Panel.php

<?php
/**
 * @package   yii2-bootstrap-panel-widget
 * @author WeArDe <wearde.studio@gmail.com>
 * @link http://wearde.pp.ua
 * @version   1.0.0
 */

namespace amass\panel;

use yii\bootstrap\Widget;
use yii\helpers\Html;

class Panel extends Widget
{
    /**
     * @var array the HTML attributes for the widget container tag.
     * @see \yii\helpers\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $options = [];

    /** @var $headerTitle string the panel-title */
    public $headerTitle;
    /** @var $header bool showing header */
    public $header = true;
    /** @var $content mixed */
    public $content;
    /** @var $footer bool showing footer*/
    public $footer = false;
    /** @var $footerTitle string the panel-footer title */
    public $footerTitle;
    /** @var $type string Bootstrap Contextual Color Type default */
    public $type = 'default';

    /**
     * Bootstrap Contextual Color Types
     */
    const TYPE_DEFAULT = 'default'; // use default
    const TYPE_PRIMARY = 'primary';
    const TYPE_INFO = 'info';
    const TYPE_DANGER = 'danger';
    const TYPE_WARNING = 'warning';
    const TYPE_SUCCESS = 'success';

    /**
     * @inheritdoc
     */
    public function init()
    {
        $this->_initOptions();
        echo Html::beginTag('div',$this->options);

        $this->_initHeader();

        echo Html::beginTag('div',['class' => 'panel-body']);
        echo $this->content;
    }

    /**
     * @inheritdoc
     */
    public function run()
    {
        echo Html::endTag('div');
        $this->_initFooter();
        echo Html::endTag('div');
    }

    /**
     * Initialize bootstrap Panel styling
     */
    private function _initOptions()
    {
        if (!isset($this->options['id'])) {
            $this->options['id'] = $this->getId();
        }
        if (!isset($this->options['class'])) {
            $this->options['class'] = ' panel panel-'.$this->type;
        }
        $view = $this->getView();

        PanelAsset::register($view);
    }

    /**
     * Initialize Panel header
     */
    private function _initHeader(){

        if($this->header)
            echo Html::tag('div', Html::tag('h3',$this->headerTitle, ['class' => 'panel-title']), ['class' => 'panel-heading']);
    }

    /**
     * Initialize Panel header
     */
    private function _initFooter(){
        if($this->footer)
            echo Html::tag('div', $this->footerTitle, ['class' => 'panel-footer']);
    }
}