Reading XML file in parts - php

Question

I am trying to read a XML file from the URL, with the help of XMLReader Iterators https://gist.github.com/hakre/5147685
$reader = new XMLReader();
$reader->open($filename);
$element = new XMLReaderNode($reader);
$it = new XMLElementIterator($reader, 'coupon');
$data = array();
$i = 0;
foreach($it as $index => $element) {
if( $i == 0 ) {
$xml = $element->asSimpleXML();
//print_r($xml->children());
foreach( $xml as $k=>$v ) {
$data[0][strtolower("{$k}")] = "{$v}";
}
}// End IF
}
print_r($data);
Its working fine with the small file, but its taking long time to read xml file from url.
Can i first download the file from url then READ it?
Is it the right way that i am doing?
Is there any other alternative?

Answer 1

If I understand your question right, it just takes long to download the large file all the time.
But you can just cache the file locally, by first download the XML from an http-URI and then store it to disk.
This is very useful when you develop your software because otherwise doing the remote-request all the time to fetch the XML is a needless overhead and I assume the data is not that fresh that it changes for each of your parsing tests and you would require those changes in the XML.
I suggest to do something along the lines from the answer of Download File to server from URL:
$filename = "http://someurl/file.xml";
$cachefile = "file.xml";
if (!is_readable($cachefile)
{
file_put_contents($cachefile, fopen($filename, 'r'));
}
$reader = new XMLReader();
$reader->open($cachefile);
This little example will create the $cachefile in case it does not exists. In case it does exists, it will not download again.
So this will only take once longer to load that file. You can also first download the XML file if it is really large with a HTTP client that supports resume (partial transfers) like the wget or the curl command-line utilities because if in case something goes wrong with the transfer, you don't have to download the whole file again.
You then just operate on your local copy. You wouldn't need to change your code then at all, just $filename would point to the local file instead.