Caveat - some of this code is very old, and may include stuff which is deprecated or no longer required by the latest version of Collect. If more knowledgeable folks know better, please correct any misunderstandings in the content below. All I can say for definite is that this approach does work with the latest Collect version.
Also, the loose typing inherent in this kind of PHP will be alien to any Java people, but please don't criticise, because that's what the OP asked for!
To accept Collect submissions, you first need to set your server hostname and submission URL in Collect's Preferences - you'll need to set the Server URL to point to your own server. The Submission Path is "/submission/" by default, but again, it can be changed in the Collect prefences.
At the submission URL, you need to provide an OpenRosa-compliant set of responses to Collect's submission request.
The submission request has two stages - a HEAD request first, then a POST request - the HEAD request expects a Location header response which gives Collect a submission URL for the POST request.
The POST request posts the XML file of completed form data, plus any extra asset files such as photos or images of signature captures etc.
So my form processor looks something like this (NB this is for illustration only and untested, and by no means optimal or elegant!).
<?php
//With default Collect Submission path setting, this script would be located at https://your.server/submission/index.php
//this is where all the uploaded files will eventually be stored.
$datapath='/path/to/your/datafiles/';
//Set a variable to tell us whether an XML file has successfully been uploaded later:
$xmlfile=false;
//we need to process POST and HEAD requests separately, and cater for GET just in case
$method=strtolower($_SERVER['REQUEST_METHOD']);
//Issue these response headers to both HEAD and POST requests:
header("Content-Type: text/xml; charset=utf-8");
header("Content-Language: en");
header("X-OpenRosa-Version: 1.0");
header("X-OpenRosa-Accept-Content-Length: 10000000");//limit upload to 10Mb - probably too high for most realistic scenarios!
//Now process POST and HEAD requests differently
if ($method=='post') {
//we should have at least one POSTED file
if (isset($_FILES)) {
//we need to move all the POSTed files from the tmp upload folder, as with any file POST, then respond with a Success code and message.
foreach($_FILES as $file) {
$filename=$file['name'];
$ok=move_uploaded_file($file['tmp_name'],$datapath.$filename);
//There should only be one XML file, which is the completed form. Any other files are assets, whose file names will be included in the form data.
if ($file['type']=="text/xml") $xmlfile=$file['name'];
}
header("HTTP/1.1 202 Accepted");
echo '<?xml version="1.0" encoding="UTF-8" ?>';
echo '<OpenRosaResponse xmlns="http://openrosa.org/http/response" items="1">';
echo '<message nature="submit_success">Form submitted successfully</message>';
echo '</OpenRosaResponse>';
}
else {
/* If $_FILES is not set in the POST, that means we have no XML file of the completed form, so we need to return an error. This should really be a 400, but
in my original implementation circa 2012, Collect didn't interpret a 400 response correctly, and only a 403 response would produce a human-readable
error message in Collect. */
header("HTTP/1.1 403 Forbidden");
echo '<?xml version="1.0" encoding="UTF-8" ?>';
echo '<OpenRosaResponse xmlns="http://openrosa.org/http/response" items="1">';
echo '<message nature="submit_success">Submission unsuccessful - no data files were received.</message>';
echo '</OpenRosaResponse>';
}
}
if ($method=='head' || $method=='get') {
//This is the initial HEAD request from Collect, so we need to return a Location header telling Collect where to POST the completed form.
//We also provide this response to GET requests to give us browser testing options.
header("Location: $_SERVER[SCRIPT_URI]");//this script -
header("HTTP/1.1 204 No Content");//that's all, no actual content in the response.
}
if ($xmlfile!==false){
//now process the contents of $path.$xmlfile however you want to!
require 'my_form_processor_script.php';
}
?>
Comments and corrections welcome!
Nik