ChEBI Web Services - Making a PHP SOAP Client

Question

[support]

On the ChEBI Web Services page: https://www.ebi.ac.uk/chebi/webServices.do

They give two examples of SOAP Clients for retrieving data from ChEBI, one of them is written in Java, one of them written in Perl. Heres the Perl example:

#!/usr/bin/perl -w
# SOAP::Lite version 0.67
# Please note: ChEBI webservices uses document/literal binding

use SOAP::Lite + trace => qw(debug);
#use SOAP::Lite;

# Setup service
my $WSDL = 'http://www.ebi.ac.uk/webservices/chebi/2.0/webservice?wsdl';
my $nameSpace = 'http://www.ebi.ac.uk/webservices/chebi';
my $soap = SOAP::Lite
   -> uri($nameSpace)
   -> proxy($WSDL);

# Setup method and parameters
my $method = SOAP::Data->name('getCompleteEntity')
                   ->attr({xmlns => $nameSpace});
my @params = ( SOAP::Data->name(chebiId => 'CHEBI:15377'));

# Call method
my $som = $soap->call($method => @params);

# Retrieve for example all ChEBI identifiers for the ontology parents
@stuff = $som->valueof('//OntologyParents//chebiId');
print @stuff;

The language I know best is PHP, so I want to convert this example into PHP. I'm new to the whole SOAP thing, so I barely know where to start. Heres what I started with:

$WSDL = 'http://www.ebi.ac.uk/webservices/chebi/2.0/webservice?wsdl';
$nameSpace = 'http://www.ebi.ac.uk/webservices/chebi';

$options = array(
    'uri'=>$nameSpace,
    'trace'=>true,
    'encoding'=>'UTF-8',
    'exceptions'=>true,
  );

/* Initialize webservice with your WSDL */
$client = new SoapClient($WSDL,$options);

/* Set your parameters for the request */
$params = array(
  'chebiId' => 'CHEBI:15377',
);

/* Invoke webservice method with your parameters */
$response = $client->__soapCall("getCompleteEntity", array($params));

/* Print webservice response */
var_dump($response);

Heres the output of that: http://pastebin.com/g3w0wf6u

So the things I'm wondering are:

1.) What do I do with the namespace? In the perl example, they setup the service like this:

my $soap = SOAP::Lite
   -> uri($nameSpace)
   -> proxy($WSDL);

How do I use the namespace with PHP SoapClient? I added it as the 'uri' option when setting up the webservice, but I don't actually know what that means. And they setup the method like this:

# Setup method and parameters
my $method = SOAP::Data->name('getCompleteEntity')
                   ->attr({xmlns => $nameSpace});

I see I need to apply it to the methods also. How do I setup a new method with the namespace applied, as shown in the Perl example?

What does proxy and uri mean in the perl example?

Also how can I replicate this:

@stuff = $som->valueof('//OntologyParents//chebiId');

With the SoapClient?

Answer 1

[support]

It was actually very easy, heres the code for the PHP SOAP client I made:

http://www.ebi.ac.uk/webservices/chebi/2.0/webservice?wsdl';
  public $nameSpace = 'http://www.ebi.ac.uk/webservices/chebi';


  /* Initialize webservice with your WSDL */
  public $options;
  public $client;

  public function __construct() {

    $this->options = array(
      'uri'=>$this->nameSpace,
      'trace'=>true,
      'encoding'=>'UTF-8',
      'exceptions'=>true,
    );

    $this->client = new SoapClient($this->WSDL,$this->options);


  }

  //  --------------------- EXAMPLE OF FUNCTION WHICH USES ONE OF THE WEBSERVICE METHODS -------------------------  //

  public function getAllChildren($chebiId,$relationshipType = 'is a',$structure = false) {

    /* Set your parameters for the request */
    $params = array(
      'chebiId' => $chebiId,
      'relationshipType' => $relationshipType,
      'structureOnly' => $structure
    );

    $data = $this->callSOAP('getAllOntologyChildrenInPath',$params);

    return $data;

  }

  //  --------------------- SOAP SETUP FUNCTIONS -------------------------  //

  public function callSOAP($method,$params) {

    try
      {
        $response = $this->client->__soapCall($method,array($params),array('uri' => $this->nameSpace));

        $data = $response->return;

        if (isset($data->ListElement)) { $data = $data->ListElement; }

        $data = convertToArray($data);

        return $data;
      } 
      catch(SoapFault $ex){
          echo $ex->getMessage();
      }

  }

}

To use it, do something like this:

$chebi = new SOAP_Tools();

$params = array(
    'search' => 'biological role',
    'searchCategory' => 'ALL',
    'maximumResults' => 50,
   'stars' => 'ALL'
);

$data = $chebi->callSOAP('getLiteEntity',$params);

I threw in the convertToArray function because its a pain in the ass working with an array of objects that it returns by default, so I added that to convert the output into a pure array.