Adding a tag in the header.php for meta tags openGrah, hreflang and canonical

In order to improve the SEO : adding tag in the header.php for meta tags openGrah, hreflang and canonical

<!--?php if(isset($this--->vars['meta_og'])):?><br />vars['meta_og']['type']?>"/><br />vars['meta_og']['url']?>"/><br />vars['meta_og']['image']?>"/><br />vars['meta_og']['title']?>"/><br />vars['meta_og']['description']?>"/><br /><!--?php endif ?--><br /><br /><br /><!--?php if(isset($this--->vars['meta']['hreflang'])) echo $this->vars['meta']['hreflang']; ?><br /><br /><!--?php if(isset($this--->vars['meta']['canonical'])):?><br /><br /><!--?php endif ?-->