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QTransfer
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QTransfer is a collection of classes which can be used for exchanging
data in xml format between servers language independently.
You can use it i.e. for ASP or SAAS software application based on php.
The request scheme (xsd) can be delivered to a customer who gets an API
like interface for producing valid xml based requests.
The sample setup demonstrates how to
- setup xsd schemes,
- prepare request xml data streams which request specific application data
- validate incoming responses
Sample Setup Request XML:
$request = new Transfer_XmlRequest("Test","Module","index");
$request->setSchema("request");
$request->render(); // renders the domdocument to string
if($request->isValid()) {
$requestXML = $request->getXml(); // pure XML
} else {
echo "invalid request";
exit;
}
Q: What does this piece of code?
A: It builds a xml and checks its integrity. This xml is laterly send to a server
which processes the incoming xml structure.
sample xml output:
<?xml version="1.0" encoding="UTF-8"?>
<transfer>
<head>
<context>Test</context>
<module>Module</module>
<action>index</action>
<checksum>--40 chars long checksum string here--</checksum>
<format>xml</format>
<version>0.1.1</version>
</head>
<body>
</body>
</transfer>
Q: Why do I have to validate the request?
A: Suppose you want to deliver some data to a customer from your server. The customer
only has to know how to send a xml stream to a specific adress and that he will receive
a xmlml response. He must not know anything about server language etc.. He only
has to know how to setup his request for being able to receive xml data.
The validation of the xml, which is send by the customer, is helps to
avoid failures. If a xml validation fails then he knows that something went
wrong. The major advantage of such a validation is? A customer's server and the serving host
must not be speak the same language. So it is language independent.
You can write PHP and your customer writes JSP, does not matter.
Sample customer request sends the xml to the hosted service front-controller etc.:
$c = Transfer_Curl::getInstance()
->doPostXML("http://www.query4u.de/test/index.php",$requestXML);
The variable $c gets the response xml. Now, the response can be validated
against a reponse schema which is parametrized like the request.
$response = new Transfer_XmlResponse("Test","Module","index");
$response->setSchema("response");
$response->setOutput($c);
$response->render();
if($response->isValid()) {
header("content-type: text/xml");
echo $response->getXml();
} else {
echo "invalid response";
}
Now you have the requested results in xml format which can be easily
processed by any system.
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