Text string property editor: Data-type validation for max chars (fixes #18817)

[nielslyngsoe]

Fixes #18817

With the aspect that this guides the deveoper to do it right via the UI.

[Copilot]

Pull Request Overview

This PR adds input validation constraints to the TextBox property editor's "Maximum allowed characters" configuration field. The change prevents developers from entering invalid values (outside the 1-512 range) through the UI, addressing issue #18817.

Key Changes

• Added config array to the maxChars setting with min (1), max (512), and placeholder (512) constraints
• Removed the description text that previously indicated "If empty, 512 character limit"

[AndyButland]

I can verify this corrects the issue on the client, and I've added an equivalent server-side validation to to protect against direct requests to the management API.

This can be verified by a request using the Swagger UI and manipulating the provided maxChars value , e.g. for an existing textbox date type to:

PUT /umbraco/management/api/v1/data-type/{id}
{
   "name":"Test Box (50 Chars)",
   "editorAlias":"Umbraco.TextBox",
   "editorUiAlias":"Umb.PropertyEditorUi.TextBox",
   "values":[
      {
         "alias":"maxChars",
         "value":50
      },
      {
         "alias":"inputType",
         "value":"text"
      }
   ]
}

[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

[Zeegaan]

Back end looks good and works as intended, even got a little error in the backoffice 🚀