Property Editors: Add Missing Property Editor fallback

[lauraneto]

This pull request adjusts the code so that a new custom property editor UI is displayed when a property editor could not be found.
In order to achieve this, when requesting the data type, the original alias is returned, but the UI alias will be set to Umb.PropertyEditorUi.Missing.
In order to display the original value of the property in the UI, the management API now returns the original value, even when the editor could not be found. (previously it would ignore it and not return it)

UI

• When a property editor is missing, when the user opens a document containing that editor, a validation error will be displayed right away.

  

• When clicking on the details button, the user is shown a modal with additional details (exact text/content still to be determined) and the value that was stored for that property, independently of the type of data (number, text, JSON object).

  

• Attempting to save the page will fail and display an error notification.

  

• Opening the data types using the missing property editor will result in an empty property editor.

  

Tip

No editor is selected because the alias is not recognized by the front-end. Should we show something different? - Will be handled in a separate task.

• Opening the Info tab:

  

Warning

The Property Editor Schema Alias is empty, also because the editor is not recognized by the front-end. Is there a way to use the alias coming from the Management API instead or at least as a fallback? - Will be handled in a separate task.

Testing

There are multiple ways to simulate missing property editors:

• Adjust the alias of the data type editors in the database.
  • Open the umbracoDataType table and change the propertyEditorAlias in the data types you want to test. In my case I just added Missing. at the start of the alias.
• Install a community package that contains property editors (e.g. Contentment), and create a few data types using it. Then, uninstall the package.

1. Create a document type, allowed at root, with various types of properties.
2. Create a node using the created document type, fill in all of the properties and publish it.
3. Remove/delete the property editors. (using one of the options explained above)
4. Restart the application. (at least when changing directly in the database I noticed that some properties would still show as expected until I did a restart)
5. Go back to the content node and check the result.

[nielslyngsoe]

Regarding the information presented at the Data-Type Workspace, that will be resolved as part of another PR. So no worries covering that as part of this PR :-)

[Copilot]

Pull Request Overview

This pull request implements a fallback mechanism for handling missing property editors in Umbraco CMS. When a property editor is not found (e.g., after uninstalling a package), the system now displays a specialized "missing property editor" UI instead of failing or displaying no content.

Key changes include:

• Creation of a new MissingPropertyEditor class that preserves the original editor alias while providing a fallback UI
• Introduction of a frontend "missing property editor" UI component that shows validation errors and allows viewing stored data
• Removal of automatic conversion of missing editors to label editors, allowing the original data to be preserved and displayed

Reviewed Changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Umbraco.Core/PropertyEditors/MissingPropertyEditor.cs	Enhanced to accept original editor alias and provide proper value editor implementation
src/Umbraco.Core/Services/DataTypeService.cs	Removed automatic conversion of missing editors to label editors
src/Umbraco.Infrastructure/Persistence/Factories/DataTypeFactory.cs	Updated to create MissingPropertyEditor with original alias and set UI alias to missing editor
src/Umbraco.Infrastructure/Persistence/Repositories/Implement/DataTypeRepository.cs	Added IDataValueEditorFactory dependency for MissingPropertyEditor creation
src/Umbraco.Web.UI.Client/src/packages/property-editors/missing/	New frontend components for missing property editor UI, modal, and localization
src/Umbraco.Cms.Api.Management/Mapping/Content/ContentMapDefinition.cs	Updated content mapping to handle missing editors without returning null
Multiple mapping definition files	Added IDataValueEditorFactory dependency and obsolete constructor handling

[iOvergaard]

FE approved!

[kjac]

Looks great 💪