Fix: Change back and next button labels when at start / end (fixes #310)

js/NarrativeView.js

@@ -254,32 +254,31 @@ class NarrativeView extends ComponentView {
     const globals = Adapt.course.get('_globals');
     const narrativeGlobals = globals._components._narrative;
 
-    let prevTitle = isAtStart ? '' : this.model.getItem(index - 1).get('title');
-    let nextTitle = isAtEnd ? '' : this.model.getItem(index + 1).get('title');
+    const prevItem = !isAtStart && this.model.getItem(index - 1);
+    const nextItem = !isAtEnd && this.model.getItem(index + 1);
 
-    let backItem = isAtStart ? null : index;
-    let nextItem = isAtEnd ? null : index + 2;
+    const prevTitle = prevItem ? prevItem.get('title') : '';
+    const prevBody = prevItem ? prevItem.get('body') : '';
 
-    if (isAtStart) {
-      prevTitle = this.model.getItem(totalItems - 1).get('title');
-      backItem = totalItems;
-    }
-    if (isAtEnd) {
-      nextTitle = this.model.getItem(0).get('title');
-      nextItem = 1;
-    }
+    const nextTitle = nextItem ? nextItem.get('title') : '';
+    const nextBody = nextItem ? nextItem.get('body') : '';
+
+    const prevItemNumber = isAtStart ? null : index;
+    const nextItemNumber = isAtEnd ? null : index + 2;
 
     const backLabel = compile(narrativeGlobals.previous, {
       _globals: globals,
       title: prevTitle,
-      itemNumber: backItem,
+      body: prevBody,
+      itemNumber: prevItemNumber,
       totalItems
     });
 
     const nextLabel = compile(narrativeGlobals.next, {
       _globals: globals,
       title: nextTitle,
-      itemNumber: nextItem,
+      body: nextBody,
+      itemNumber: nextItemNumber,
       totalItems
     });
 

properties.schema

@@ -15,15 +15,15 @@
     "previous": {
       "type": "string",
       "required": true,
-      "default": "{{#if title}}Back to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.previous}}{{/if}} (item {{itemNumber}} of {{totalItems}})",
+      "default": "{{#any title body}}{{#if title}}Back to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.previous}}{{/if}} (item {{itemNumber}} of {{totalItems}}){{else}}{{_globals._accessibility._ariaLabels.previous}}{{/any}}",
       "inputType": "Text",
       "validators": [],
       "translatable": true
     },
     "next": {
       "type": "string",
       "required": true,
-      "default": "{{#if title}}Forward to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.next}}{{/if}} (item {{itemNumber}} of {{totalItems}})",
+      "default": "{{#any title body}}{{#if title}}Forward to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.next}}{{/if}} (item {{itemNumber}} of {{totalItems}}){{else}}{{_globals._accessibility._ariaLabels.next}}{{/any}}",
       "inputType": "Text",
       "validators": [],
       "translatable": true

schema/course.schema.json

@@ -32,15 +32,15 @@
                     "previous": {
                       "type": "string",
                       "title": "Previous",
-                      "default": "{{#if title}}Back to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.previous}}{{/if}} (item {{itemNumber}} of {{totalItems}})",
+                      "default": "{{#any title body}}{{#if title}}Back to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.previous}}{{/if}} (item {{itemNumber}} of {{totalItems}}){{else}}{{_globals._accessibility._ariaLabels.previous}}{{/any}}",
                       "_adapt": {
                         "translatable": true
                       }
                     },
                     "next": {
                       "type": "string",
                       "title": "Next",
-                      "default": "{{#if title}}Forward to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.next}}{{/if}} (item {{itemNumber}} of {{totalItems}})",
+                      "default": "{{#any title body}}{{#if title}}Forward to {{{title}}}{{else}}{{_globals._accessibility._ariaLabels.next}}{{/if}} (item {{itemNumber}} of {{totalItems}}){{else}}{{_globals._accessibility._ariaLabels.next}}{{/any}}",
                       "_adapt": {
                         "translatable": true
                       }