Implementing a SOAP API with PHP - Generating WSDL
According to google
WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint.
Having a wsdl definition is one of the requirements for using other programming langurages to interact with the end point.
We need to create a wsdl for the BookService. There are a few php packages which can generate the wsdl, I found this PHP-Generate-WSDL-from-PHP-classes-code
It is quite simple to use as shown in the example code.
<?php
require_once __DIR__ . "/vendor/autoload.php";
$class = "Bookcatalog\BookService";
$serviceURI = "http://localhost:8091";
$wsdlGenerator = new PHP2WSDL\PHPClass2WSDL($class, $serviceURI);
$wsdlGenerator->generateWSDL(true);
// Dump as string
$wsdlXML = $wsdlGenerator->dump();
// Or save as file
$wsdlXML = $wsdlGenerator->save('book.wsdl');
The wsdl file can now be specified in the server constructor as follows
<?php
ini_set("soap.wsdl_cache_enabled", "0");
require_once __DIR__ . "/vendor/autoload.php";
$class = "Bookcatalog\BookService";
$wsdl = "book.wsdl";
// initialize SOAP Server
$server=new SoapServer($wsdl,[
'uri'=>"http://localhost:8091/server.php"
]);
$server->setClass($class);
// start handling requests
$server->handle();
To be able to generate a fully functional wsdl file however, the BookService class has to be fully annotated before the file is generated.
Annotations
- @soap : On all methods that have to be exposed.
- @param : On input paramters.
- @return : On return types.
- @var : On fields in an input or output class definition.
The BookService.php is now defined as follows
<?php
namespace Bookcatalog;
class BookService
{
public function __construct(){
$this->_books = [
['id'=>'5409' , 'name'=>'Programming for Dummies','year'=>2011,'price'=>'12.09'],
['id'=>'2311','name'=>'Project Management 101','year'=>2017,'price'=>'20.09'],
['id'=>'98777','name'=>'Rust Development','year'=>2020,'price'=>'32.09'],
];
}
/**
* @soap
* @param integer $id
* @return integer
*/
public function bookYear($id){
$bookYear = "";
foreach($this->_books as $bk){
if($bk['id']==$id)
return $bk['year']; // book found
}
return $bookYear; // book not found
}
/**
* @soap
* @param Bookcatalog\Book $book
* @return string
*/
public function bookDetails($book){
foreach($this->_books as $bk){
if($bk['name']==$book->name)
return json_encode($bk);
}
return ""; // book not found
}
}
Because an input parameter $book is been used, a definition is needed for it. Also the definition for the class has to be fully qualified.
Book.php is defined as follows
<?php
namespace Bookcatalog;
class Book
{
/**
* @var string
*/
public $name;
/**
* @var string
*/
public $year;
}