expandable FK columns

packages/datalib/src/GridConfig.ts

@@ -1,3 +1,23 @@
+import { DisplayColumn } from './GridDisplay';
+
 export interface GridConfig {
   hiddenColumns: string[];
+  expandedColumns: string[];
+}
+
+export interface GridCache {
+  subcolumns: { [column: string]: DisplayColumn[] };
+}
+
+export function createGridConfig(): GridConfig {
+  return {
+    hiddenColumns: [],
+    expandedColumns: [],
+  };
+}
+
+export function createGridCache(): GridCache {
+  return {
+    subcolumns: {},
+  };
 }