From d5144540f73f0c59e40079e8a2f4871702403a1e Mon Sep 17 00:00:00 2001
From: Mads Rasmussen <madsr@hey.com>
Date: Wed, 11 Dec 2024 12:09:17 +0100
Subject: [PATCH] prevent the block list editor from setting an empty value on
 startup

---
 .../property-editor-ui-block-list.element.ts  | 41 +++++++++++++------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/src/Umbraco.Web.UI.Client/src/packages/block/block-list/property-editors/block-list-editor/property-editor-ui-block-list.element.ts b/src/Umbraco.Web.UI.Client/src/packages/block/block-list/property-editors/block-list-editor/property-editor-ui-block-list.element.ts
index 1559e4899a..d608e3c373 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/block/block-list/property-editors/block-list-editor/property-editor-ui-block-list.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/block/block-list/property-editors/block-list-editor/property-editor-ui-block-list.element.ts
@@ -56,15 +56,19 @@ export class UmbPropertyEditorUIBlockListElement
 
 	//#catalogueModal: UmbModalRouteRegistrationController<typeof UMB_BLOCK_CATALOGUE_MODAL.DATA, undefined>;
 
-	private _value: UmbBlockListValueModel = {
-		layout: {},
-		contentData: [],
-		settingsData: [],
-		expose: [],
-	};
+	private _value: UmbBlockListValueModel | undefined = undefined;
+
+	#lastValue: UmbBlockListValueModel | undefined = undefined;
 
 	@property({ attribute: false })
 	public override set value(value: UmbBlockListValueModel | undefined) {
+		this.#lastValue = value;
+
+		if (!value) {
+			this._value = undefined;
+			return;
+		}
+
 		const buildUpValue: Partial<UmbBlockListValueModel> = value ? { ...value } : {};
 		buildUpValue.layout ??= {};
 		buildUpValue.contentData ??= [];
@@ -188,13 +192,24 @@ export class UmbPropertyEditorUIBlockListElement
 					this.#managerContext.exposes,
 				]).pipe(debounceTime(20)),
 				([layouts, contents, settings, exposes]) => {
-					this._value = {
-						...this._value,
-						layout: { [UMB_BLOCK_LIST_PROPERTY_EDITOR_SCHEMA_ALIAS]: layouts },
-						contentData: contents,
-						settingsData: settings,
-						expose: exposes,
-					};
+					if (layouts.length === 0) {
+						this._value = undefined;
+					} else {
+						this._value = {
+							...this._value,
+							layout: { [UMB_BLOCK_LIST_PROPERTY_EDITOR_SCHEMA_ALIAS]: layouts },
+							contentData: contents,
+							settingsData: settings,
+							expose: exposes,
+						};
+					}
+
+					// If we don't have a value set from the outside or an internal value, we don't want to set the value.
+					// This is added to prevent the block list from setting an empty value on startup.
+					if (this.#lastValue === undefined && this._value === undefined) {
+						return;
+					}
+
 					context.setValue(this._value);
 				},
 				'motherObserver',