如何使用php解析外部XML文件（从POST返回）？

Question

I have a simple code written (based on some tutorials found around the internet) to parse and display an XML file. However, I only know how to reference an XML file stored on my server and I would like to be able to use an XML file that is being returned to me from a POST.

Right now my code looks like this:

if( ! $xml = simplexml_load_file('test.xml') )
{
    echo 'unable to load XML file';
}
else
{
    foreach( $xml as $event)
    {
        echo 'Title: ';
        echo "<a href=\"$event->url\">$event->title</a><br />";
        echo 'Description: '.$event->info.'<br />';
        echo '<br />';
    }
} 

Is there some way I can replace the simpleXML_load_file function with one that will allow me to point to the POST URL that returns the XML file?

Answer 1

Use simplexml_load_string instead of loadfile:

 simplexml_load_string($_POST['a']);

If you get the url to the file in the POST you can propably use the simplexml_load_file function with the url, but if that doesn't work you can use the file_get_contents in combination with the simplexml_load_string:

//say $_POST['a'] == 'http://example.com/test.xml';
simplexml_load_file($_POST['a']); // <-- propably works
simplexml_load_string(file_get_contents($_POST['a'])); //<-- defenitly works (propaly what happens internally)

also getting contents of external files could be prohibited by running PHP in safe mode.

Answer 2

If you are receiving a file that's been uploaded by the user, you can find it (the file) looking at the content of the $_FILES superglobal variable -- and you can read more about files uploads here (for instance, don't forget to call move_uploaded_file if you don't want the file to be deleted at the end of the request) .

Then, you can work with this file the same way you already do with not-uploaded files.

If you are receiving an XML string, you can use simplexml_load_string on it.

And if you are only receiving the URL to a remote XML content, you have to :

• download the file to your server
• and, then, parse its content.

This can be done using simplexml_load_file , passing the URL as a parameter, if your server is properly configured (ie if allow_url_fopen is enabled).

Else, the download will have to be done using curl -- see curl_exec for a very basic example, and curl_setopt for the options you can use (you'll especially want to use CURLOPT_RETURNTRANSFER , to get the XML data as a string you can pass to simplexml_load_string ).

Answer 3

From http://www.developershome.com/wap/wapUpload/wap_upload.asp?page=php4 :

If you do not want to save the uploaded file directly but to process it, the PHP functions file_get_contents() and fread() can help you. The file_get_contents() function returns a string that contains all data of the uploaded file:

if (is_uploaded_file($_FILES['myFile']['tmp_name']))
  $fileData = file_get_contents($_FILES['myFile']['tmp_name']);

That will give you a handle on the raw text within that file. From there you will need to parse through the XML. Hope that helps!

Answer 4

Check out simplexml_load_string . You can then use cURL to do the post and fetch the result. An example:

<?php
$xml = simplexml_load_string($string_fetched_with_curl);
?>