Feat: Option to remove back button:

- This feature allows you to remove the back button on a given page with
  the following:

  "disableBackLink": true

- This was added since the magic link feature redirects back to a form but
  still shows a back button

Author: SullyK

model/src/data-model/types.ts

@@ -12,6 +12,7 @@ export type Link = Next;
 export interface Page {
   title: string;
   path: string;
+  disableBackLink?: boolean;
   controller: string;
   components?: ComponentDef[];
   section?: string; // the section ID

model/src/schema/schema.ts

@@ -119,6 +119,7 @@ const pageSchema = joi.object().keys({
   repeatField: joi.string().optional(),
   options: joi.object().optional(),
   backLinkFallback: joi.string().optional(),
+  disableBackLink: joi.bool().optional(),
 });
 
 const startNavigationLinkSchema = joi.object().keys({

runner/src/server/plugins/engine/pageControllers/PageControllerBase.ts

@@ -57,6 +57,7 @@ export class PageControllerBase {
   hasFormComponents: boolean;
   hasConditionalFormComponents: boolean;
   backLinkFallback?: string;
+  disableBackLink?: boolean;
 
   // TODO: pageDef type
   constructor(model: FormModel, pageDef: { [prop: string]: any } = {}) {
@@ -73,6 +74,9 @@ export class PageControllerBase {
     this.condition = pageDef.condition;
     this.repeatField = pageDef.repeatField;
     this.backLinkFallback = pageDef.backLinkFallback;
+    this.disableBackLink = pageDef.disableBackLink;
+    this.disableSingleComponentAsHeading =
+      pageDef.disableSingleComponentAsHeading;
 
     // Resolve section
     this.section = model.sections?.find(
@@ -559,10 +563,14 @@ export class PageControllerBase {
 
       await cacheService.mergeState(request, { progress });
 
-      viewModel.backLink =
-        progress[progress.length - 2] ?? this.backLinkFallback;
+      if (this.disableBackLink) {
+        viewModel.backLink = undefined; 
+      } else {
+        viewModel.backLink = progress[progress.length - 2] ?? this.backLinkFallback;
+      }
 
       viewModel.allowExit = this.model.allowExit;
+
       return h.view(this.viewName, viewModel);
     };
   }
@@ -876,7 +884,12 @@ export class PageControllerBase {
   private renderWithErrors(request, h, payload, num, progress, errors) {
     const viewModel = this.getViewModel(payload, num, errors);
 
-    viewModel.backLink = progress[progress.length - 2] ?? this.backLinkFallback;
+      if (this.disableBackLink) {
+      viewModel.backLink = undefined;
+    } else {
+      viewModel.backLink = progress[progress.length - 2] ?? this.backLinkFallback;
+    }
+
     this.setPhaseTag(viewModel);
     this.setFeedbackDetails(viewModel, request);
     viewModel.allowExit = this.model.allowExit;