uppercase form textfield I want to have a form textfield automatically uppercase the text entered as it is typed in.  I was hoping that there was as set-able property that would allow for this but I’m unable to find one.  


  $form['elementName'] = array(
            '#type' => 'textfield',
            '#title' => $this->t('Address'),...
  )


The searches I have done so far point to the use of  ‘Plugins.’  However if there is a simple(er) solution I prefer that.  Any ideas appreciated;
However if there is a simple(er) solution I prefer that.  


Sorry, maybe I going too deep, but the most simpler solution that you can use just for display is a CSS solution.

Based in your example:

input[name='elementName'] {
  text-transform: uppercase;
}


That's it, any char will be uppercase in your textfield. If need store in uppercase, just change case before save.