Blame - user_guide/libraries/xmlrpc.html - code-igniter-v3-giggi

<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>

48

</tr>

49

</table>

50

<h1>XML-RPC and XML-RPC Server Classes</h1>

60

61

62

<p>CodeIgniter's XML-RPC classes permit you to send requests to another server, or set up

63

your own XML-RPC server to receive requests.</p>

<p>Quite simply it is a way for two computers to communicate over the internet using XML.

69

One computer, which we will call the <dfn>client</dfn>, sends an XML-RPC <strong>request</strong> to

70

another computer, which we will call the <dfn>server</dfn>. Once the server receives and processes the request it

71

will send back a <strong>response</strong> to the client.</p>

72

73

<p>For example, using the MetaWeblog API, an XML-RPC Client (usually a desktop publishing tool) will

74

send a request to an XML-RPC Server running on your site. This request might be a new weblog entry

75

being sent for publication, or it could be a request for an existing entry for editing.

76

77

When the XML-RPC Server receives this request it will examine it to determine which class/method should be called to process the request.

78

Once processed, the server will then send back a response message.</p>

79

80

<p>For detailed specifications, you can visit the <a href="http://www.xmlrpc.com/">XML-RPC</a> site.</p>

81

82

<h2>Initializing the Class</h2>

83

84

<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>

85

86

<p>To load the XML-RPC class you will use:</p>

87

<code>$this->load->library('xmlrpc');</code>

88

<p>Once loaded, the xml-rpc library object will be available using: <dfn>$this->xmlrpc</dfn></p>

89

90

<p>To load the XML-RPC Server class you will use:</p>

91

<code>

92

$this->load->library('xmlrpc');<br />

93

$this->load->library('xmlrpcs');

94

</code>

95

<p>Once loaded, the xml-rpcs library object will be available using: <dfn>$this->xmlrpcs</dfn></p>

96

97

<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>

102

103

<p>To send a request to an XML-RPC server you must specify the following information:</p>

104

105

<ul>

106

<li>The URL of the server</li>

107

<li>The method on the server you wish to call</li>

108

<li>The <em>request</em> data (explained below).</li>

109

</ul>

110

111

<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>

112

113

114

<code>$this->load->library('xmlrpc');<br />

115

<br />

116

$this->xmlrpc->server('http://rpc.pingomatic.com/', 80);<br />

117

$this->xmlrpc->method('weblogUpdates.ping');<br />

118

119

<br />

120

$request = array('My Photoblog', 'http://www.my-site.com/photoblog/');<br />

121

$this->xmlrpc->request($request);<br />

122

<br />

123

if ( ! $this->xmlrpc->send_request())<br />

124

{<br />

125

    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

131

request (in this case, the title and URL of your site) is placed into an array for transportation, and

132

compiled using the request() function.

133

Lastly, the full request is sent. If the <dfn>send_request()</dfn> method returns false we will display the error message

134

sent back from the XML-RPC Server.</p>

135

136

<h2>Anatomy of a Request</h2>

137

138

<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

139

is referred to as a <dfn>request parameter</dfn>. The above example has two parameters:

140

The URL and title of your site. When the XML-RPC server receives your request, it will look for parameters it requires.</p>

141

142

<p>Request parameters must be placed into an array for transportation, and each parameter can be one

143

of seven data types (strings, numbers, dates, etc.). If your parameters are something other than strings

144

you will have to include the data type in the request array.</p>

145

146

<p>Here is an example of a simple array with three parameters:</p>

147

148

<code>$request = array('John', 'Doe', 'www.some-site.com');<br />

149

$this->xmlrpc->request($request);</code>

150

151

<p>If you use data types other than strings, or if you have several different data types, you will place

152

each parameter into its own array, with the data type in the second position:</p>

153

154

<code>

155

$request = array (<br />

156

                   array('John', 'string'),<br />

157

                   array('Doe', 'string'),<br />

158

                   array(FALSE, 'boolean'),<br />

159

                   array(12345, 'int')<br />

160

                 );

161

<br />

162

$this->xmlrpc->request($request);</code>

163

164

The <a href="#datatypes">Data Types</a> section below has a full list of data types.

<h2>Creating an XML-RPC Server</h2>

169

170

<p>An XML-RPC Server acts as a traffic cop of sorts, waiting for incoming requests and redirecting them to the

171

appropriate functions for processing.</p>

172

173

<p>To create your own XML-RPC server involves initializing the XML-RPC Server class in your controller where you expect the incoming

174

request to appear, then setting up an array with mapping instructions so that incoming requests can be sent to the appropriate

175

class and method for processing.</p>

176

177

<p>Here is an example to illustrate:</p>

178

179

<code>

180

$this->load->library('xmlrpc');<br />

181

$this->load->library('xmlrpcs');<br />

182

<br />

183

$config['functions']['<var>new_post</var>']  = array('function' => '<dfn>My_blog.new_entry</dfn>');<br />

184

$config['functions']['<var>update_post</var>'] = array('function' => '<dfn>My_blog.update_entry</dfn>');<br />

185

<br />

186

$this->xmlrpcs->initialize($config);<br />

187

$this->xmlrpcs->serve();</code>

188

189

<p>The above example contains an array specifying two method requests that the Server allows.

190

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>

191

192

<p>In other words, if an XML-RPC Client sends a request for the <var>new_post</var> method, your

193

server will load the <dfn>My_blog</dfn> class and call the <dfn>new_entry</dfn> function.

194

If the request is for the <var>update_post</var> method, your

195

server will load the <dfn>My_blog</dfn> class and call the <dfn>update_entry</dfn> function.</p>

196

197

<p>The function names in the above example are arbitrary. You'll decide what they should be called on your server,

198

or if you are using standardized APIs, like the Blogger or MetaWeblog API, you'll use their function names.</p>

199

200

201

<h2>Processing Server Requests</h2>

202

203

<p>When the XML-RPC Server receives a request and loads the class/method for processing, it will pass

204

an object to that method containing the data sent by the client.</p>

205

206

<p>Using the above example, if the <var>new_post</var> method is requested, the server will expect a class

207

to exist with this prototype:</p>

208

209

<code>class <kbd>My_blog</kbd> extends Controller {<br />

210

<br />

211

    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.

219

Using this object you will have access to the <em>request parameters</em> enabling you to process the request. When

220

you are done you will send a <dfn>Response</dfn> back to the Client.</p>

221

222

<p>Below is a real-world example, using the Blogger API. One of the methods in the Blogger API is <dfn>getUserInfo()</dfn>.

223

Using this method, an XML-RPC Client can send the Server a username and password, in return the Server sends

224

back information about that particular user (nickname, user ID, email address, etc.). Here is how the processing

225

function might look:</p>

226

227

228

<code>class <kbd>My_blog</kbd> extends Controller {<br />

229

<br />

230

    function <kbd>getUserInfo</kbd>(<var>$request</var>)<br />

231

    {<br />

232

233

        $username = 'smitty';<br />

234

        $password = 'secretsmittypass';<br /><br />

235

236

        $this->load->library('xmlrpc');<br />

237

    <br />

238

        $parameters = $request->output_parameters();<br />

239

    <br />

240

        if ($parameters['1'] != $username AND $parameters['2'] != $password)<br />

241

        {<br />

242

            return $this->xmlrpc->send_error_message('100', 'Invalid Access');<br />

243

        }<br />

244

    <br />

245

        $response = array(array('nickname'  => array('Smitty','string'),<br />

246

                                'userid'    => array('99','string'),<br />

247

                                'url'       => array('http://yoursite.com','string'),<br />

248

                                'email'     => array('jsmith@yoursite.com','string'),<br />

249

                                'lastname'  => array('Smith','string'),<br />

250

                                'firstname' => array('John','string')<br />

251

                                ),<br />

252

                         'struct');<br />

253

<br />

254

        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.

261

In the above example, the output parameters will be the username and password.</p>

262

263

<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>

264

265

<p>If the operation was successful, the client will be sent back a response array containing the user's info.</p>

266

267

268

<h2>Formatting a Response</h2>

269

270

<p>Similar to <em>Requests</em>, <em>Responses</em> must be formatted as an array. However, unlike requests, a response is an array

271

<strong>that contains a single item</strong>. This item can be an array with several additional arrays, but there

272

can be only one primary array index. In other words, the basic prototype is this:</p>

273

274

<code>$response = array('Response data', 'array');</code>

275

276

<p>Responses, however, usually contain multiple pieces of information. In order to accomplish this we must put the response into its own

277

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>

278

279

<code>

280

$response = array (<br />

281

                   array(<br />

282

                         'first_name' => array('John', 'string'),<br />

283

                         'last_name' => array('Doe', 'string'),<br />

284

                         'member_id' => array(123435, 'int'),<br />

285

                         'todo_list' => array(array('clean house', 'call mom', 'water plants'), 'array'),<br />

286

                        ),<br />

287

                 '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>

292

293

<p>As with Requests, a response can be on of the seven data types listed in the <a href="#datatypes">Data Types</a> section.</p>

294

295

296

<h2>Sending an Error Response</h2>

297

298

<p>If you need to send the client an error response you will use the following:</p>

299

300

<code>return $this->xmlrpc->send_error_message('123', 'Requested data not available');</code>

301

302

<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>

310

311

<p>To help you understand everything we've covered thus far, let's create a couple controllers that act as

312

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>.

317

In it, place this code and save it to your <samp>applications/controllers/</samp> folder:</p>

318

319

<textarea class="textarea" style="width:100%" cols="50" rows="32"><?php

320

321

class Xmlrpc_client extends Controller {

function index()

{

$this->load->helper('url');

326

$server_url = site_url('xmlrpc_server');

327

328

$this->load->library('xmlrpc');

329

330

$this->xmlrpc->server($server_url, 80);

331

$this->xmlrpc->method('Greetings');

332

333

$request = array('How is it going?');

334

$this->xmlrpc->request($request);

335

336

if ( ! $this->xmlrpc->send_request())

337

{

338

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>.

355

In it, place this code and save it to your <samp>applications/controllers/</samp> folder:</p>

356

357

<textarea class="textarea" style="width:100%" cols="50" rows="30"><?php

358

359

class Xmlrpc_server extends Controller {

function index()

{

$this->load->library('xmlrpc');

364

$this->load->library('xmlrpcs');

365

366

$config['functions']['Greetings'] = array('function' => 'Xmlrpc_server.process');

367

368

$this->xmlrpcs->initialize($config);

369

$this->xmlrpcs->serve();

}

function process($request)

374

{

375

$parameters = $request->output_parameters();

$response = array(

array(

'you_said' => $parameters['0'],

380

'i_respond' => 'Not bad at all.'),

381

'struct');

382

383

return $this->xmlrpc->send_response($response);

}

}

?></textarea>

<p>Now visit the your site using a URL similar to this:</p>

391

<code>www.your-site.com/index.php/<var>xmlrpc_client</var>/</code>

392

393

<p>You should now see the message you sent to the server, and its response back to you.</p>

394

395

<p>The client you created sends a message ("How's is going?") to the server, along with a reqest for the "Greetings" method.

396

The Server receives the request and maps it to the "process" function, where a response is sent back.</p>

<h1>XML-RPC Function Reference</h1>

402

403

<h2>$this->xmlrpc->server()</h2>

404

<p>Sets the URL and port number of the server to which a request is to be sent:</p>

405

<code>$this->xmlrpc->server('http://www.sometimes.com/pings.php', 80);</code>

406

407

<h2>$this->xmlrpc->timeout()</h2>

408

<p>Set a time out period (in seconds) after which the request will be canceled:</p>

409

<code>$this->xmlrpc->timeout(6);</code>

410

411

<h2>$this->xmlrpc->method()</h2>

412

<p>Sets the method that will be requested from the XML-RPC server:</p>

413

<code>$this->xmlrpc->method('<var>method</var>');</code>

414

415

<p>Where <var>method</var> is the name of the method.</p>

416

417

<h2>$this->xmlrpc->request()</h2>

418

<p>Takes an array of data and builds request to be sent to XML-RPC server:</p>

419

<code>$request = array(array('My Photoblog', 'string'), 'http://www.yoursite.com/photoblog/');<br />

420

$this->xmlrpc->request($request);</code>

421

422

<h2>$this->xmlrpc->send_request()</h2>

423

<p>The request sending function. Returns boolean TRUE or FALSE based on success for failure, enabling it to be used conditionally.</p>

424

425

<h2>$this->xmlrpc->set_debug(TRUE);</h2>

426

<p>Enables debugging, which will display a variety of information and error data helpful during development.</p>

427

428

429

<h2>$this->xmlrpc->display_error()</h2>

430

<p>Returns an error message as a string if your request failed for some reason.</p>

431

<code>echo $this->xmlrpc->display_error();</code>

432

433

<h2>$this->xmlrpc->display_response()</h2>

434

<p>Returns the response from the remote server once request is received. The response will typically be an associative array.</p>

435

<code>$this->xmlrpc->display_response();</code>

436

437

<h2>$this->xmlrpc->send_error_message()</h2>

438

<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

439

is the error message.</p>

440

<code>return $this->xmlrpc->send_error_message('123', 'Requested data not available');</code>

441

442

<h2>$this->xmlrpc->send_response()</h2>

443

<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>

444

<code>$response = array(<br />

445

                 array(<br />

446

                        'flerror' => array(FALSE, 'boolean'),<br />

447

                        'message' => "Thanks for the ping!")<br />

448

                     )<br />

449

                 'struct');<br />

450

return $this->xmlrpc->send_response($response);</code>

<h2>Data Types</h2>

<p>According to the <a href="http://www.xmlrpc.com/spec">XML-RPC spec</a> there are seven types

457

of values that you can send via XML-RPC:</p>

<ul>

<li><em>boolean</em></li>

462

<li><em>string</em></li>

463

<li><em>double</em></li>

464

<li><em>dateTime.iso8601</em></li>

465

466

<li><em>struct</em> (contains array of values)</li>

467

<li><em>array</em> (contains array of values)</li>

</ul>

</div>

<p>

Previous Topic:  <a href="validation.html">Validation Class</a>

478

   ·  

479

<a href="#top">Top of Page</a>   ·  

480

<a href="../index.html">User Guide Home</a>   ·  

481

Next Topic:  <a href="zip.html">Zip Encoding Class</a>

482

</p>

Derek Jones

7a9193a

2008-01-21 18:39:20 +0000

[diff] [blame]

483

Derek Allard

39b622d

2008-01-16 21:10:09 +0000

[diff] [blame]

</div>

</body>

</html>