FIX Respect searchable_fields

src/Forms/GridField/GridFieldFilterHeader.php

@@ -254,21 +254,25 @@ public function getManipulatedData(GridField $gridField, SS_List $dataList)
     public function canFilterAnyColumns($gridField)
     {
         $list = $gridField->getList();
-
-        if (!$this->checkDataType($list)) {
+        if (!($list instanceof Filterable) || !$this->checkDataType($list)) {
             return false;
         }
-
-        $columns = $gridField->getColumns();
-        foreach ($columns as $columnField) {
-            $metadata = $gridField->getColumnMetadata($columnField);
-            $title = $metadata['title'];
-
-            if ($title && $list->canFilterBy($columnField)) {
+        $modelClass = $gridField->getModelClass();
+        // note: searchableFields() will return summary_fields if there are no searchable_fields on the model
+        $searchableFields = array_keys($modelClass::singleton()->searchableFields());
+        $summaryFields = array_keys($modelClass::singleton()->summaryFields());
+        sort($searchableFields);
+        sort($summaryFields);
+        // searchable_fields has been explictily defined i.e. searchableFields() is not falling back to summary_fields
+        if ($searchableFields !== $summaryFields) {
+            return true;
+        }
+        // we have fallen back to summary_fields, check they are filterable
+        foreach ($searchableFields as $searchableField) {
+            if ($list->canFilterBy($searchableField)) {
                 return true;
             }
         }
-
         return false;
     }
 

tests/php/Forms/GridField/GridFieldFilterHeaderTest.php

@@ -182,4 +182,30 @@ public function testCustomSearchField()
 
         $this->assertEquals('ReallyCustomSearch', $this->component->getSearchField());
     }
+
+    public function testCanFilterAnyColumns()
+    {
+        $gridField = $this->gridField;
+        $filterHeader = $gridField->getConfig()->getComponentByType(GridFieldFilterHeader::class);
+
+        // test that you can filter by something if searchable_fields is not defined
+        // silverstripe will scaffold db columns that are in the gridfield to be
+        // searchable by default
+        Config::modify()->remove(Team::class, 'searchable_fields');
+        $this->assertTrue($filterHeader->canFilterAnyColumns($gridField));
+
+        // test that you can filterBy if searchable_fields is defined
+        Config::modify()->set(Team::class, 'searchable_fields', ['Name']);
+        $this->assertTrue($filterHeader->canFilterAnyColumns($gridField));
+
+        // test that you can filterBy if searchable_fields even if it is not a legit field
+        // this is because we're making a blind assumption it will be filterable later in a SearchContext
+        Config::modify()->set(Team::class, 'searchable_fields', ['WhatIsThis']);
+        $this->assertTrue($filterHeader->canFilterAnyColumns($gridField));
+
+        // test that you cannot filter by non-db field when it falls back to summary_fields
+        Config::modify()->remove(Team::class, 'searchable_fields');
+        Config::modify()->set(Team::class, 'summary_fields', ['MySummaryField']);
+        $this->assertFalse($filterHeader->canFilterAnyColumns($gridField));
+    }
 }

tests/php/Forms/GridField/GridFieldFilterHeaderTest/Team.php

@@ -24,4 +24,9 @@ class Team extends DataObject implements TestOnly
         'Cheerleader' => Cheerleader::class,
         'CheerleadersMom' => Mom::class
     ];
+
+    public function getMySummaryField()
+    {
+        return 'MY SUMMARY FIELD';
+    }
 }