Status report during form process - php

Question

I created a little script that imports wordpress posts from an xml file:
if(isset($_POST['wiki_import_posted'])) {
// Get uploaded file
$file = file_get_contents($_FILES['xml']['tmp_name']);
$file = str_replace('&', '&', $file);
// Get and parse XML
$data = new SimpleXMLElement( $file , LIBXML_NOCDATA);
foreach($data->RECORD as $key => $item) {
// Build post array
$post = array(
'post_title' => $item->title,
........
);
// Insert new post
$id = wp_insert_post( $post );
}
}
The problem is that my xml file is really big, and when i submit the form, the browser just hangs for a couple of minutes.
Is it possible to display some messages during the import, like displaying a dot after every item is imported?

Answer 1

Unfortunately, no, not easily. Especially if you're building this on top of the WP framework you'll find it not worth your while at all. When you're interacting with a PHP script you are sending a request and awaiting a response. However long it takes that PHP script to finish processing and start sending output is how long it usually takes the client to start seeing a response.
There are a few things to consider if what you want is for output to start showing as soon as possible (i.e. as soon as the first echo or output statement is reached).
Turn off output buffering so that output begins sending immediately.
Output whatever you want inside the loop that would indicate to you the progress you wish to be know about.
Note that if you're doing this with an AJAX request content may not be ready immediately to transport to the DOM via your XMLHttpRequest object. Also note that some browsers do their own buffering before content can be ready for the user to display (like IE for example).
Some suggestions you may want to look into to speed up your script, however:
Why are you doing str_replace('&','&',$file) on a large file? You realize that has cost with no benefit, right? You've acomplished nothing and if you meant you want to replace the HTML entity & then you probably have some of your logic very wrong. Encoding is something you want to let the XML parser handle.
You can use curl_multi instead of file_get_contents to do multiple HTTP requests concurrently to save time if you are transferring a lot of files. It will be much faster since it's none-blocking I/O.
You should use DOMDocument instead of SimpleXML and a DOMXPath query can get you your array much faster than what you're currently doing. It's a much nicer interface than SimpleXML and I always recommend it above SimpleXML since in most cases SimpleXML makes things incredibly difficult to do and for no good reason. Don't let the name fool you.