How to limit the content of XML feeds I save in an array?

Question

Is there any way to still make use of all the feeds but instead of loading all the 25 posts of every feed (<entry></entry> or <item></item>), to get the first 10 posts of every feed.

$feeds = array('',''); //a looot of inputs

$entries = array();
foreach ($feeds as $feed) {

    $xml = simplexml_load_file($feed);
    $xml->registerXPathNamespace('f', 'http://www.w3.org/2005/Atom');

    $entries = array_merge($entries, $xml->xpath('/f:feed/f:entry | /rss/channel//item'));

}

@madflow Does it have any purpose if I still load all the feeds first? `$xml = simplexml_load_file($feed);` — EnexoOnoma, Oct 02 '11 at 19:13
Right - sorry - My point being : This must have been already answered. Still an interesting question though ;) — madflow, Oct 02 '11 at 19:14
What are you actually trying to speed up? It seems your approach will be retrieving each feed sequentially, rather than in parallel. — salathe, Oct 02 '11 at 19:29
How about getting the feeds, storing them in an array and then slice the array http://php.net/manual/en/function.array-slice.php — Mob, Oct 02 '11 at 19:32
@Mob I do not know... Isn't a double procedure/performance to load the entire feeds in an array and then slice it? Will this help in output? I updated my question. — EnexoOnoma, Oct 02 '11 at 19:41

score 0 · Accepted Answer · answered Oct 02 '11 at 21:08

0

Try this:

$entries = array();
foreach ($feeds as $feed) {

    $xml = simplexml_load_file($feed);
    $xml->registerXPathNamespace('f', 'http://www.w3.org/2005/Atom');

    $entries = array_merge($entries, $xml->xpath('/f:feed/f:entry[position() <= 10] | /rss/channel//item[position() <= 10]') );
}

This uses position().

answered Oct 02 '11 at 21:08

Decent Dabbler

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Even by this the entire documents are loaded, but the size of the array is reduced right? Does this speed things up? – EnexoOnoma Oct 02 '11 at 21:42
@mtopia: somewhat I think, depending on how many feeds you are reading. But if you only want to partially load XML files (feeds) I think you may want to look into [`XMLReader`](http://php.net/manual/en/book.xmlreader.php). Although I must admit: I haven't been able to figure out how it works exactly. I believe it *does* however allow you to do what you want though: reading an XML stream element by element, so to speak, and not read the whole document at once. – Decent Dabbler Oct 02 '11 at 22:19
I tried it in another app I was building but the speed of it was awful. – EnexoOnoma Oct 02 '11 at 22:26
@mtopia: really? Hmmm... was that application fetching the xml from some other server by any chance (as I suppose your current script is doing as well?)? It's just a guess, but I would think reading a stream partially, element by element, from another server, could indeed cause it to slow down. `XMLReader` is probably more useful on local filesystem streams than on external streams. But to be honest: that's just an educated guess. Don't take my word for it. – Decent Dabbler Oct 03 '11 at 06:46
No it was reading from a local huge file. I read some benchmarks about it so I tried it. I tested many codes but nothing beated simpleXML. – EnexoOnoma Oct 03 '11 at 13:50

How to limit the content of XML feeds I save in an array?

1 Answers1