feat(modal): add modalDialogClass to modal-dialog div (#3826)

Co-authored-by: Michaela Tesařová <michaela.tesarova@ext.csas.cz>

src/modal/modal-config.ts

@@ -93,6 +93,11 @@ export interface NgbModalOptions {
    */
   windowClass?: string;
 
+  /**
+   * A custom class to append to the modal dialog.
+   */
+  modalDialogClass?: string;
+
   /**
    * A custom class to append to the modal backdrop.
    *
@@ -122,6 +127,7 @@ export class NgbModalConfig implements Required<NgbModalOptions> {
   scrollable: boolean;
   size: 'sm' | 'lg' | 'xl' | string;
   windowClass: string;
+  modalDialogClass: string;
   backdropClass: string;
 
   private _animation: boolean;

src/modal/modal-window.spec.ts

@@ -46,5 +46,14 @@ describe('ngb-modal-dialog', () => {
       expect(fixture.nativeElement.getAttribute('role')).toBe('dialog');
       expect(dialogEl.getAttribute('role')).toBe('document');
     });
+
+    it('should render modal dialog with a specified class', () => {
+      fixture.componentInstance.modalDialogClass = 'custom-dialog-class';
+      fixture.detectChanges();
+
+      const dialogEl: Element = fixture.nativeElement.querySelector('.modal-dialog');
+      expect(dialogEl).toHaveCssClass('modal-dialog');
+      expect(dialogEl).toHaveCssClass('custom-dialog-class');
+    });
   });
 });

src/modal/modal-window.ts

@@ -36,7 +36,7 @@ import {reflow} from '../util/util';
   },
   template: `
     <div #dialog [class]="'modal-dialog' + (size ? ' modal-' + size : '') + (centered ? ' modal-dialog-centered' : '') +
-     (scrollable ? ' modal-dialog-scrollable' : '')" role="document">
+     (scrollable ? ' modal-dialog-scrollable' : '') + (modalDialogClass ? ' ' + modalDialogClass : '')" role="document">
         <div class="modal-content"><ng-content></ng-content></div>
     </div>
     `,
@@ -59,6 +59,7 @@ export class NgbModalWindow implements OnInit,
   @Input() scrollable: string;
   @Input() size: string;
   @Input() windowClass: string;
+  @Input() modalDialogClass: string;
 
   @Output('dismiss') dismissEvent = new EventEmitter();