Encounter "Could not convert variant of type (Null) into type (boolean)" when using default constraints for attribute of type "xs:boolean"

[Chau Chee Yang]

Hi,

I am using XML Data Binding to generate the Delphi XML class from XSD
file. I found the Attribute's default value isn't implemented in the
wizard or is there any other alternative way to make it work?

For example, if I have the following attribute:

<xs:complexType name="Control">
<xs:attribute name="Caption" type="xs:string"/>
<xs:attribute name="Visible" type="xs:boolean" default="True"/>
</xs:compleType>

If my XML content is as follow:

<Control Caption="Test"/>

Later if I use the XML class:

Control.Caption will return "Test" but Control.Visible will always
return "Could not convert variant of type (Null) into type (boolean)"
error. If the insert the Visible attribute into XML:

<Control Caption="Test" Visible="True" />

then it works fine.

Please advice. Thank you.

--
Best regards,
Chau Chee Yang

E Stream Software Sdn Bhd
URL: www.sql.com.my
SQL Financial Accounting

[Khari Villela]

I think I ran into a similar issue. You have to include the unit Variants
and Delphi will be able to do the conversions correctly.

khariV

[khariv]

I had this same problem with Delphi 2005, but mine said cannot convert
Integer to variant. If you add Variants to the uses clause, the unit
should compile correctly.

--- posted by geoForum on http://delphi.newswhat.com