View source for Clickable button/iconclass

{{#if:{{{3|}}}
|<!-- a text was specified
-->{{#if:{{{1|}}}
    |<!-- a primary icon was specified -->{{#if:{{{2|}}}
      |<!-- a secondary icon was specified --> ui-button-text-icons
      |<!-- no secondary icon was specified --> ui-button-text-icon-primary
    }}
    |<!-- no primary icon specified --> {{#if:{{{2|}}}
      |<!-- a secondary icon was specified --> ui-button-text-icon-secondary
      |<!-- no secondary icon was specified --> ui-button-text-only
    }}
  }}
|<!-- no text was specified
-->{{#if:{{{1|}}}
    |<!-- a primary icon was specified -->{{#if:{{{2|}}}
      |<!-- a secondary icon was specified --> ui-button-icons-only
      |<!-- no secondary icon was specified --> ui-button-icon-only
    }}
    |<!-- no primary icon specified --> {{#if:{{{2|}}}
      |<!-- a secondary icon was specified --> ui-button-icon-only
      |<!-- no secondary icon was specified --> error
    }}
  }}
}}