Re-order XML results based on XML data [duplicate] - php

Question

This question already has answers here:
PHP sorting issue with simpleXML
(3 answers)
Closed 9 years ago.
We are fetching data from a remote server via their API. Unfortunately, their API does not order the returned data by date.
I am trying, without much success, to figure out how to re-organize the data so that it is ordered by the next_bookable_date. We are using PHP and SimpleXMLElement to parse the data and create a string which is then inserted into a webpage. But the current result is in the same order as data appears in the returned XML.
The basic XML results are below. There is much more data, that I stripped out to save space.
SimpleXMLElement Object
(
[request] => GET search.xml?start_date=2013-05-03&end_date=2013-05-17
[error] => OK
[total_tour_count] => 4
[tour] => Array
(
[0] => SimpleXMLElement Object
(
[next_bookable_date] => 2013-05-13
[tour_name] => Thailand Tour
)
[1] => SimpleXMLElement Object
(
[next_bookable_date] => 2013-05-12
[tour_name] => Bali Tour
)
[2] => SimpleXMLElement Object
(
[next_bookable_date] => 2013-05-05
[tour_name] => Hawaii Tour
)
[3] => SimpleXMLElement Object
(
[next_bookable_date] => 2013-05-06
[tour_name] => Bhutan Tour
)
)
)
The PHP code we are using to generate the html string (again stripped of a bit of html code to save space):
foreach($result->tour as $tour) {
$tourname = $tour->tour_name;
$tourdate = $tour->next_bookable_date;
// create string for dpt-soon
$dpt_soon_list .= "<li> some html using the above values </li>\n";
}
Is there a way to re-order the XML data once we receive it from the remote server? Or is there a way to reorder the PHP output when running the foreach?

Answer 1

You can use usort() to sort multidimensional arrays or objects. I wrote this bit of code to explain how to use it with SimpleXML:
<?php
// Load the XML file
$xml = simplexml_load_file("xml.xml");
// Get all children into an array
$Tours = (array)$xml->children();
$Tours = $Tours["tour"];
// Call usort on the array
usort($Tours, "sorttours");
// Output results
echo "<pre>".print_r($Tours, true)."</pre>";
// The function that specifies when an entry is larger, equal or smaller than another
function sorttours($a, $b) {
// Parse strings into a date for comparison
$Date1 = strtotime($a->next_bookable_date);
$Date2 = strtotime($b->next_bookable_date);
// If equal, return 0
if ($Date1 == $Date2) {
return 0;
}
// If Date1 is larger, return 1, otherwise -1
return ($Date1 > $Date2) ? 1 : -1;
}
?>
This example assumes that the XML looks somewhat like this:
<?xml version="1.0"?>
<tours>
<tour>
<next_bookable_date>2013-05-13</next_bookable_date>
<tour_name>Thailand Tour</tour_name>
</tour>
<tour>
<next_bookable_date>2013-05-12</next_bookable_date>
<tour_name>Bali Tour</tour_name>
</tour>
<tour>
<next_bookable_date>2013-05-05</next_bookable_date>
<tour_name>Hawaii Tour</tour_name>
</tour>
<tour>
<next_bookable_date>2013-05-06</next_bookable_date>
<tour_name>Bhutan Tour</tour_name>
</tour>
</tours>
If that is not the case, then you need to rewrite the sorttours function to use e.g. attributes to determine the order.