Implementing a SOAP API with PHP ubuntu

instalar la extension soap para php:

In ubuntu to install php_soap on PHP7 use below commands. Reference

sudo apt-get install php7.0-soap

en mi caso que tengo instalado php7.2:
sudo apt-get install php7.2-soap

Crear una carpeta dentro de htdocs:

mkdir hello

Install the zend-soap library:

Dentro de la carpeta "hello" instalar via composer la libreria zend-soap (se creará los archivos composer.json y composer.lock)

composer require zendframework/zend-soap

Creating a SOAP Endpoint

The endpoint is the URL where your service can be accessed by a client application. To see the WSDL you add ?wsdl to the web service endpoint URL.

Let's create a simple hello world webservice.

Content of server.php:

  <?php

   require_once __DIR__ . '/vendor/autoload.php';

   class Hello
{
    /**
     * Say hello.
     *
     * @param string $firstName
     * @return string $greetings
     */
    public function sayHello($firstName)
    {
        return 'Hello ' . $firstName;
    }

}
 
   $serverUrl = "http://localhost/hello/server.php";
   $options = [
    'uri' => $serverUrl,
    ]; 
   $server = new Zend\Soap\Server(null, $options);

   if (isset($_GET['wsdl'])) {
     $soapAutoDiscover = new \Zend\Soap\AutoDiscover(new \Zend\Soap\Wsdl\ComplexTypeStrategy\ArrayOfTypeSequence());
     $soapAutoDiscover->setBindingStyle(array('style' => 'document'));
     $soapAutoDiscover->setOperationBodyStyle(array('use' => 'literal'));
     $soapAutoDiscover->setClass('Hello');
     $soapAutoDiscover->setUri($serverUrl);

     header("Content-Type: text/xml");
     echo $soapAutoDiscover->generate()->toXml();
}  else {
     $soap = new \Zend\Soap\Server($serverUrl . '?wsdl');
     $soap->setObject(new \Zend\Soap\Server\DocumentLiteralWrapper(new Hello()));
     $soap->handle();
   }

Open the browser to see the WSDL file: http://localhost/hello/server.php?wsdl

Creating a SOAP Client

Create a new file client.php.

File content:

   <?php

    require_once __DIR__ . '/vendor/autoload.php';

    $client = new Zend\Soap\Client('http://localhost/hello/server.php?wsdl');  
    $result = $client->sayHello(['firstName' => 'World']);

    echo $result->sayHelloResult;

The result (response) should look like this:

   Hello World

It is possible that your PHP Static Analysis Tool (e.g. phpstan) has a problem with calling $client->sayHello(...). The reason is that this method does not exist and is called internally via a magic method. To avoid this warning there is a simple trick. Instead, call the web service methods using call(method, params)-methode and simply pass the method name as a string. Note that the parameters must be passed in a double nested array.

$result = $client->call('sayHello', [['firstName' => 'World']]);

echo $result->sayHelloResult;

fuente:

https://dev.to/dopitz/implementing-a-soap-api-with-php-a3n

nota:
si despues de una primera ejecucion se quiere agregar nuevos metodos, o modificar el existente y que lo reconozca el client, se debe agregar tanto en el server como el client
la sgt linea (despues del require...) para que no lea la caché, sino no va a encontrar los nuevos metodos

ini_set('soap.wsdl_cache_enabled', '0');