Only show field type options where there's a chance the data will map over to the new column type

brandonkelly · brandonkelly · commit 8870c8fb4a9a · 2017-02-03T16:59:00.000-08:00
Fixes #1 and #4
diff --git a/CHANGELOG-v3.md b/CHANGELOG-v3.md
@@ -12,6 +12,7 @@ Craft CMS 3.0 Working Changelog
 - The “Set status” batch element action now updates elements’ site statuses in addition to their global statuses, when setting the status to Enabled.
 - Editable tables now support a `radioMode` checkbox column option, which prevents more than one of the column’s checkboxes from being checked at a time.
 - `craft\helpers\Db::getNumericalColumnType()` no longer returns unsigned integer column types for MySQL.
+- The “Field Type” setting on Edit Field pages no longer shows field type options where there’s no chance the existing field data will map over.
 
 ### Removed
 - Removed the `afterSetStatus` event from `craft\elements\actions\SetStatus`.
diff --git a/src/controllers/FieldsController.php b/src/controllers/FieldsController.php
@@ -12,6 +12,7 @@
 use craft\base\FieldInterface;
 use craft\fields\MissingField;
 use craft\fields\PlainText;
+use craft\helpers\Db;
 use craft\helpers\UrlHelper;
 use craft\models\FieldGroup;
 use craft\web\Controller;
@@ -145,7 +146,40 @@ public function actionEditField(int $fieldId = null, FieldInterface $field = nul
         // Field types
         // ---------------------------------------------------------------------
 
-        $allFieldTypes = $fieldsService->getAllFieldTypes();
+        /** @var string[]|FieldInterface[] $allFieldTypes */
+
+        if (!$field->id) {
+            // Can be anything
+            $allFieldTypes = $fieldsService->getAllFieldTypes();
+        } else if ($field::hasContentColumn()) {
+            // Can only be field types with compatible column types
+            $allFieldTypes = $fieldsService->getAllFieldTypes();
+            $fieldColumnType = $field->getContentColumnType();
+
+            foreach ($allFieldTypes as $i => $class) {
+                if ($class === get_class($field)) {
+                    continue;
+                }
+
+                if (!$class::hasContentColumn()) {
+                    $compatible = false;
+                } else {
+                    /** @var FieldInterface $tempField */
+                    $tempField = new $class();
+                    $compatible = Db::areColumnTypesCompatible($fieldColumnType, $tempField->getContentColumnType());
+                }
+
+                if (!$compatible) {
+                    unset($allFieldTypes[$i]);
+                }
+            }
+
+            // Reset keys
+            $allFieldTypes = array_values($allFieldTypes);
+        } else {
+            // No column so no compatible field types
+            $allFieldTypes = [get_class($field)];
+        }
 
         // Make sure the selected field class is in there
         if (!in_array(get_class($field), $allFieldTypes, true)) {
