How to sort XML feed using PHP - php

Question

I am new this parsing xml feeds; so I have a piece of code that I have been working on that extracts the data from the xml file. Now I want be able to sort the array by the publish date pubdate. I have not found any examples that can anyone help me.
I used sort() which puts it in some random order.
$xml_headline_key = "*ARRAY*CATCHUP*PROGRAMMENAME";
$xml_link_key = "*ARRAY*CATCHUP*ITEMURL";
$xml_description_key = "*ARRAY*CATCHUP*SHORTSYNOPSIS";
$xml_publish_key = "*ARRAY*CATCHUP*ORIGINALAIRINGDATE";
$story_array = array();
$counter = 0;
class xml_story{
var $headline, $description, $link, $pubdate;
}
function contents($parser, $data){
global $current_tag, $xml_headline_key, $xml_link_key, $xml_description_key, $counter, $story_array, $xml_link_key, $xml_publish_key;
switch($current_tag){
case $xml_headline_key:
$story_array[$counter] = new xml_story();
$story_array[$counter]->headline = $data;
break;
case $xml_link_key:
$story_array[$counter]->link = $data;
break;
case $xml_description_key:
$story_array[$counter]->description = $data;
$counter++;
break;
case $xml_publish_key:
$story_array[$counter]->pubdate = $data;
break;
}
}
$corrie_counter = 0;
sort($story_array);
$dateformat = "D j M, g:ia";
for($x=0;$x<count($story_array);$x++){
if($story_array[$x]->headline == "Coronation Street"){
if($corrie_counter != 4){
echo "<li><span class=\"bold\">". date($dateformat, strtotime($story_array[$x]->pubdate)) . "</span>\n";
echo "\t<span class=\"text\">" . trunc($story_array[$x]->description,30, " ") . "</span>\n";
echo "\t";
$corrie_counter++;
}
}
}

Answer 1

You can use uasort, and inside sortByPubdate define the way the two pubdates should be compared.
uasort($story_array, 'sortByPubdate');
// Sort function
function sortByPubdate($a, $b) {
if ($a->pubdate == $b->pubdate) {
return 0;
}
return ($a->pubdate < $b->pubdate) ? -1 : 1;
}