最近工作的内容使用到了接口!
对于系统接口:
现下接触的有两种!

1、URL类型的接口

URL路由带参数式的接口!这个很好做!只要有过Web开发经验的人都能完成!
这种接口数据不够隐蔽性,可以直接在浏览其中看到,

如支付宝的交易请求URL。需要加一个MD5签名,和服务器端的再次向支付宝服务器发送验证!
虽然soap方式传递的数据隐蔽性很好!但为了数据安全,难免也需要进行数据签名。

2、SOAP类型的接口

无关编程语言、无关平台、扩展性很好

要实现一个SOAP 型的接口,有两种方式:一种有WSDL文件方式、一中无WSDL文件方式!
对于热爱研究型的人来说,使用第一种方式可以让你清楚的了解PHP是怎么创建了一个Web Service!
但第一种对于新手来说,创建一个XML格式的WSDL文件,是比较难的,这你的先了解熟悉什么是XML!
学会XML语法!
但对于一个急于解决问题的人来说!没有这么多的时间去熟悉!所以这是件烦恼的事!
不过不急,上面说了,还有一种无需WSDL文件的方式!而且,本讲解还提供了一个自动生成WSDL文件的类!

讲解前,先配置下PHP的soap环境支持:

找到php.ini文件
;extension=php_soap.dll

删除掉";" ,重启服务器

一、有WSDL文件方式
在这里先介绍标准的webservice。
那么如何创建wsdl呢?对于PHP来说这确实是件很不容易的事情,有人说用zend studio创建很方便,这是一种方法。但对于那些不喜欢用zend studio的人来说,会觉得创建一个web service还要安装zend studio,太强人所难了。
在这里介绍一个简单的方法,到网上下载SoapDiscovery.class.php类,里面有个公用方法:getWSDL,这个方法末尾是用的return,那么,你修改一下这个方法:
//return sprintf('%s%s%s%s%s%s', $headerWSDL, $portTypeWSDL, $bindingWSDL, $serviceWSDL, $messageWSDL, '</definitions>');
//生成wsdl文件,将上面的return注释
$fso = fopen($this->class_name . ".wsdl" , "w");
fwrite($fso, sprintf('%s%s%s%s%s%s', $headerWSDL, $portTypeWSDL, $bindingWSDL, $serviceWSDL, $messageWSDL, '</definitions>'));
现在生成wsdl的类有了,SoapDiscovery.class.php(源码在最末尾)。

再准备一个提供服务的Service.php类文件或者函数就可以创建wsdl了!

<?php
class Service {

    public function HelloWorld() {
        return "Hello";
    }

    public function Add($a, $b) {
        return $a + $b;
    }

}
?>

创建wsdl文件的creat_wsdl.php

<?php

include("Service.php");
include("SoapDiscovery.class.php");

$disco = new SoapDiscovery('Service', 'soap'); //第一个参数是类名(生成的wsdl文件就是以它来命名的),即Service类,第二个参数是服务的名字(这个可以随便写)。
$disco->getWSDL();

运行create_wsdl.php文件,此时会生成一个Service.wsdl的文件

再在Service.php文件中添加一些代码

<?php

class Service {

    public function HelloWorld() {
        return "Hello";
    }

    public function Add($a, $b) {
        return $a + $b;
    }

}

$server = new SoapServer('Service.wsdl', array('soap_version' => SOAP_1_2));
$server->setClass("Service"); //注册Service类的所有方法
$server->handle(); //处理请求

?>

创建webservice客户端程序,测试webservice是否有效,文件名是:client.php
将以下内容拷贝进去:

<?php

 ini_set('soap.wsdl_cache_enabled', "0"); //关闭wsdl缓存

  $soap = new SoapClient('http://localhost/Dragon/soap/Service.php?wsdl');
 echo $soap->Add(28, 2);
  echo $soap->__soapCall('Add',array(28,2))//或这样调用

OK!测试通过!

二、无WSDL文件方式

服务器端

<?php
class Service
{
  public function HelloWorld()
   {
      return  "Hello";
   }
  public  function Add($a,$b)
   {
      return $a+$b;
   }
}
$server=new SoapServer(null,array('uri' => "abcd"));
$server->setClass("Service");
$server->handle();

客户端

<?php
  try {
  $soap = new SoapClient(null, array(
  "location" => "http://localhost/Dragon/soap/Service.php",
  "uri" => "abcd", //资源描述符服务器和客户端必须对应
  "style" => SOAP_RPC,
  "use" => SOAP_ENCODED
  ));

  echo $soap->Add(12, 2);
  } catch (Exction $e) {
  echo print_r($e->getMessage(), true);
  }

三.出现的问题。

1.在方法中对属性的赋值在其他方法中不起作用。
比如在客户端调用服务端某个方法对某个属性赋值。
在其他方法里就不能用。但在 __construct 方法中对属性的赋值是可以个在其他方法中使用的。

2. 提示 Client] looks like we got no XML document错误。
服务器端文件在<?php ?> 标签前后都不要有任何数据包括空格,空行。

3. Warning: SoapClient::SoapClient(): I/O warning : failed to load external entity
原因如下:PHP程序作为 SOAP客户端 采用 WSDL 模式访问远端服务器的时候,PHP是通过调用 libcurl 实现的。至少在 PHP5.2.X 是这样的。如果采用 non-WSDL 模式,就不需要 libcurl。除了 了ibcurl以外,至少还关联的库包括:libidn,ibgcc,libiconv,libintl,openssl

现在,你已经解决你了系统接口的问题了!剩下的空余时间,就有必要去了解什么是SOAP、http协议、XML了!

SoapDiscovery.class.php 文件

<?php

/**
 * Copyright (c) 2005, Braulio Jos?Solano Rojas
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *     Redistributions of source code must retain the above copyright notice, this list of
 *     conditions and the following disclaimer.
 *     Redistributions in binary form must reproduce the above copyright notice, this list of
 *     conditions and the following disclaimer in the documentation and/or other materials
 *     provided with the distribution.
 *     Neither the name of the Solsoft de Costa Rica S.A. nor the names of its contributors may
 *     be used to endorse or promote products derived from this software without specific
 *     prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * @version $Id$
 * @copyright 2005
 */

/**
 * SoapDiscovery Class that provides Web Service Definition Language (WSDL).
 *
 * @package SoapDiscovery
 * @author Braulio Jos?Solano Rojas
 * @copyright Copyright (c) 2005 Braulio Jos?Solano Rojas
 * @version $Id$
 * @access public
 * */
class SoapDiscovery {

    private $class_name = '';
    private $service_name = '';

    /**
     * SoapDiscovery::__construct() SoapDiscovery class Constructor.
     *
     * @param string $class_name
     * @param string $service_name
     * */
    public function __construct($class_name = '', $service_name = '') {
        $this->class_name = $class_name;
        $this->service_name = $service_name;
    }

    /**
     * SoapDiscovery::getWSDL() Returns the WSDL of a class if the class is instantiable.
     *
     * @return string
     * */
    public function getWSDL() {
        if (empty($this->service_name)) {
            throw new Exception('No service name.');
        }
        $headerWSDL = "<?xml version=\"1.0\" ?>\n";
        $headerWSDL.= "<definitions name=\"$this->service_name\" targetNamespace=\"urn:$this->service_name\" xmlns:wsdl=\"http://schemas.xmlsoap.org/wsdl/\" xmlns:soap=\"http://schemas.xmlsoap.org/wsdl/soap/\" xmlns:tns=\"urn:$this->service_name\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\" xmlns=\"http://schemas.xmlsoap.org/wsdl/\">\n";
        $headerWSDL.= "<types xmlns=\"http://schemas.xmlsoap.org/wsdl/\" />\n";

        if (empty($this->class_name)) {
            throw new Exception('No class name.');
        }

        $class = new ReflectionClass($this->class_name);

        if (!$class->isInstantiable()) {
            throw new Exception('Class is not instantiable.');
        }

        $methods = $class->getMethods();

        $portTypeWSDL = '<portType name="' . $this->service_name . 'Port">';
        $bindingWSDL = '<binding name="' . $this->service_name . 'Binding" type="tns:' . $this->service_name . "Port\">\n<soap:binding style=\"rpc\" transport=\"http://schemas.xmlsoap.org/soap/http\" />\n";
        $serviceWSDL = '<service name="' . $this->service_name . "\">\n<documentation />\n<port name=\"" . $this->service_name . 'Port" binding="tns:' . $this->service_name . "Binding\"><soap:address location=\"http://" . $_SERVER['SERVER_NAME'] . ':' . $_SERVER['SERVER_PORT'] . $_SERVER['PHP_SELF'] . "\" />\n</port>\n</service>\n";
        $messageWSDL = '';
        foreach ($methods as $method) {
            if ($method->isPublic() && !$method->isConstructor()) {
                $portTypeWSDL.= '<operation name="' . $method->getName() . "\">\n" . '<input message="tns:' . $method->getName() . "Request\" />\n<output message=\"tns:" . $method->getName() . "Response\" />\n</operation>\n";
                $bindingWSDL.= '<operation name="' . $method->getName() . "\">\n" . '<soap:operation soapAction="urn:' . $this->service_name . '#' . $this->class_name . '#' . $method->getName() . "\" />\n<input><soap:body use=\"encoded\" namespace=\"urn:$this->service_name\" encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\" />\n</input>\n<output>\n<soap:body use=\"encoded\" namespace=\"urn:$this->service_name\" encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\" />\n</output>\n</operation>\n";
                $messageWSDL.= '<message name="' . $method->getName() . "Request\">\n";
                $parameters = $method->getParameters();
                foreach ($parameters as $parameter) {
                    $messageWSDL.= '<part name="' . $parameter->getName() . "\" type=\"xsd:string\" />\n";
                }
                $messageWSDL.= "</message>\n";
                $messageWSDL.= '<message name="' . $method->getName() . "Response\">\n";
                $messageWSDL.= '<part name="' . $method->getName() . "\" type=\"xsd:string\" />\n";
                $messageWSDL.= "</message>\n";
            }
        }
        $portTypeWSDL.= "</portType>\n";
        $bindingWSDL.= "</binding>\n";
        //return sprintf('%s%s%s%s%s%s', $headerWSDL, $portTypeWSDL, $bindingWSDL, $serviceWSDL, $messageWSDL, '</definitions>');
        //生成wsdl文件,将上面的return注释
        $fso = fopen($this->class_name . ".wsdl", "w");
        fwrite($fso, sprintf('%s%s%s%s%s%s', $headerWSDL, $portTypeWSDL, $bindingWSDL, $serviceWSDL, $messageWSDL, '</definitions>'));
    }

    /**
     * SoapDiscovery::getDiscovery() Returns discovery of WSDL.
     *
     * @return string
     * */
    public function getDiscovery() {
        return "<?xml version=\"1.0\" ?>\n<disco:discovery xmlns:disco=\"http://schemas.xmlsoap.org/disco/\" xmlns:scl=\"http://schemas.xmlsoap.org/disco/scl/\">\n<scl:contractRef ref=\"http://" . $_SERVER['SERVER_NAME'] . ':' . $_SERVER['SERVER_PORT'] . $_SERVER['PHP_SELF'] . "?wsdl\" />\n</disco:discovery>";
    }

}

?>

=================================================================================

修正版:
根据YII 的CWsdlGenerator改变而来,

增加了接口参数的类型识别;

使用前需使用IDE对方法名进行注释,方可自动生成有效的WSDL文件。(具体原因可查看代码processMethod方法中的115行)

调用方法:

<?php
include(dirname(__FILE__) . './Service.class.php');
include(dirname(__FILE__) . './SoapDiscovery.class.php');
$disco = new SoapDiscovery();
$disco->getWSDL('service', 'http://www.xxx.com/service.php');
?>

<?php

/**
 * CWsdlGenerator class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CWsdlGenerator generates the WSDL for a given service class.
 *
 * The WSDL generation is based on the doc comments found in the service class file.
 * In particular, it recognizes the '@soap' tag in the comment and extracts
 * API method and type definitions.
 *
 * In a service class, a remote invokable method must be a public method with a doc
 * comment block containing the '@soap' tag. In the doc comment, the type and name
 * of every input parameter and the type of the return value should be declared using
 * the standard phpdoc format.
 *
 * CWsdlGenerator recognizes the following primitive types (case-sensitive) in
 * the parameter and return type declarations:
 * <ul>
 * <li>str/string: maps to xsd:string;</li>
 * <li>int/integer: maps to xsd:int;</li>
 * <li>float/double: maps to xsd:float;</li>
 * <li>bool/boolean: maps to xsd:boolean;</li>
 * <li>date: maps to xsd:date;</li>
 * <li>time: maps to xsd:time;</li>
 * <li>datetime: maps to xsd:dateTime;</li>
 * <li>array: maps to xsd:string;</li>
 * <li>object: maps to xsd:struct;</li>
 * <li>mixed: maps to xsd:anyType.</li>
 * </ul>
 *
 * If a type is not a primitive type, it is considered as a class type, and
 * CWsdlGenerator will look for its property declarations. Only public properties
 * are considered, and they each must be associated with a doc comment block containg
 * the '@soap' tag. The doc comment block should declare the type of the property.
 *
 * CWsdlGenerator recognizes the array type with the following format:
 * <pre>
 * typeName[]: maps to tns:typeNameArray
 * </pre>
 *
 * The following is an example declaring a remote invokable method:
 * <pre>
 * / **
 *   * A foo method.
 *   * @param string name of something
 *   * @param string value of something
 *   * @return string[] some array
 *   * @soap
 *   * /
 * public function foo($name,$value) {...}
 * </pre>
 *
 * And the following is an example declaring a class with remote accessible properties:
 * <pre>
 * class Foo {
 *     / **
 *       * @var string name of foo
 *       * @soap
 *       * /
 *     public $name;
 *     / **
 *       * @var Member[] members of foo
 *       * @soap
 *       * /
 *     public $members;
 * }
 * </pre>
 * In the above, the 'members' property is an array of 'Member' objects. Since 'Member' is not
 * a primitive type, CWsdlGenerator will look further to find the definition of 'Member'.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CWsdlGenerator.php 2799 2011-01-01 19:31:13Z qiang.xue $
 * @package system.web.services
 * @since 1.0
 */
class SoapDiscovery {

    /**
     * @var string the namespace to be used in the generated WSDL.
     * If not set, it defaults to the name of the class that WSDL is generated upon.
     */
    public $namespace;

    /**
     * @var string the name of the generated WSDL.
     * If not set, it defaults to "urn:{$className}wsdl".
     */
    public $serviceName;
    private $_operations;
    private $_types;
    private $_messages;

    /**
     * Generates the WSDL for the given class.
     * @param string $className class name
     * @param string $serviceUrl Web service URL
     * @param string $encoding encoding of the WSDL. Defaults to 'UTF-8'.
     * @return string the generated WSDL
     */
    public function getWSDL($className, $serviceUrl, $encoding = 'UTF-8') {
        $this->_operations = array();
        $this->_types = array();
        $this->_messages = array();
        if ($this->serviceName === null)
            $this->serviceName = $className;
        if ($this->namespace === null)
            $this->namespace = "urn:{$className}wsdl";

        $reflection = new ReflectionClass($className);
        foreach ($reflection->getMethods() as $method) {
            if ($method->isPublic())
                $this->processMethod($method);
        }

        //return $this->buildDOM($serviceUrl, $encoding)->saveXML();

        $fso = fopen($this->serviceName . ".wsdl", "w");
        fwrite($fso, $this->buildDOM($serviceUrl, $encoding)->saveXML());
    }

    /*
     * @param ReflectionMethod $method method
     */

    private function processMethod($method) {
        $comment = $method->getDocComment();

        if (strpos($comment, '@soap') === false)
            return;

        $methodName = $method->getName();
        $comment = preg_replace('/^\s*\**(\s*?$|\s*)/m', '', $comment);
        $params = $method->getParameters();
        $message = array();
        $n = preg_match_all('/^@param\s+([\w\.]+(\[\s*\])?)\s*?(.*)$/im', $comment, $matches);

        if ($n > count($params))
            $n = count($params);
        for ($i = 0; $i < $n; ++$i)
            $message[$params[$i]->getName()] = array($this->processType($matches[1][$i]), trim($matches[3][$i])); // name => type, doc

        $this->_messages[$methodName . 'Request'] = $message;

        if (preg_match('/^@return\s+([\w\.]+(\[\s*\])?)\s*?(.*)$/im', $comment, $matches))
            $return = array($this->processType($matches[1]), trim($matches[2])); // type, doc
        else
            $return = null;

        $this->_messages[$methodName . 'Response'] = array('return' => $return);

        if (preg_match('/^\/\*+\s*([^@]*?)\n@/s', $comment, $matches))
            $doc = trim($matches[1]);
        else
            $doc = '';
        $this->_operations[$methodName] = $doc;
    }

    /*
     * @param string $type PHP variable type
     */

    private function processType($type) {
        static $typeMap = array(
    'string' => 'xsd:string',
    'str' => 'xsd:string',
    'int' => 'xsd:int',
    'integer' => 'xsd:integer',
    'float' => 'xsd:float',
    'double' => 'xsd:float',
    'bool' => 'xsd:boolean',
    'boolean' => 'xsd:boolean',
    'date' => 'xsd:date',
    'time' => 'xsd:time',
    'datetime' => 'xsd:dateTime',
    'array' => 'soap-enc:Array',
    'object' => 'xsd:struct',
    'mixed' => 'xsd:anyType',
        );
        if (isset($typeMap[$type]))
            return $typeMap[$type];
        else if (isset($this->_types[$type]))
            return is_array($this->_types[$type]) ? 'tns:' . $type : $this->_types[$type];
        else if (($pos = strpos($type, '[]')) !== false) { // if it is an array
            $type = substr($type, 0, $pos);
            if (isset($typeMap[$type]))
                $this->_types[$type . '[]'] = 'xsd:' . $type . 'Array';
            else {
                $this->_types[$type . '[]'] = 'tns:' . $type . 'Array';
                $this->processType($type);
            }
            return $this->_types[$type . '[]'];
        }
    }

    /*
     * @param string $serviceUrl Web service URL
     * @param string $encoding encoding of the WSDL. Defaults to 'UTF-8'.
     */

    private function buildDOM($serviceUrl, $encoding) {
        $xml = "<?xml version=\"1.0\" encoding=\"$encoding\"?>
<definitions name=\"{$this->serviceName}\" targetNamespace=\"{$this->namespace}\"
     xmlns=\"http://schemas.xmlsoap.org/wsdl/\"
     xmlns:tns=\"{$this->namespace}\"
     xmlns:soap=\"http://schemas.xmlsoap.org/wsdl/soap/\"
     xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"
     xmlns:wsdl=\"http://schemas.xmlsoap.org/wsdl/\"
     xmlns:soap-enc=\"http://schemas.xmlsoap.org/soap/encoding/\"></definitions>";

        $dom = new DOMDocument();
        $dom->loadXml($xml);
        $this->addTypes($dom);

        $this->addMessages($dom);
        $this->addPortTypes($dom);
        $this->addBindings($dom);
        $this->addService($dom, $serviceUrl);

        return $dom;
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     */

    private function addTypes($dom) {
        if ($this->_types === array())
            return;
        $types = $dom->createElement('wsdl:types');
        $schema = $dom->createElement('xsd:schema');
        $schema->setAttribute('targetNamespace', $this->namespace);
        foreach ($this->_types as $phpType => $xmlType) {
            if (is_string($xmlType) && strrpos($xmlType, 'Array') !== strlen($xmlType) - 5)
                continue;  // simple type
            $complexType = $dom->createElement('xsd:complexType');
            if (is_string($xmlType)) {
                if (($pos = strpos($xmlType, 'tns:')) !== false)
                    $complexType->setAttribute('name', substr($xmlType, 4));
                else
                    $complexType->setAttribute('name', $xmlType);
                $complexContent = $dom->createElement('xsd:complexContent');
                $restriction = $dom->createElement('xsd:restriction');
                $restriction->setAttribute('base', 'soap-enc:Array');
                $attribute = $dom->createElement('xsd:attribute');
                $attribute->setAttribute('ref', 'soap-enc:arrayType');
                $attribute->setAttribute('wsdl:arrayType', substr($xmlType, 0, strlen($xmlType) - 5) . '[]');
                $restriction->appendChild($attribute);
                $complexContent->appendChild($restriction);
                $complexType->appendChild($complexContent);
            }
            else if (is_array($xmlType)) {
                $complexType->setAttribute('name', $phpType);
                $all = $dom->createElement('xsd:all');
                foreach ($xmlType as $name => $type) {
                    $element = $dom->createElement('xsd:element');
                    $element->setAttribute('name', $name);
                    $element->setAttribute('type', $type[0]);
                    $all->appendChild($element);
                }
                $complexType->appendChild($all);
            }
            $schema->appendChild($complexType);
            $types->appendChild($schema);
        }

        $dom->documentElement->appendChild($types);
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     */

    private function addMessages($dom) {
        foreach ($this->_messages as $name => $message) {
            $element = $dom->createElement('wsdl:message');
            $element->setAttribute('name', $name);
            foreach ($this->_messages[$name] as $partName => $part) {
                if (is_array($part)) {
                    $partElement = $dom->createElement('wsdl:part');
                    $partElement->setAttribute('name', $partName);
                    $partElement->setAttribute('type', $part[0]);
                    $element->appendChild($partElement);
                }
            }
            $dom->documentElement->appendChild($element);
        }
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     */

    private function addPortTypes($dom) {
        $portType = $dom->createElement('wsdl:portType');
        $portType->setAttribute('name', $this->serviceName . 'PortType');
        $dom->documentElement->appendChild($portType);
        foreach ($this->_operations as $name => $doc)
            $portType->appendChild($this->createPortElement($dom, $name, $doc));
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     * @param string $name method name
     * @param string $doc doc
     */

    private function createPortElement($dom, $name, $doc) {
        $operation = $dom->createElement('wsdl:operation');
        $operation->setAttribute('name', $name);

        $input = $dom->createElement('wsdl:input');
        $input->setAttribute('message', 'tns:' . $name . 'Request');
        $output = $dom->createElement('wsdl:output');
        $output->setAttribute('message', 'tns:' . $name . 'Response');

        $operation->appendChild($dom->createElement('wsdl:documentation', $doc));
        $operation->appendChild($input);
        $operation->appendChild($output);

        return $operation;
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     */

    private function addBindings($dom) {
        $binding = $dom->createElement('wsdl:binding');
        $binding->setAttribute('name', $this->serviceName . 'Binding');
        $binding->setAttribute('type', 'tns:' . $this->serviceName . 'PortType');

        $soapBinding = $dom->createElement('soap:binding');
        $soapBinding->setAttribute('style', 'rpc');
        $soapBinding->setAttribute('transport', 'http://schemas.xmlsoap.org/soap/http');
        $binding->appendChild($soapBinding);

        $dom->documentElement->appendChild($binding);

        foreach ($this->_operations as $name => $doc)
            $binding->appendChild($this->createOperationElement($dom, $name));
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     * @param string $name method name
     */

    private function createOperationElement($dom, $name) {
        $operation = $dom->createElement('wsdl:operation');
        $operation->setAttribute('name', $name);
        $soapOperation = $dom->createElement('soap:operation');
        $soapOperation->setAttribute('soapAction', $this->namespace . '#' . $name);
        $soapOperation->setAttribute('style', 'rpc');

        $input = $dom->createElement('wsdl:input');
        $output = $dom->createElement('wsdl:output');

        $soapBody = $dom->createElement('soap:body');
        $soapBody->setAttribute('use', 'encoded');
        $soapBody->setAttribute('namespace', $this->namespace);
        $soapBody->setAttribute('encodingStyle', 'http://schemas.xmlsoap.org/soap/encoding/');
        $input->appendChild($soapBody);
        $output->appendChild(clone $soapBody);

        $operation->appendChild($soapOperation);
        $operation->appendChild($input);
        $operation->appendChild($output);

        return $operation;
    }

    /*
     * @param DOMDocument $dom Represents an entire HTML or XML document; serves as the root of the document tree
     * @param string $serviceUrl Web service URL
     */

    private function addService($dom, $serviceUrl) {
        $service = $dom->createElement('wsdl:service');
        $service->setAttribute('name', $this->serviceName . 'Service');

        $port = $dom->createElement('wsdl:port');
        $port->setAttribute('name', $this->serviceName . 'Port');
        $port->setAttribute('binding', 'tns:' . $this->serviceName . 'Binding');

        $soapAddress = $dom->createElement('soap:address');
        $soapAddress->setAttribute('location', $serviceUrl);
        $port->appendChild($soapAddress);
        $service->appendChild($port);
        $dom->documentElement->appendChild($service);
    }

}