Best way to parse RSS/Atom feeds with PHP

Question

I'm currently using Magpie RSS but it sometimes falls over when the RSS or Atom feed isn't well formed. Are there any other options for parsing RSS and Atom feeds with PHP?

Solution 1

Your other options include:

• SimplePie
• Last RSS
• PHP Universal Feed Parser

Solution 2

I've always used the SimpleXML functions built in to PHP to parse XML documents. It's one of the few generic parsers out there that has an intuitive structure to it, which makes it extremely easy to build a meaningful class for something specific like an RSS feed. Additionally, it will detect XML warnings and errors, and upon finding any you could simply run the source through something like HTML Tidy (as ceejayoz mentioned) to clean it up and attempt it again.

Consider this very rough, simple class using SimpleXML:

class BlogPost
{
    var $date;
    var $ts;
    var $link;

    var $title;
    var $text;
}

class BlogFeed
{
    var $posts = array();

    function __construct($file_or_url)
    {
        $file_or_url = $this->resolveFile($file_or_url);
        if (!($x = simplexml_load_file($file_or_url)))
            return;

        foreach ($x->channel->item as $item)
        {
            $post = new BlogPost();
            $post->date  = (string) $item->pubDate;
            $post->ts    = strtotime($item->pubDate);
            $post->link  = (string) $item->link;
            $post->title = (string) $item->title;
            $post->text  = (string) $item->description;

            // Create summary as a shortened body and remove images, 
            // extraneous line breaks, etc.
            $post->summary = $this->summarizeText($post->text);

            $this->posts[] = $post;
        }
    }

    private function resolveFile($file_or_url) {
        if (!preg_match('|^https?:|', $file_or_url))
            $feed_uri = $_SERVER['DOCUMENT_ROOT'] .'/shared/xml/'. $file_or_url;
        else
            $feed_uri = $file_or_url;

        return $feed_uri;
    }

    private function summarizeText($summary) {
        $summary = strip_tags($summary);

        // Truncate summary line to 100 characters
        $max_len = 100;
        if (strlen($summary) > $max_len)
            $summary = substr($summary, 0, $max_len) . '...';

        return $summary;
    }
}

Solution 3

With 4 lines, I import a rss to an array.

$feed = implode(file('http://yourdomains.com/feed.rss'));
$xml = simplexml_load_string($feed);
$json = json_encode($xml);
$array = json_decode($json,TRUE);

For a more complex solution

$feed = new DOMDocument();
 $feed->load('file.rss');
 $json = array();
 $json['title'] = $feed->getElementsByTagName('channel')->item(0)->getElementsByTagName('title')->item(0)->firstChild->nodeValue;
 $json['description'] = $feed->getElementsByTagName('channel')->item(0)->getElementsByTagName('description')->item(0)->firstChild->nodeValue;
 $json['link'] = $feed->getElementsByTagName('channel')->item(0)->getElementsByTagName('link')->item(0)->firstChild->nodeValue;
 $items = $feed->getElementsByTagName('channel')->item(0)->getElementsByTagName('item');

 $json['item'] = array();
 $i = 0;

 foreach($items as $key => $item) {
 $title = $item->getElementsByTagName('title')->item(0)->firstChild->nodeValue;
 $description = $item->getElementsByTagName('description')->item(0)->firstChild->nodeValue;
 $pubDate = $item->getElementsByTagName('pubDate')->item(0)->firstChild->nodeValue;
 $guid = $item->getElementsByTagName('guid')->item(0)->firstChild->nodeValue;

 $json['item'][$key]['title'] = $title;
 $json['item'][$key]['description'] = $description;
 $json['item'][$key]['pubdate'] = $pubDate;
 $json['item'][$key]['guid'] = $guid; 
 }

echo json_encode($json);

Solution 4

I would like introduce simple script to parse RSS:

$i = 0; // counter
$url = "http://www.banki.ru/xml/news.rss"; // url to parse
$rss = simplexml_load_file($url); // XML parser

// RSS items loop

print '<h2><img style="vertical-align: middle;" src="'.$rss->channel->image->url.'" /> '.$rss->channel->title.'</h2>'; // channel title + img with src

foreach($rss->channel->item as $item) {
if ($i < 10) { // parse only 10 items
    print '<a href="'.$item->link.'">'.$item->title.'</a><br />';
}

$i++;
}

Solution 5

If feed isn't well-formed XML, you're supposed to reject it, no exceptions. You're entitled to call feed creator a bozo.

Otherwise you're paving way to mess that HTML ended up in.

View more solutions

Comments

[Helen Neely]

+1, you should not try to work around any XML that is not well-formed. We've had bad experiences with them, trust me, it was big pain :(

[artur]

Zend Feed framework.zend.com/manual/en/zend.feed.html

[Talvi Watia]

you have an end-tag with no start tag. ;)

[Brian Cline]

Well, I had one, but it was being eaten by SO's code formatter since it had no empty line above it. On a related note, you did not start your sentence with a capital letter. ;)

[Kevin Pastor]

However, programmers do not get to choose business partners and have to parse what they are given.

[duality_]

I don't like such "answers", giving links without any comments. Looks like you google it and link to a few top results. Especially since the asker has some RSS experience and needs a better parser.

[Tim]

Please change $feed_uri = $feed_or_url; to $feed_uri = $file_or_url; ... other than that, thank you for this code! It works great!

[András Szepesházi]

Note that while this solution is great, it'll only parse RSS feeds in it's current form. Atom feeds will not be parsed due to their different schema.

[ITS Alaska]

Note that eregi_replace is now deprecated and has been replaced with preg_replace as well as eregi with preg_match. Documentations can be found here and here respectively.

[yPhil]

What if you're building an universal RSS/Atom feed reader ? If any ill-formed xml file can "mess" your HTML, who is the Bozo ? ;) Be liberal in what you receive.

[vladkras]

I don't understand what is cookHtmlSummarySoup() for? whay not use strip_tags()?

[Brian Cline]

@ITSAlaska Thanks for the reminder. I think even back when I posted this in 2008 it was old code. I've updated it with preg_match accordingly.

[Brian Cline]

@vladkras Good question. Not sure where that wacky method name came from, looks like someone here edited it. I much prefer a built-in, so I've updated this to use strip_tags(). Thanks for the tip.

[samayo]

I just tried it. It does not give an array

[PJunior]

can u give me the rss feed that u are using?

[andrewk]

In case you're wondering. It looks like he's using a tumblr rss feed. Anytumblrsite.com/rss would give you the same output.

[Raptor]

In case somebody needs a little bit advice, Last RSS is the easiest among the three listed above. Only 1 file to "require", and can fetch the RSS within 5 lines, with a decent array output.

[Guidouil]

Used the 4 lines, did a great job :) but then I rewrote the 1st line : $feed = file_get_contents('http://yourdomains.com/feed.rss'); might be less intensive than file + implode

[Will Bowman]

cant say its "great" using gzinflate and base64_decode, typically disabled for security.

[Will Bowman]

one line, $feed = json_decode(json_encode(simplexml_load_file('news.google.com‌​/?output=rss')), true);

[Fluchtpunkt]

i really like the one-liner - was looking for something like that - what about error-handling?

[gadelat]

picoFeed github.com/fguillot/picoFeed

[noob]

I've used two of them and LastRss seems not good enough providing a fully functional helper and SimplePie is a bit too complicated. I would like to try some others but comments to those libs are better for people to understand, not just links.

[musicin3d]

Why on earth are we converting an object into an array???

[John T]

Clear and simple solution! Works nicely.

[Sagive]

it's a dead link for marketing porpuses.

[Srinivas08]

rather than using $xml = simplexml_load_string($feed), this works pretty simple, in printing the data too ...