feat(IgxColumnGroup): add collapsible indicator template directive #3343

Author: ddincheva

projects/igniteui-angular/src/lib/grids/columns/column.module.ts

@@ -7,6 +7,7 @@ import {
     IgxCellFooterTemplateDirective,
     IgxCellHeaderTemplateDirective,
     IgxCellTemplateDirective,
+    IgxCollapsibleIndicatorTemplateDirective,
     IgxFilterCellTemplateDirective
 } from './templates.directive';
 
@@ -18,6 +19,7 @@ import {
         IgxCellHeaderTemplateDirective,
         IgxCellFooterTemplateDirective,
         IgxCellEditorTemplateDirective,
+        IgxCollapsibleIndicatorTemplateDirective,
         IgxColumnComponent,
         IgxColumnGroupComponent,
         IgxColumnLayoutComponent
@@ -33,6 +35,7 @@ import {
         IgxCellHeaderTemplateDirective,
         IgxCellFooterTemplateDirective,
         IgxCellEditorTemplateDirective,
+        IgxCollapsibleIndicatorTemplateDirective,
         IgxColumnComponent,
         IgxColumnGroupComponent,
         IgxColumnLayoutComponent

projects/igniteui-angular/src/lib/grids/columns/templates.directive.ts

@@ -42,3 +42,11 @@ export class IgxCellEditorTemplateDirective {
 
     constructor(public template: TemplateRef<any>) { }
 }
+
+@Directive({
+    selector: '[igxCollapsibleIndicator]'
+})
+export class IgxCollapsibleIndicatorTemplateDirective {
+
+    constructor(public template: TemplateRef<any>) { }
+}