Custom Question Type - How to register custom properties of an expression type

[JaneSjs]

T17578 - Custom Component not getting dynamic value on property https://surveyjs.answerdesk.io/internal/ticket/details/T17578

[andrewtelnov]

@RomanTsukanov @JaneSjs It should be the following code added into constructor: this.addExpressionProperty("productIdExpression", (obj: Base, res: any) => { this.productId = res; });

Thank you, Andrew

[JaneSjs]

@RomanTsukanov, please let me know what you think. I updated the Descriptive element demo and added a captionExpression property. It allows users to define an expression for the Caption property. View CodeSandbox

Now, the component has the following options:

• caption - a text property, localizable
• captionExpression - an expression property which defines a caption based on the expression result

[JaneSjs]

@RomanTsukanov suggested another option to update the documentation.