Инструменты пользователя
Step6. Creating newsline RSS-feed
RSS - is an essential feature of any frequently updated web project. At this page we will show you how to create RSS feeds with Limb3.
Let's suppose we need to create RSS-feed with the latest news. To do so we'll create last-news-feed.php script and will put it into crud/www folder of our project.
The algorithm of last-news-feed.php is the following:
- get the latest news
- make absolute hrefs for news pages
- push news record set to WACT template and convert it into XML
- return RSS XML to client.
The source code of last-news-feed.php:
<?php require_once('../setup.php'); require_once('limb/web_app/src/template/lmbWactTemplate.class.php'); require_once('limb/core/src/lmbCollection.class.php'); require_once('src/model/News.class.php'); $template = new lmbWactTemplate('rss/last_news.rss'); $template->setChildDataSet('last_news', getNewsDataSetWithFullPaths()); header("Content-Type: application/xml"); $template->display(); function getNewsDataSetWithFullPaths() { $news_rs = lmbActiveRecord :: find('News', array('sort' => array('date' => 'DESC', 'title' => 'ASC'), 'limit' => 5)); $result = array(); foreach($news_rs as $news) { $news_id = $news->getId(); $result[$news_id] = $news->export(); $result[$news_id]['path'] = 'http://' . $_SERVER['HTTP_HOST'] . '/news/detail/' . $news_id; } return new lmbCollection($result); } ?>
Let's explain what happens in the script above. The most interesting part is getNewsDataSetWithFullPaths() function where news are loaded from database using lmbActiveRecord :: find() method. News record set is sorted by «date» and «title» and limited with 5 elements. lmbActiveRecord :: find() method accepts class name of objects to be loaded and an array of parameters to be applied to the retrieved record set.
By the way, lmbActiveRecord :: find(..) part can be rewritten in a slightly different way using methods chaining:
$news_rs = lmbActiveRecord :: find('News')->sort(array('date' => 'DESC', 'title' => 'ASC'))->paginate(0, 5);
Once news are loaded we need to create a collection that contains news data as well as absolute paths to every news page:
$result = array(); foreach($news_rs as $news) { $news_id = $news->getId(); $result[$news_id] = $news->export(); $result[$news_id]['path'] = 'http://' . $_SERVER['HTTP_HOST'] . '/news/detail/' . $news_id; } return new lmbCollection($result);
lmbCollection class is used above to create an iterator to be passed into WACT view.
Then WACT instance is created using rss/last_news.rss template followed by news collection passed into «last_news» runtime component of <list:list> tag:
$template = new lmbWactTemplate('rss/last_news.rss'); $template->setChildDataSet('last_news', getNewsDataSetWithFullPaths());
Here is rss/last_news.rss template contents:
<!--l version="1.0" encoding="utf-8"--> <!DOCTYPE rss [<!ENTITY % HTMLlat1 PUBLIC "-//W3C//ENTITIES Latin 1 for XHTML//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml-lat1.ent">]> <rss version="0.92" xml:base="http://tutorial.dbrain.bit"> <channel> <title>YourDomain.com last news</title> <language>en</language> <list:list id='last_news'> <list:item> <item> <title>{$title}</title> <link>{$path}</link> <description> {$annotation} </description> <pubDate> {$date} </pubDate> </item> </list:item> </list:list> </channel> </rss>
Please note how proper mime type is sent to the client:
header("Content-Type: application/xml");
Finally let's add a link to this RSS-feed into crud/template/page.html template:
<html> <head> <title>Limb3 tutorial</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> </head> <body bgcolor="#FFFFFF" text="#000000" > <a href="/last-news-feed.php">RSS-feed</a> <hr /> <core:PLACEHOLDER id="page_placeholder"/> </body> </html>
What's next?
Инструменты страницы
Обсуждение