UI fixes

frontend/src/app/features/content/shared/preview-button.component.ts

@@ -96,7 +96,6 @@ export class PreviewButtonComponent extends StatefulComponent<State> implements
             const state = { ...s };
 
             const keys = Object.keys(this.schema.previewUrls);
-
             state.previewNameSelected = selectedName;
             state.previewNamesMore = keys.removed(selectedName).sorted();
 

frontend/src/app/features/content/shared/references/references-editor.component.html

@@ -5,7 +5,7 @@
         </button>
     </div>
     <div class="col" [class.disabled]="snapshot.isDisabled">
-        <button class="btn btn-outline-secondary btn-dashed btn-block" (click)="contentSelectorDialog.show()">
+        <button class="btn btn-outline-secondary btn-dashed btn-block" (click)="contentSelectorDialog.show()" type="button">
             {{ "contents.referencesSelectExisting" | sqxTranslate }}
         </button>
     </div>

frontend/src/app/shared/state/contents.forms.spec.ts

@@ -397,6 +397,23 @@ describe('GetContentValue', () => {
         });
     });
 
+    it('should resolve value from invariant field as zero', () => {
+        const content: any = {
+            data: {
+                field1: {
+                    iv: 0,
+                },
+            },
+        };
+
+        const result = getContentValue(content, language, fieldInvariant);
+
+        expect(result).toEqual({
+            value: 0,
+            formatted: '0',
+        });
+    });
+
     it('should resolve value from localized field', () => {
         const content: any = {
             data: {

frontend/src/app/shared/state/contents.forms.visitors.ts

@@ -48,12 +48,11 @@ export function getContentValue(content: ContentDto, language: LanguageDto, fiel
     const actualReference = getValue(content.referenceData, language, field, true);
     const actualValue = getValue(content.data, language, field);
 
-    if (!actualReference && !actualValue) {
+    if (Types.isUndefined(actualReference) && Types.isUndefined(actualValue)) {
         return { value: actualValue, formatted: '' };
     }
 
     const formatted = FieldFormatter.format(field, actualValue, actualReference, allowHtml);
-
     return { value: actualValue, formatted };
 }