fixate/pw-mvc-boilerplate

<?php
/**
 * OpenGraph trait
 *
 * In your controller set your options before initialising:
 *
 * $this->og_set_opt('site_name', $this->pages->get('/settings')->site_name);
 * OpenGraph::__ogInitialize($this);
 */
trait OpenGraph
{
    public static function __ogInitialize($obj)
    {
        $obj->helper('opengraph_meta_tags');
    }

    private $__og_opts = array(
        'site_name' => false,
        'title_get' => 'title',
        'canonical_url' => false,
        'object_type' => false,
        'object_type_default' => 'website',
        'description' => false,
        'description_get' => 'summary',
        'image_get' => 'image|images',
    );

    private $__og_custom_tags = [];

    protected function og_set_opt($opt, $value)
    {
        $this->__og_opts[$opt] = $value;
    }

    protected function og_add_tag($tag, $value)
    {
        $this->__og_custom_tags[$tag] = $value;
    }

    public function opengraph_meta_tags()
    {
        $image = $this->__og_get_prop('image', 'url');
        $tags = array(
            'site_name' => $this->__og_get_sitename(),
            'type' => $this->__og_opts['object_type'] ? $this->__og_opts['object_type'] : $this->__og_opts['object_type_default'],
            'title' => $this->__og_get_prop('title'),
            'url' => $this->__og_opts['canonical_url'] ? $this->__og_opts['canonical_url'] : $this->page->httpUrl,
            'description' => $this->__og_opts['description'] ? $this->_og_opts['description'] : $this->__og_get_prop('description'),
            'image' => $this->__og_image_meta($image),
        );

        $tags = array_merge($tags, $this->__og_custom_tags);

        return $this->__og_render_tags($tags);
    }

    private function __og_get_prop($prop, $field = null, $default = null)
    {
        $prop = $this->page->get($this->__og_opts["{$prop}_get"]);

        if ($prop && method_exists($this->page, $prop)) {
            if ($prop->count() == 0) {
                return $default;
            } elseif ($prop->count() > 1) {
                $prop = $this->__og_get_prop_array($prop, $field);
            } else {
                $prop = $prop->first();
            }
        }

        if (!$prop) {
            return $default;
        }

        return $prop;
    }

    private function __og_get_prop_array($prop, $field)
    {
        $prop_array = [];

        foreach ($prop as $p) {
            array_push($prop_array, $p->$field);
        }

        return $prop_array;
    }

    private function __og_get_sitename()
    {
        if ($this->__og_opts['site_name']) {
            return $this->__og_opts['site_name'];
        }

        return strlen($site_name = $this->pages->get('/settings')->site_name) !== 0 ? $site_name : null;
    }

    private function __og_image_meta($image)
    {
        $config = &$this->config;
        $protocol = $config->https ? 'https://' : 'http://';
        $hostname = $protocol . $config->httpHost;

        if ($image) {
            if (is_array($image)) {
                foreach ($image as &$item) {
                    $item = $hostname.$item;
                }

                return $image;
            }

            return $hostname.$image->url;
        }

        return;
    }

    private function __og_render_tags($tags)
    {
        $html = '';
        foreach ($tags as $name => $value) {
            if ($value !== null) {
                if (is_array($value)) {
                    foreach ($value as $v) {
                        $html .= $this->__og_tag_markup($name, $v);
                    }
                } else {
                    $html .= $this->__og_tag_markup($name, $value);
                }
            }
        }

        return $html;
    }

    private function __og_tag_markup($name, $value)
    {
        return "<meta property='og:{$name}' content='{$value}'/>";
    }
}