bludit/bl-plugins/twitter-cards/plugin.php

112 lines
2.8 KiB
PHP

<?php
class pluginTwitterCards extends Plugin {
public function init()
{
// Fields and default values for the database of this plugin
$this->dbFields = array(
'defaultImage'=>''
);
}
public function form()
{
global $Language;
$html = '<div>';
$html .= '<label>'.$Language->get('Default image').'</label>';
$html .= '<select name="defaultImage">';
$images = Filesystem::listFiles(PATH_UPLOADS);
foreach ($images as $image) {
$base = basename($image);
$html .= '<option value="'.$base.'" '.(($this->getValue('defaultImage')==$base)?'selected':'').'>'.$base.'</option>';
}
$html .= '</select>';
$html .= '</div>';
return $html;
}
public function siteHead()
{
global $Url;
global $Site;
global $WHERE_AM_I;
global $pages;
global $page;
$data = array(
'card' =>'summary',
'site' =>'',
'title' =>$Site->title(),
'description' =>$Site->description(),
'image' =>''
);
switch($WHERE_AM_I) {
// The user filter by page
case 'page':
$data['title'] = $page->title();
$data['description'] = $page->description();
$data['image'] = $page->coverImage($absolute=true);
$content = $page->content();
break;
// The user is in the homepage
default:
$content = '';
// The image it's from the first page
if(isset($pages[0]) ) {
$data['image'] = $pages[0]->coverImage($absolute=true);
$content = $pages[0]->content();
}
break;
}
$html = PHP_EOL.'<!-- Twitter Cards -->'.PHP_EOL;
$html .= '<meta property="twitter:card" content="'.$data['card'].'">'.PHP_EOL;
$html .= '<meta property="twitter:site" content="'.$data['site'].'">'.PHP_EOL;
$html .= '<meta property="twitter:title" content="'.$data['title'].'">'.PHP_EOL;
$html .= '<meta property="twitter:description" content="'.$data['description'].'">'.PHP_EOL;
// If the page doesn't have a coverImage try to get an image from the HTML content
if( empty($data['image']) ) {
// Get the image from the content
$src = $this->getImage($content);
if ($src!==false) {
$og['image'] = $src;
} else {
$og['image'] = DOMAIN_UPLOADS.$this->getValue('defaultImage');
}
}
$html .= '<meta property="twitter:image" content="'.$data['image'].'">'.PHP_EOL;
return $html;
}
// Returns the first image from the HTML content
private function getImage($content)
{
$dom = new DOMDocument();
$dom->loadHTML('<meta http-equiv="content-type" content="text/html; charset=utf-8">'.$content);
$finder = new DomXPath($dom);
$images = $finder->query("//img");
if($images->length>0) {
// First image from the list
$image = $images->item(0);
// Get value from attribute src
$imgSrc = $image->getAttribute('src');
// Returns the image src
return $imgSrc;
}
return false;
}
}