Add farm_map_wkt form element.

modules/core/map/src/Element/FarmMapWkt.php

@@ -0,0 +1,110 @@
+<?php
+
+namespace Drupal\farm_map\Element;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element\FormElement;
+
+/**
+ * Form element that returns WKT rendered in a map.
+ *
+ * @FormElement("farm_map_wkt")
+ */
+class FarmMapWkt extends FormElement {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getInfo() {
+    $class = static::class;
+    return [
+      '#input' => TRUE,
+      // @todo Does this have to return a tree structure?
+      '#tree' => TRUE,
+      '#process' => [
+        [$class, 'processElement'],
+      ],
+      '#pre_render' => [
+        [$class, 'preRenderGroup'],
+      ],
+      // @todo Add validation.
+//      '#element_validate' => [
+//        [$class, 'elementValidate'],
+//      ],
+      '#theme_wrappers' => ['fieldset'],
+      // Display descriptions above the map by default.
+      '#description_display' => 'before',
+      '#map_type' => 'geofield_widget',
+      '#display_raw_geometry' => TRUE,
+    ];
+  }
+
+  /**
+   * Generates the FarmMapWktform element.
+   *
+   * @param array $element
+   *   An associative array containing the properties and children of the
+   *   element. Note that $element must be taken by reference here, so processed
+   *   child elements are taken over into $form_state.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param array $complete_form
+   *   The complete form structure.
+   *
+   * @return array
+   *   The processed element.
+   */
+  public static function processElement(array $element, FormStateInterface $form_state, array &$complete_form) {
+
+    // Define the map render array.
+    // @todo Does this have to return a tree structure?
+    $element['#tree'] = TRUE;
+    $element['map'] = [
+      '#type' => 'farm_map',
+      '#map_type' => $element['#map_type'],
+      '#map_settings' => [
+        'behaviors' => [
+          'wkt' => [
+            'edit' => TRUE,
+            'zoom' => TRUE,
+          ],
+        ],
+      ],
+    ];
+
+    // Add a textarea for the WKT value.
+    $display_raw_geometry = $element['#display_raw_geometry'];
+    $element['value'] = [
+      '#type' => $display_raw_geometry ? 'textarea' : 'hidden',
+      '#title' => t('Geometry'),
+      '#attributes' => [
+        'data-map-geometry-field' => TRUE,
+      ],
+    ];
+
+    // Add default value if provided.
+    if (!empty($element['#default_value'])) {
+      $element['map']['#map_settings']['wkt'] = $element['#default_value'];
+      $element['value']['#default_value'] = $element['#default_value'];
+    }
+
+    // Return the element.
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
+    if ($input === FALSE) {
+      return $element['#default_value'] ?: [];
+    }
+
+    if ($input['value']) {
+      return $input['value'];
+    }
+
+    return NULL;
+  }
+
+}