PHP Web Services with NuSOAP

Introduction

NuSOAP is a group of PHP classes that allow developers to create and consume SOAP web services. It does not require any special PHP extensions.This document describes how to obtain and install NuSOAP, then provides some samples to illustrate the capabilities of NuSOAP. It is by no means an exhaustive description of NuSOAP, but it is hopefully enough to get any PHP coder started. Programming with NuSOAP follows this up with more complex samples.

What are Web Services

The term Web services describes a standardized way of integrating Web-based applications using the XML, SOAP, WSDL and UDDI open standards over an Internet protocol backbone. XML is used to tag the data, SOAP is used to transfer the data, WSDL is used for describing the services available and UDDI is used for listing what services are available. Used primarily as a means for businesses to communicate with each other and with clients, Web services allow organizations to communicate data without intimate knowledge of each other's IT systems behind the firewall.

Web Services Protocol Stack

The Web Services protocol stack consists of three key XML-based technologies: SOAP (Simple Object Access Protocol), WSDL (Web Service Description Language), and UDDI (Universal Description, Discovery and Integration).
UDDI: This layer is responsible for centralizing services into a common registry, and providing easy publish/find functionality. Currently, service discovery is handled via the UDDI. The UDDI specification can help to solve making it possible to discover the right services from the millions currently online. Learn more about UDDI here.
WSDL: This layer is responsible for describing the public interface to a specific Web service, which is an XML-based language that describes the various functions that a Web service is capable of. Currently, service description is handled via the WSDL. You do not need to learn all the nitty-gritty details because there are tools that generate WSDL for you. You can get one here.

SOAP: This layer is responsible for encoding messages in a common XML format so that messages can be understood at either end. Currently, this includes XML-RPC and SOAP. For example, the client program bundles up two values to be added into a SOAP message, which is sent to the Web service by sending it as the body of an HTTP POST request. The server unpacks the SOAP request that the application can understand and executes Add operation. Next, the server packages up that result of summation as response into another SOAP message, which it sends back to the client program in response to its HTTP request. The client program unpacks the SOAP message to obtain the results of the summation. So, SOAP= XML + HTTP.

Creating Nusoap

Download latest version of nusoap.php from http://sourceforge.net/projects/nusoap/

Here I am going to create a server which will take UserID as request and fetch User's details with respect to the UserID

• Creating the user's table
  

CREATE TABLE `tbl_user` (
`user_id` int(11) NOT NULL auto_increment,
`user_name` varchar(30) NOT NULL default '',
`password` varchar(70) NOT NULL default '',
`first_name` varchar(100) NOT NULL default '',
`last_name` varchar(100) NOT NULL default '',
`email_id` varchar(100) NOT NULL default '',
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

• Creating a php page to fetch record from table "tbl_user"

# Save this code a userclass.php

class Users {

function DBConnection()
{
mysql_pconnect ('HostName', 'UserName', 'PassWord') ;
mysql_select_db ('DataBaseName');
}

function getUserDetails($userid){

$this->DBConnection();
$Query = "SELECT * FROM tbl_user where user_id = $userid";
$result = mysql_query($Query) or die(" Your ERROR CODE ");

if(!$result) {
die(" Your ERROr CODE ");
}
$cnt = 0;
$UserResultArray= array();
while ($UserResult = mysql_fetch_assoc($result))
{

// Result Array
$UserResultArray[$cnt] = array(
'UserID' => $UserResult["user_id"],
'UserName' => $UserResult["user_name"],
'FirstName' => $UserResult["first_name"],
'LastName' => $UserResult["last_name"],
'EmailID' => $UserResult["email_id"]);


$cnt = $cnt + 1;
}


return $UserResultArray;
}


}

// End of userclass.php

• Creating Nusoap Server code

// Save this code as users.php


// Downloaded Nusoap file
require_once("nusoap.php");
// Including the created php function file
require_once("userclass.php");
// Name space name
$ns="urn:UserDetails_wsdl";
$server = new soap_server();
// Configure WSDL
$server->configureWSDL('UserDetails_wsdl', 'urn:UserDetails_wsdl');
$server->wsdl->schemaTargetNamespace=$ns;


// Creating Complex type for out put (only for single record)
$server->wsdl->addComplexType('UserDetailsRow',
'complexType','struct', 'all', '',
array( 'UserID' => array('name' => 'UserID', 'type' => 'xsd:int'),
'UserName' => array('name' => 'UserName','type' => 'xsd:string'),
'FirstName' => array('name' => 'FirstName','type' => 'xsd:string'),
'LastName' => array('name' => 'LastName','type' => 'xsd:string'),
'EmailID' => array('name' => 'EmailID','type' => 'xsd:string')
));

// Complex type for multiple record out put.
$server->wsdl->addComplexType('UserDetailsRows','complexType',
'array','','SOAP-ENC:Array',
array(),array(array('ref'=>'SOAP-ENC:arrayType','wsdl:arrayType'=>'tns:UserDetailsRow[]')),
'tns:UserDetailsRow');

// Registering getUserDetails function for WSDL generation
$server->register('getUserDetails', // method name
array('' => 'xsd:void'), // input parameters
array('return' => 'tns:UserDetailsRows'), // output parameters
'urn:UserDetails_wsdl', // namespace
'urn:UserDetails_wsdl#getUserDetails', // soapaction
'rpc', // style
'encoded', // use
'Fetching User details' // documentation
);

// Main function (Registered function)
function getUserDetails($userid)
{
$userClass = new Users; // Object from userclass.php
return $userClass->getUserDetails($userid);
}

//=============
// Output return
//=============
$HTTP_RAW_POST_DATA = isset($GLOBALS['HTTP_RAW_POST_DATA']) ? $GLOBALS['HTTP_RAW_POST_DATA'] : '';
$HTTP_RAW_POST_DATA = file_get_contents("php://input");
$server->service($HTTP_RAW_POST_DATA);
exit();

// End of users.php

You can access your WSDL file now using http://localhost/users.php . You will be getting below out put

• Creating Client for Nusoap

// Save this code as getUserDetails.php

require_once('nusoap.php');
$soapclient = new soapclient('http://localhost/users.php');
$soapclient->debug_flag=true;
$err = $soapclient->getError();
$UserID = $_REQUEST["UserID"];
$param = array("UserID"=>$UserID);
$result=$soapclient->call("getUserDetails",$param);
header("Content-Type: text/xml\r\n");
echo $soapclient->responseData;

// End of getUserDetails.php

Now we can access our client using
'http://localhost/getUserDetails.php?UserID=1'
Verify the below output of newly created Nusoap XML webservice . Make sure that you are passing UserID as argument in the query string .


Now you can make your own webservices with different format .

Enjoy !!!!!!

Vineesh.