How to use MultiFileItem?

[hakito]

Hi i searched the forum and read the documentation about MultiFileItem

But i'm still confused about how to use it. The doc says:

in the DynamicForm bound to the "master" DataSource, declare a field with editorType:"MultiFieldItem" and a dataSource property set to the ID of the "detail" DataSource

So here is what i do:

DynamicForm df = new DynamicForm();
df.setDataSource("master");
FieldItem fi = new FieldItem("fileid");
fi.setAttribute("editorType", "MultiFileItem");
fi.setAttribute("dataSource", "detail");

So how do i declare this field in the DynamicForm df?