fix(core): update

ts_web/elements/dees-stepper.ts

@@ -14,6 +14,8 @@ import * as domtools from '@designestate/dees-domtools';
 export interface IStep {
   title: string;
   content: TemplateResult;
+  validationFunc?: (stepper: DeesStepper, htmlElement: HTMLElement) => Promise<any>;
+  validationFuncCalled?: boolean;
 }
 
 declare global {
@@ -200,6 +202,10 @@ export class DeesStepper extends DeesElement {
         easing: 'easeInOutQuint'
       }, stepperContainer);
     }
+    if (!this.selectedStep.validationFuncCalled && this.selectedStep.validationFunc) {
+      this.selectedStep.validationFuncCalled = true;
+      await this.selectedStep.validationFunc(this, selectedStepElement);
+    }
     this.scroller.to(scrollPosition);
   }