Example of hierarchy add-on use in agile toolkit

View_CommentTree.php

<?php
class View_CommentTree extends hierarchy\View_Tree {
    function init(){
        parent::init();
        $this->time_ctl=$this->add('Controller_RoundTiming');
    }
    function formatRow(){
        $this->current_row['added']=$this->time_ctl->fancy_datetime($this->current_row['added']).' ago';
        $this->current_row_html['descr']=nl2br($this->makeUrls($this->current_row['descr']));
        $this->current_row_html['profile_link']=
                $this->api->url('profile/'.$this->current_row['profile_id'],array('endowment_id'=>null));
    }
    function renderModel($m){
        $el=$m->leftJoin('element','profile_id');

        $el->addField('profile_name','name');

        $image=$m->add('filestore/Field_Image', array(
            'name'=>'owner_picture_id',
            'use_model'=>'Image_Element'
        ))->from($el)->actual('picture_id');

        $image
            ->addThumb('thumb', 'thumb_64')
            ;

        return parent::renderModel($m);
    }
    function makeUrls($text) {
        $text = preg_replace(
            array(
                '/((https:\/\/|http:\/\/)\S*)/',
                '/(\s)((www.)\S*)/',
            ),
            array(
                '<a href="$1" target="_blank">$0</a>',
                '$1<a href="http://$2" target="_blank">$2</a>',
            ),
            $text
        );
        return $text;
    }
}

Model definition:

    $this->setController('hierarchy/Table')->useField('parent_comment_id');
    $this->hasOne('Element')->mandatory(true)->caption('Commented on');
    $this->hasOne('Profile','profile_id')->mandatory(true)->caption('Author');

    $this->addField('descr')->type('text');
    $this->addField('added')->defaultValue(date('Y-m-d H:i:s'));