将CURL用于SOAP是一种不好的做法吗？

Question

There is a piece of software in my company connecting periodically with some webservices via SOAP protocol using curl in PHP. From time to time this fails and the whole system is very unstable. I was a bit surprised seeing curl as a main tool talking to these webservices, because I thought there exist robust and mature high level libraries for most languages (including PHP and python) and curl is relatively low-level and doesn't provide any error handling. Am I right? What is the best solution for communication via SOAP? Is there some enterprise standard I can follow? Please help.

Answer 1

PHPs build in SOAP Client is already very robust and abstracts many of the commonly needed stuff:

$this->soapClient = new SoapClient($wsdl_url);
// What interface is available, which function can you call?
var_dump($this->soapClient->__getFunctions());

// Call
$result = $this->soapClient->someMethodExposedByTheApi();

// Soap Elements (Tags in the XML) are available as properties:
echo $result->someProperty;

// Nested Tags are available as object chain:
echo $result->someNestedTags->nestedTag;

I could not imagine how it can be any simpler ...

If you need to setup a SOAP Service, you may want to use Zend_Soap, a stand alone component in the Zend Framework, that automatically builds a webservice based on a wsdl. It also has a wrapper on top of PHP's SoapClient, but this is mainly used to converge naming and coding conventions to the Zend Framework and does not provide much additional functionality.

However: Curl is ok if you have very specific requierements. If it fails from time to time and your system is unstable, than it's not a problem of curl. It may be a misconfiguration of the service or system.

Basically the SoapClient builds an XML based on the Standard. If you build the XML for yourself (for whatever reason), curl is ok.