| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> |
| <head> |
| |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> |
| <title>XML-RPC and XML-RPC Server Classes : CodeIgniter User Guide</title> |
| |
| <style type='text/css' media='all'>@import url('../userguide.css');</style> |
| <link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> |
| |
| <script type="text/javascript" src="../nav/nav.js"></script> |
| <script type="text/javascript" src="../nav/prototype.lite.js"></script> |
| <script type="text/javascript" src="../nav/moo.fx.js"></script> |
| <script type="text/javascript" src="../nav/user_guide_menu.js"></script> |
| |
| <meta http-equiv='expires' content='-1' /> |
| <meta http-equiv= 'pragma' content='no-cache' /> |
| <meta name='robots' content='all' /> |
| <meta name='author' content='ExpressionEngine Dev Team' /> |
| <meta name='description' content='CodeIgniter User Guide' /> |
| |
| </head> |
| <body> |
| |
| <!-- START NAVIGATION --> |
| <div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> |
| <div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> |
| <div id="masthead"> |
| <table cellpadding="0" cellspacing="0" border="0" style="width:100%"> |
| <tr> |
| <td><h1>CodeIgniter User Guide Version 1.7.2</h1></td> |
| <td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> |
| </tr> |
| </table> |
| </div> |
| <!-- END NAVIGATION --> |
| |
| |
| <!-- START BREADCRUMB --> |
| <table cellpadding="0" cellspacing="0" border="0" style="width:100%"> |
| <tr> |
| <td id="breadcrumb"> |
| <a href="http://codeigniter.com/">CodeIgniter Home</a> › |
| <a href="../index.html">User Guide Home</a> › |
| XML-RPC and XML-RPC Server Classes |
| </td> |
| <td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> |
| </tr> |
| </table> |
| <!-- END BREADCRUMB --> |
| |
| <br clear="all" /> |
| |
| |
| <!-- START CONTENT --> |
| <div id="content"> |
| |
| |
| <h1>XML-RPC and XML-RPC Server Classes</h1> |
| |
| |
| <p>CodeIgniter's XML-RPC classes permit you to send requests to another server, or set up |
| your own XML-RPC server to receive requests.</p> |
| |
| |
| <h2>What is XML-RPC?</h2> |
| |
| <p>Quite simply it is a way for two computers to communicate over the internet using XML. |
| One computer, which we will call the <dfn>client</dfn>, sends an XML-RPC <strong>request</strong> to |
| another computer, which we will call the <dfn>server</dfn>. Once the server receives and processes the request it |
| will send back a <strong>response</strong> to the client.</p> |
| |
| <p>For example, using the MetaWeblog API, an XML-RPC Client (usually a desktop publishing tool) will |
| send a request to an XML-RPC Server running on your site. This request might be a new weblog entry |
| being sent for publication, or it could be a request for an existing entry for editing. |
| |
| When the XML-RPC Server receives this request it will examine it to determine which class/method should be called to process the request. |
| Once processed, the server will then send back a response message.</p> |
| |
| <p>For detailed specifications, you can visit the <a href="http://www.xmlrpc.com/">XML-RPC</a> site.</p> |
| |
| <h2>Initializing the Class</h2> |
| |
| <p>Like most other classes in CodeIgniter, the XML-RPC and XML-RPCS classes are initialized in your controller using the <dfn>$this->load->library</dfn> function:</p> |
| |
| <p>To load the XML-RPC class you will use:</p> |
| <code>$this->load->library('xmlrpc');</code> |
| <p>Once loaded, the xml-rpc library object will be available using: <dfn>$this->xmlrpc</dfn></p> |
| |
| <p>To load the XML-RPC Server class you will use:</p> |
| <code> |
| $this->load->library('xmlrpc');<br /> |
| $this->load->library('xmlrpcs'); |
| </code> |
| <p>Once loaded, the xml-rpcs library object will be available using: <dfn>$this->xmlrpcs</dfn></p> |
| |
| <p class="important"><strong>Note:</strong> When using the XML-RPC Server class you must load BOTH the XML-RPC class and the XML-RPC Server class.</p> |
| |
| |
| |
| <h2>Sending XML-RPC Requests</h2> |
| |
| <p>To send a request to an XML-RPC server you must specify the following information:</p> |
| |
| <ul> |
| <li>The URL of the server</li> |
| <li>The method on the server you wish to call</li> |
| <li>The <em>request</em> data (explained below).</li> |
| </ul> |
| |
| <p>Here is a basic example that sends a simple Weblogs.com ping to the <a href="http://pingomatic.com/">Ping-o-Matic</a></p> |
| |
| |
| <code>$this->load->library('xmlrpc');<br /> |
| <br /> |
| $this->xmlrpc->server('http://rpc.pingomatic.com/', 80);<br /> |
| $this->xmlrpc->method('weblogUpdates.ping');<br /> |
| |
| <br /> |
| $request = array('My Photoblog', 'http://www.my-site.com/photoblog/');<br /> |
| $this->xmlrpc->request($request);<br /> |
| <br /> |
| if ( ! $this->xmlrpc->send_request())<br /> |
| {<br /> |
| echo $this->xmlrpc->display_error();<br /> |
| }</code> |
| |
| <h3>Explanation</h3> |
| |
| <p>The above code initializes the XML-RPC class, sets the server URL and method to be called (weblogUpdates.ping). The |
| request (in this case, the title and URL of your site) is placed into an array for transportation, and |
| compiled using the request() function. |
| Lastly, the full request is sent. If the <dfn>send_request()</dfn> method returns false we will display the error message |
| sent back from the XML-RPC Server.</p> |
| |
| <h2>Anatomy of a Request</h2> |
| |
| <p>An XML-RPC <dfn>request</dfn> is simply the data you are sending to the XML-RPC server. Each piece of data in a request |
| is referred to as a <dfn>request parameter</dfn>. The above example has two parameters: |
| The URL and title of your site. When the XML-RPC server receives your request, it will look for parameters it requires.</p> |
| |
| <p>Request parameters must be placed into an array for transportation, and each parameter can be one |
| of seven data types (strings, numbers, dates, etc.). If your parameters are something other than strings |
| you will have to include the data type in the request array.</p> |
| |
| <p>Here is an example of a simple array with three parameters:</p> |
| |
| <code>$request = array('John', 'Doe', 'www.some-site.com');<br /> |
| $this->xmlrpc->request($request);</code> |
| |
| <p>If you use data types other than strings, or if you have several different data types, you will place |
| each parameter into its own array, with the data type in the second position:</p> |
| |
| <code> |
| $request = array (<br /> |
| array('John', 'string'),<br /> |
| array('Doe', 'string'),<br /> |
| array(FALSE, 'boolean'),<br /> |
| array(12345, 'int')<br /> |
| ); |
| <br /> |
| $this->xmlrpc->request($request);</code> |
| |
| The <a href="#datatypes">Data Types</a> section below has a full list of data types. |
| |
| |
| |
| <h2>Creating an XML-RPC Server</h2> |
| |
| <p>An XML-RPC Server acts as a traffic cop of sorts, waiting for incoming requests and redirecting them to the |
| appropriate functions for processing.</p> |
| |
| <p>To create your own XML-RPC server involves initializing the XML-RPC Server class in your controller where you expect the incoming |
| request to appear, then setting up an array with mapping instructions so that incoming requests can be sent to the appropriate |
| class and method for processing.</p> |
| |
| <p>Here is an example to illustrate:</p> |
| |
| <code> |
| $this->load->library('xmlrpc');<br /> |
| $this->load->library('xmlrpcs');<br /> |
| <br /> |
| $config['functions']['<var>new_post</var>'] = array('function' => '<dfn>My_blog.new_entry</dfn>'),<br /> |
| $config['functions']['<var>update_post</var>'] = array('function' => '<dfn>My_blog.update_entry</dfn>');<br /> |
| $config['object'] = $this;<br /> |
| <br /> |
| $this->xmlrpcs->initialize($config);<br /> |
| $this->xmlrpcs->serve();</code> |
| |
| <p>The above example contains an array specifying two method requests that the Server allows. |
| The allowed methods are on the left side of the array. When either of those are received, they will be mapped to the class and method on the right.</p> |
| |
| <p>The '<var>object</var>' key is a special key that you pass an instantiated class object with, which is necessary when the method you are mapping to is not |
| part of the CodeIgniter super object.</p> |
| |
| <p>In other words, if an XML-RPC Client sends a request for the <var>new_post</var> method, your |
| server will load the <dfn>My_blog</dfn> class and call the <dfn>new_entry</dfn> function. |
| If the request is for the <var>update_post</var> method, your |
| server will load the <dfn>My_blog</dfn> class and call the <dfn>update_entry</dfn> function.</p> |
| |
| <p>The function names in the above example are arbitrary. You'll decide what they should be called on your server, |
| or if you are using standardized APIs, like the Blogger or MetaWeblog API, you'll use their function names.</p> |
| |
| <h2>Processing Server Requests</h2> |
| |
| <p>When the XML-RPC Server receives a request and loads the class/method for processing, it will pass |
| an object to that method containing the data sent by the client.</p> |
| |
| <p>Using the above example, if the <var>new_post</var> method is requested, the server will expect a class |
| to exist with this prototype:</p> |
| |
| <code>class <kbd>My_blog</kbd> extends Controller {<br /> |
| <br /> |
| function <kbd>new_post</kbd>(<var>$request</var>)<br /> |
| {<br /> |
| <br /> |
| }<br /> |
| } |
| </code> |
| |
| <p>The <var>$request</var> variable is an object compiled by the Server, which contains the data sent by the XML-RPC Client. |
| Using this object you will have access to the <em>request parameters</em> enabling you to process the request. When |
| you are done you will send a <dfn>Response</dfn> back to the Client.</p> |
| |
| <p>Below is a real-world example, using the Blogger API. One of the methods in the Blogger API is <dfn>getUserInfo()</dfn>. |
| Using this method, an XML-RPC Client can send the Server a username and password, in return the Server sends |
| back information about that particular user (nickname, user ID, email address, etc.). Here is how the processing |
| function might look:</p> |
| |
| |
| <code>class <kbd>My_blog</kbd> extends Controller {<br /> |
| <br /> |
| function <kbd>getUserInfo</kbd>(<var>$request</var>)<br /> |
| {<br /> |
| |
| $username = 'smitty';<br /> |
| $password = 'secretsmittypass';<br /><br /> |
| |
| $this->load->library('xmlrpc');<br /> |
| <br /> |
| $parameters = $request->output_parameters();<br /> |
| <br /> |
| if ($parameters['1'] != $username AND $parameters['2'] != $password)<br /> |
| {<br /> |
| return $this->xmlrpc->send_error_message('100', 'Invalid Access');<br /> |
| }<br /> |
| <br /> |
| $response = array(array('nickname' => array('Smitty','string'),<br /> |
| 'userid' => array('99','string'),<br /> |
| 'url' => array('http://yoursite.com','string'),<br /> |
| 'email' => array('jsmith@yoursite.com','string'),<br /> |
| 'lastname' => array('Smith','string'),<br /> |
| 'firstname' => array('John','string')<br /> |
| ),<br /> |
| 'struct');<br /> |
| <br /> |
| return $this->xmlrpc->send_response($response);<br /> |
| }<br /> |
| } |
| </code> |
| |
| <h3>Notes:</h3> |
| <p>The <dfn>output_parameters()</dfn> function retrieves an indexed array corresponding to the request parameters sent by the client. |
| In the above example, the output parameters will be the username and password.</p> |
| |
| <p>If the username and password sent by the client were not valid, and error message is returned using <dfn>send_error_message()</dfn>.</p> |
| |
| <p>If the operation was successful, the client will be sent back a response array containing the user's info.</p> |
| |
| |
| <h2>Formatting a Response</h2> |
| |
| <p>Similar to <em>Requests</em>, <em>Responses</em> must be formatted as an array. However, unlike requests, a response is an array |
| <strong>that contains a single item</strong>. This item can be an array with several additional arrays, but there |
| can be only one primary array index. In other words, the basic prototype is this:</p> |
| |
| <code>$response = array('Response data', 'array');</code> |
| |
| <p>Responses, however, usually contain multiple pieces of information. In order to accomplish this we must put the response into its own |
| array so that the primary array continues to contain a single piece of data. Here's an example showing how this might be accomplished:</p> |
| |
| <code> |
| $response = array (<br /> |
| array(<br /> |
| 'first_name' => array('John', 'string'),<br /> |
| 'last_name' => array('Doe', 'string'),<br /> |
| 'member_id' => array(123435, 'int'),<br /> |
| 'todo_list' => array(array('clean house', 'call mom', 'water plants'), 'array'),<br /> |
| ),<br /> |
| 'struct'<br /> |
| ); |
| </code> |
| |
| <p class="important">Notice that the above array is formatted as a <dfn>struct</dfn>. This is the most common data type for responses.</p> |
| |
| <p>As with Requests, a response can be one of the seven data types listed in the <a href="#datatypes">Data Types</a> section.</p> |
| |
| |
| <h2>Sending an Error Response</h2> |
| |
| <p>If you need to send the client an error response you will use the following:</p> |
| |
| <code>return $this->xmlrpc->send_error_message('123', 'Requested data not available');</code> |
| |
| <p>The first parameter is the error number while the second parameter is the error message.</p> |
| |
| |
| |
| |
| |
| |
| <h2>Creating Your Own Client and Server</h2> |
| |
| <p>To help you understand everything we've covered thus far, let's create a couple controllers that act as |
| XML-RPC Client and Server. You'll use the Client to send a request to the Server and receive a response.</p> |
| |
| <h3>The Client</h3> |
| |
| <p>Using a text editor, create a controller called <dfn>xmlrpc_client.php</dfn>. |
| In it, place this code and save it to your <samp>applications/controllers/</samp> folder:</p> |
| |
| <textarea class="textarea" style="width:100%" cols="50" rows="32"><?php |
| |
| class Xmlrpc_client extends Controller { |
| |
| function index() |
| { |
| $this->load->helper('url'); |
| $server_url = site_url('xmlrpc_server'); |
| |
| $this->load->library('xmlrpc'); |
| |
| $this->xmlrpc->server($server_url, 80); |
| $this->xmlrpc->method('Greetings'); |
| |
| $request = array('How is it going?'); |
| $this->xmlrpc->request($request); |
| |
| if ( ! $this->xmlrpc->send_request()) |
| { |
| echo $this->xmlrpc->display_error(); |
| } |
| else |
| { |
| echo '<pre>'; |
| print_r($this->xmlrpc->display_response()); |
| echo '</pre>'; |
| } |
| } |
| } |
| ?></textarea> |
| |
| <p>Note: In the above code we are using a "url helper". You can find more information in the <a href="../general/helpers.html">Helpers Functions</a> page.</p> |
| |
| <h3>The Server</h3> |
| |
| <p>Using a text editor, create a controller called <dfn>xmlrpc_server.php</dfn>. |
| In it, place this code and save it to your <samp>applications/controllers/</samp> folder:</p> |
| |
| <textarea class="textarea" style="width:100%" cols="50" rows="30"><?php |
| |
| class Xmlrpc_server extends Controller { |
| |
| function index() |
| { |
| $this->load->library('xmlrpc'); |
| $this->load->library('xmlrpcs'); |
| |
| $config['functions']['Greetings'] = array('function' => 'Xmlrpc_server.process'); |
| |
| $this->xmlrpcs->initialize($config); |
| $this->xmlrpcs->serve(); |
| } |
| |
| |
| function process($request) |
| { |
| $parameters = $request->output_parameters(); |
| |
| $response = array( |
| array( |
| 'you_said' => $parameters['0'], |
| 'i_respond' => 'Not bad at all.'), |
| 'struct'); |
| |
| return $this->xmlrpc->send_response($response); |
| } |
| } |
| ?></textarea> |
| |
| <h3>Try it!</h3> |
| |
| <p>Now visit the your site using a URL similar to this:</p> |
| <code>example.com/index.php/<var>xmlrpc_client</var>/</code> |
| |
| <p>You should now see the message you sent to the server, and its response back to you.</p> |
| |
| <p>The client you created sends a message ("How's is going?") to the server, along with a request for the "Greetings" method. |
| The Server receives the request and maps it to the "process" function, where a response is sent back.</p> |
| |
| <h2>Using Associative Arrays In a Request Parameter</h2> |
| |
| <p>If you wish to use an associative array in your method parameters you will need to use a struct datatype:</p> |
| |
| <code>$request = array(<br /> |
| array(<br /> |
| // Param 0<br /> |
| array(<br /> |
| 'name'=>'John'<br /> |
| ),<br /> |
| 'struct'<br /> |
| ),<br /> |
| array(<br /> |
| // Param 1<br /> |
| array(<br /> |
| 'size'=>'large',<br /> |
| 'shape'=>'round'<br /> |
| ),<br /> |
| 'struct'<br /> |
| )<br /> |
| );<br /> |
| $this->xmlrpc->request($request);</code> |
| |
| <p>You can retrieve the associative array when processing the request in the Server.</p> |
| |
| <code>$parameters = $request->output_parameters();<br /> |
| $name = $parameters['0']['name'];<br /> |
| $size = $parameters['1']['size'];<br /> |
| $size = $parameters['1']['shape']; </code> |
| |
| <h1>XML-RPC Function Reference</h1> |
| |
| <h2>$this->xmlrpc->server()</h2> |
| <p>Sets the URL and port number of the server to which a request is to be sent:</p> |
| <code>$this->xmlrpc->server('http://www.sometimes.com/pings.php', 80);</code> |
| |
| <h2>$this->xmlrpc->timeout()</h2> |
| <p>Set a time out period (in seconds) after which the request will be canceled:</p> |
| <code>$this->xmlrpc->timeout(6);</code> |
| |
| <h2>$this->xmlrpc->method()</h2> |
| <p>Sets the method that will be requested from the XML-RPC server:</p> |
| <code>$this->xmlrpc->method('<var>method</var>');</code> |
| |
| <p>Where <var>method</var> is the name of the method.</p> |
| |
| <h2>$this->xmlrpc->request()</h2> |
| <p>Takes an array of data and builds request to be sent to XML-RPC server:</p> |
| <code>$request = array(array('My Photoblog', 'string'), 'http://www.yoursite.com/photoblog/');<br /> |
| $this->xmlrpc->request($request);</code> |
| |
| <h2>$this->xmlrpc->send_request()</h2> |
| <p>The request sending function. Returns boolean TRUE or FALSE based on success for failure, enabling it to be used conditionally.</p> |
| |
| <h2>$this->xmlrpc->set_debug(TRUE);</h2> |
| <p>Enables debugging, which will display a variety of information and error data helpful during development.</p> |
| |
| |
| <h2>$this->xmlrpc->display_error()</h2> |
| <p>Returns an error message as a string if your request failed for some reason.</p> |
| <code>echo $this->xmlrpc->display_error();</code> |
| |
| <h2>$this->xmlrpc->display_response()</h2> |
| <p>Returns the response from the remote server once request is received. The response will typically be an associative array.</p> |
| <code>$this->xmlrpc->display_response();</code> |
| |
| <h2>$this->xmlrpc->send_error_message()</h2> |
| <p>This function lets you send an error message from your server to the client. First parameter is the error number while the second parameter |
| is the error message.</p> |
| <code>return $this->xmlrpc->send_error_message('123', 'Requested data not available');</code> |
| |
| <h2>$this->xmlrpc->send_response()</h2> |
| <p>Lets you send the response from your server to the client. An array of valid data values must be sent with this method.</p> |
| <code>$response = array(<br /> |
| array(<br /> |
| 'flerror' => array(FALSE, 'boolean'),<br /> |
| 'message' => "Thanks for the ping!")<br /> |
| )<br /> |
| 'struct');<br /> |
| return $this->xmlrpc->send_response($response);</code> |
| |
| |
| <a name="datatypes"></a> |
| <h2>Data Types</h2> |
| |
| <p>According to the <a href="http://www.xmlrpc.com/spec">XML-RPC spec</a> there are seven types |
| of values that you can send via XML-RPC:</p> |
| |
| <ul> |
| <li><em>int</em> or <em>i4</em></li> |
| <li><em>boolean</em></li> |
| <li><em>string</em></li> |
| <li><em>double</em></li> |
| <li><em>dateTime.iso8601</em></li> |
| <li><em>base64</em></li> |
| <li><em>struct</em> (contains array of values)</li> |
| <li><em>array</em> (contains array of values)</li> |
| </ul> |
| |
| |
| </div> |
| <!-- END CONTENT --> |
| |
| |
| <div id="footer"> |
| <p> |
| Previous Topic: <a href="user_agent.html">User Agent Class</a> |
| · |
| <a href="#top">Top of Page</a> · |
| <a href="../index.html">User Guide Home</a> · |
| Next Topic: <a href="zip.html">Zip Encoding Class</a> |
| </p> |
| <p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006-2010 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p> |
| </div> |
| |
| </body> |
| </html> |