FlattenedObjectVars: Support selecting custom variables as columns

library/Icingadb/Model/Behavior/FlattenedObjectVars.php

@@ -4,11 +4,29 @@
 
 namespace Icinga\Module\Icingadb\Model\Behavior;
 
-use ipl\Orm\Contract\RewriteFilterBehavior;
+use Icinga\Module\Icingadb\Common\Auth;
+use Icinga\Module\Icingadb\Model\CustomvarFlat;
+use ipl\Orm\AliasedExpression;
+use ipl\Orm\ColumnDefinition;
+use ipl\Orm\Contract\QueryAwareBehavior;
+use ipl\Orm\Contract\RewriteColumnBehavior;
+use ipl\Orm\Query;
 use ipl\Stdlib\Filter;
 
-class FlattenedObjectVars implements RewriteFilterBehavior
+class FlattenedObjectVars implements RewriteColumnBehavior, QueryAwareBehavior
 {
+    use Auth;
+
+    /** @var Query */
+    protected $query;
+
+    public function setQuery(Query $query)
+    {
+        $this->query = $query;
+
+        return $this;
+    }
+
     public function rewriteCondition(Filter\Condition $condition, $relation = null)
     {
         $column = $condition->metaData()->get('columnName');
@@ -21,4 +39,33 @@ class FlattenedObjectVars implements RewriteFilterBehavior
             return Filter::all($nameFilter, $valueFilter);
         }
     }
+
+    public function rewriteColumn($column, $relation = null)
+    {
+        $subQuery = $this->query->createSubQuery(new CustomvarFlat(), $relation)
+            ->limit(1)
+            ->columns('flatvalue')
+            ->filter(Filter::equal('flatname', $column));
+
+        $this->applyRestrictions($subQuery);
+
+        $alias = $this->query->getDb()->quoteIdentifier([str_replace('.', '_', $relation) . "_$column"]);
+
+        list($select, $values) = $this->query->getDb()->getQueryBuilder()->assembleSelect($subQuery->assembleSelect());
+        return new AliasedExpression($alias, "($select)", null, ...$values);
+    }
+
+    public function rewriteColumnDefinition(ColumnDefinition $def, string $relation): void
+    {
+        $parts = explode('.', substr($relation, 0, -5));
+        $objectType = array_pop($parts);
+
+        // Programmatically translated since the full definition is available in class ObjectSuggestions
+        $def->setLabel(sprintf(t(ucfirst($objectType) . ' %s', '..<customvar-name>'), $def->getName()));
+    }
+
+    public function isSelectableColumn(string $name): bool
+    {
+        return true;
+    }
 }