Legend and On click settings

Allows users to show/hide lines by clicking on the legend

{
  "elements": [
    {
      "type": "line",
      "values": [
        0,
        1,
        2,
        3,
        4,
        5,
        6,
        7,
        8,
        9,
        10
      ],
      "text": "line 1",
      "id": 1,
      "colour": "#ff0000",
      "key-on-click": "toggle-visibility"
    },
    {
      "type": "line",
      "values": [
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5
      ],
      "text": "line 2",
      "id": 2,
      "colour": "#00ff00",
      "key-on-click": "toggle-visibility"
    },
    {
      "type": "line",
      "values": [
        10,
        9,
        8,
        7,
        6,
        5,
        4,
        3,
        2,
        1,
        0
      ],
      "id": 1,
      "colour": "#0000ff",
      "key-on-click": "toggle-visibility"
    }
  ],
  "legend": {
    "visible": true
  }
}

$chart = new open_flash_chart();
 
$line_dot = new line();
$line_dot->set_values( array(0,1,2,3,4,5,6,7,8,9,10));
$line_dot->set_text( "line 1" );
$line_dot->set_group_id( 1 );
$line_dot->set_colour( '#ff0000' );
$line_dot->set_key_on_click( "toggle-visibility" );
$chart->add_element( $line_dot );
 
$line_dot = new line();
$line_dot->set_values( array(5,5,5,5,5,5,5,5,5,5,5));
$line_dot->set_text( "line 2" );
$line_dot->set_group_id( 2 );
$line_dot->set_colour( '#00ff00' );
$line_dot->set_key_on_click( "toggle-visibility" );
$chart->add_element( $line_dot );
 
$line_dot = new line();
$line_dot->set_values( array(10,9,8,7,6,5,4,3,2,1,0));
$line_dot->set_group_id( 1 );
$line_dot->set_colour( '#0000ff' );
$line_dot->set_key_on_click( "toggle-visibility" );
$chart->add_element( $line_dot );
 
$legend = new legend();
$legend->set_visible(true);
$chart->set_legend( $legend );
 
echo $chart->toPrettyString();