png32topng24.sketchplugin

var openDialog = NSOpenPanel.openPanel();
openDialog.setCanChooseFiles(true);
openDialog.setCanChooseDirectories(false);
openDialog.setAllowsMultipleSelection(false);
openDialog.setCanCreateDirectories(false);
openDialog.setTitle('Choose File');
if( openDialog.runModal() == NSOKButton ) {
	var fileURL = openDialog.URLs().firstObject();
} else {
	return false;
}

var regexp = new RegExp( 'file://', 'ig' );
var fileURL = fileURL.replace( regexp, '' );
var option = 'mogrify "' + fileURL + '" -background white -alpha remove';
var task = NSTask.new();
task.setLaunchPath( '/bin/bash' );
task.setArguments(['-c', option]);
task.launch();