The AddAttribute(x, opts) calling sequence adds attributes to a previously constructed element.  This is an advanced feature.  No post-processing is performed. Therefore, shortcuts cannot be used.

The AddAttribute command must be used on constructed elements prior to a call to the Maplet command and can only be used directly on objects to which it is applied.

$\mathrm{with}\left(\mathrm{Maplets}\left[\mathrm{Elements}\right]\right)\:$

$b≔\mathrm{Button}\left(''Hello''\,'\mathrm{onclick}'='\mathrm{A1}'\right)$

$b≔\mathrm{Maplets}:-\mathrm{Elements}:-\mathrm{com.maplesoft.maplets.elements.MButton}\left(''onclick''=''REF''\left(''A1''\right)\,''caption''=''Hello''\,''enabled''=''true''\,''halign''=''center''\,''valign''=''center''\,''visible''=''true''\right)$

$\mathrm{Maplets}\left[\mathrm{Tools}\right]\left[\mathrm{AddAttribute}\right]\left(b\,'\mathrm{reference}'='\mathrm{B1}'\,'\mathrm{color}'=''\#FF00FF''\right)$

$\mathrm{Maplets}:-\mathrm{Elements}:-\mathrm{com.maplesoft.maplets.elements.MButton}\left(''reference''=''B1''\,''color''=''\#FF00FF''\,''onclick''=''REF''\left(''A1''\right)\,''caption''=''Hello''\,''enabled''=''true''\,''halign''=''center''\,''valign''=''center''\,''visible''=''true''\right)$