add getters

src/Umbraco.Web.UI.Client/src/packages/documents/documents/components/input-document/input-document.element.ts

@@ -96,6 +96,9 @@ export class UmbInputDocumentElement extends FormControlMixin(UmbLitElement) {
 		// Its with full purpose we don't call super.value, as thats being handled by the observation of the context selection.
 		this.selectedIds = splitStringToArray(idsString);
 	}
+	public get value() {
+		return this.selectedIds.join(',');
+	}
 
 	@state()
 	private _editDocumentPath = '';

src/Umbraco.Web.UI.Client/src/packages/media/media/components/input-media/input-media.element.ts

@@ -96,6 +96,9 @@ export class UmbInputMediaElement extends FormControlMixin(UmbLitElement) {
 		// Its with full purpose we don't call super.value, as thats being handled by the observation of the context selection.
 		this.selectedIds = splitStringToArray(idsString);
 	}
+	public get value() {
+		return this.selectedIds.join(',');
+	}
 
 	@state()
 	private _editMediaPath = '';