public function start_html() {
        if ($this->bar) {
            throw new \coding_exception('Already started');
        }
        $this->bar = new \progress_bar();
        $this->bar->create();
        echo \html_writer::start_div('wibbler');
    }
public function start_html() {
        if ($this->bar) {
            throw new \coding_exception('Already started');
        }
        $this->bar = new \progress_bar();
        $this->bar->create();
        echo \html_writer::start_div('wibbler');
    }
public function start_html ( ) { if ( $ this -> bar ) { throw new \ coding_exception ( 'Already started' ) ; } $ this -> bar = new \ progress_bar ( ) ; $ this -> bar -> create ( ) ; echo \ html_writer :: start_div ( 'wibbler' ) ; }
Starts to output progress.

Called in constructor and in update_progress if required.

@throws \coding_exception If already started
Starts to output progress .