Artist draws values for all properties, even if they are not set

[activefx]

When creating a representation for an object, the artist draws all properties, including them even if they are null. This interferes with some endpoints, as they may try to lookup a value if the key is present. For example, file may be an optional property, but if the key is present the server may try to open that file and return an error.

{name:"test",file:null}

The artist should exclude properties without values.