match("/.+\s\(([^\)]+)\)/", $value, $matches)) {
+          $id = $matches[1];
+        }
+
+        return $id;
+      },
+      explode(',', $values)
+    );
+
+    return array_filter($ids);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellToField($cell, $field) {
+    if ($this->getLocked()) {
+      return;
+    }
+
+    $ids = $this->fromCellGetValue($cell);
+    if (!$ids) {
+      $field->setValue(NULL);
+    }
+
+    $field->setValue($ids);
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Integer.php b/src/Plugin/CommerceSheets/FieldHandler/Integer.php
index b3bf625..0c01ae2 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Integer.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Integer.php
@@ -21,6 +21,13 @@ use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
  */
 class Integer extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellGetValue($cell) {
+    return (int) $cell->getValue();
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Measurement.php b/src/Plugin/CommerceSheets/FieldHandler/Measurement.php
index b99d5e3..d64b59c 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Measurement.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Measurement.php
@@ -17,6 +17,22 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  */
 class Measurement extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellGetValue($cell) {
+    $value = $cell->getValue();
+    if (!$value) {
+      return;
+    }
+
+    $value_parts = explode(' ', $value);
+    return [
+      'number' => $value_parts[0],
+      'unit' => $value_parts[1],
+    ];
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Path.php b/src/Plugin/CommerceSheets/FieldHandler/Path.php
index 98342de..4a44dcc 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Path.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Path.php
@@ -17,6 +17,40 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  */
 class Path extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellToField($cell, $field) {
+    if ($this->getLocked()) {
+      return;
+    }
+
+    $is_pathauto = FALSE;
+
+    // Detect if we have a Pathauto field first - and handle accordingly.
+    // If the cell does not have an alias defined, it will get its alias from
+    // the pathauto pattern.
+    $field_definition = $field->getFieldDefinition();
+    $type_definition = \Drupal::service('plugin.manager.field.field_type')
+      ->getDefinition($field_definition->getType());
+    $type_properties = $type_definition['class']::propertyDefinitions(
+      $field_definition->getFieldStorageDefinition()
+    );
+    if (isset($type_properties['pathauto'])) {
+      $is_pathauto = TRUE;
+    }
+
+    $value = $cell->getValue();
+    if (!$value) {
+      $value = NULL;
+    }
+    $field->alias = $value;
+
+    if ($is_pathauto) {
+      $field->pathauto = $value ? 0 : 1;
+    }
+  }
+
   /**
    * {@inheritdoc}
    */
diff --git a/src/Plugin/CommerceSheets/FieldHandler/Price.php b/src/Plugin/CommerceSheets/FieldHandler/Price.php
index c1dfaa9..5f27427 100644
--- a/src/Plugin/CommerceSheets/FieldHandler/Price.php
+++ b/src/Plugin/CommerceSheets/FieldHandler/Price.php
@@ -17,6 +17,22 @@ use Drupal\commerce_sheets\FieldHandler\FieldHandlerBase;
  */
 class Price extends FieldHandlerBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function fromCellGetValue($cell) {
+    $value = $cell->getValue();
+    if (!$value) {
+      return;
+    }
+
+    $value_parts = explode(' ', $value);
+    return [
+      'number' => $value_parts[0],
+      'currency_code' => $value_parts[1],
+    ];
+  }
+
   /**
    * {@inheritdoc}
    */