Q:

FXML set percentWidth on target node directly

Is it possible to set the percentWidth in the target node directly? I tried but im getting many errors if I do so:
<GridPane>
  <Button fx:id="node" id="node" text="fooBar"
     GridPane.columnIndex="1" GridPane.hgrow="always" GridPane.percentWidth="25"/>
</GridPane>

that is instead of:
   <columnConstraints>
          <ColumnConstraints percentWidth="25" />
    </columnConstraints>    

A:

No. There is no static setPercentWidth(Node,  ...) method in GridPane (see docs). 
It wouldn't really make sense to allow this anyway; it would enable you to set different percent widths on different nodes even if they were in the same column. Percent width is inherently a property of a column. 

