repo_zf1/documentation/manual/en/module_specs/Zend_Rest_Client.xml

<?xml version="1.0" encoding="UTF-8"?>
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<sect1 id="zend.rest.client">
    <title>Zend_Rest_Client</title>

    <sect2 id="zend.rest.client.introduction">
        <title>Introduction</title>

        <para>
            Using the <classname>Zend_Rest_Client</classname> is very similar to using
            <code>SoapClient</code> objects (<ulink
            url="http://www.php.net/soap">SOAP web service extension</ulink>).
            You can simply call the REST service procedures as
            <classname>Zend_Rest_Client</classname> methods. Specify the service's full
            address in the <classname>Zend_Rest_Client</classname> constructor.
        </para>

        <example id="zend.rest.client.introduction.example-1">
            <title>A basic REST request</title>

            <programlisting language="php"><![CDATA[
/**
 * Connect to framework.zend.com server and retrieve a greeting
 */
$client = new Zend_Rest_Client('http://framework.zend.com/rest');

echo $client->sayHello('Davey', 'Day')->get(); // "Hello Davey, Good Day"
]]></programlisting>
        </example>

        <note>
            <title>Differences in calling</title>

            <para>
                <classname>Zend_Rest_Client</classname> attempts to make remote methods
                look as much like native methods as possible, the only
                difference being that you must follow the method call with one
                of either <methodname>get()</methodname>, <methodname>post()</methodname>,
                <methodname>put()</methodname> or <methodname>delete()</methodname>. This call may
                be made via method chaining or in separate method calls:
            </para>

            <programlisting language="php"><![CDATA[
$client->sayHello('Davey', 'Day');
echo $client->get();
]]></programlisting>
        </note>
    </sect2>

    <sect2 id="zend.rest.client.return">
        <title>Responses</title>

        <para>
            All requests made using <classname>Zend_Rest_Client</classname> return a
            <classname>Zend_Rest_Client_Response</classname> object. This object has many
            properties that make it easier to access the results.
        </para>

        <para>
            When the service is based on <classname>Zend_Rest_Server</classname>,
            <classname>Zend_Rest_Client</classname> can make several assumptions about the
            response, including response status (success or failure) and return
            type.
        </para>

        <example id="zend.rest.client.return.example-1">
            <title>Response Status</title>

            <programlisting language="php"><![CDATA[
$result = $client->sayHello('Davey', 'Day')->get();

if ($result->isSuccess()) {
    echo $result; // "Hello Davey, Good Day"
}
]]></programlisting>
        </example>

        <para>
            In the example above, you can see that we use the request result as
            an object, to call <methodname>isSuccess()</methodname>, and then because of
            <methodname>__toString()</methodname>, we can simply <code>echo</code> the
            object to get the result. <classname>Zend_Rest_Client_Response</classname>
            will allow you to echo any scalar value. For complex types, you can
            use either array or object notation.
        </para>

        <para>
            If however, you wish to query a service not using
            <classname>Zend_Rest_Server</classname> the
            <classname>Zend_Rest_Client_Response</classname> object will behave more like
            a <code>SimpleXMLElement</code>. However, to make things easier, it
            will automatically query the <acronym>XML</acronym> using XPath if the property is not
            a direct descendant of the document root element. Additionally, if
            you access a property as a method, you will receive the <acronym>PHP</acronym> value
            for the object, or an array of <acronym>PHP</acronym> value results.
        </para>

        <example id="zend.rest.client.return.example-2">
            <title>Using Technorati's Rest Service</title>

            <programlisting language="php"><![CDATA[
$technorati = new Zend_Rest_Client('http://api.technorati.com/bloginfo');
$technorati->key($key);
$technorati->url('http://pixelated-dreams.com');
$result = $technorati->get();
echo $result->firstname() .' '. $result->lastname();
]]></programlisting>
        </example>

        <example id="zend.rest.client.return.example-3">
            <title>Example Technorati Response</title>

            <programlisting language="xml"><![CDATA[
<?xml version="1.0" encoding="utf-8"?>
<!-- generator="Technorati API version 1.0 /bloginfo" -->
<!DOCTYPE tapi PUBLIC "-//Technorati, Inc.//DTD TAPI 0.02//EN"
                      "http://api.technorati.com/dtd/tapi-002.xml">
<tapi version="1.0">
    <document>
        <result>
            <url>http://pixelated-dreams.com</url>
            <weblog>
                <name>Pixelated Dreams</name>
                <url>http://pixelated-dreams.com</url>
                <author>
                    <username>DShafik</username>
                    <firstname>Davey</firstname>
                    <lastname>Shafik</lastname>
                </author>
                <rssurl>
                    http://pixelated-dreams.com/feeds/index.rss2
                </rssurl>
                <atomurl>
                    http://pixelated-dreams.com/feeds/atom.xml
                </atomurl>
                <inboundblogs>44</inboundblogs>
                <inboundlinks>218</inboundlinks>
                <lastupdate>2006-04-26 04:36:36 GMT</lastupdate>
                <rank>60635</rank>
            </weblog>
            <inboundblogs>44</inboundblogs>
            <inboundlinks>218</inboundlinks>
        </result>
    </document>
</tapi>
]]></programlisting>
        </example>

        <para>
            Here we are accessing the <code>firstname</code> and
            <code>lastname</code> properties. Even though these are not
            top-level elements, they are automatically returned when accessed by
            name.
        </para>

        <note>
            <title>Multiple items</title>

            <para>
                If multiple items are found when accessing a value by name, an
                array of SimpleXMLElements will be returned; accessing via
                method notation will return an array of <acronym>PHP</acronym> values.
            </para>
        </note>
    </sect2>

    <sect2 id="zend.rest.client.args">
        <title>Request Arguments</title>

        <para>
            Unless you are making a request to a <classname>Zend_Rest_Server</classname>
            based service, chances are you will need to send multiple arguments
            with your request. This is done by calling a method with the name of
            the argument, passing in the value as the first (and only) argument.
            Each of these method calls returns the object itself, allowing for
            chaining, or "fluent" usage. The first call, or the first argument
            if you pass in more than one argument, is always assumed to be the
            method when calling a <classname>Zend_Rest_Server</classname> service.
        </para>

        <example id="zend.rest.client.args.example-1">
            <title>Setting Request Arguments</title>

            <programlisting language="php"><![CDATA[
$client = new Zend_Rest_Client('http://example.org/rest');

$client->arg('value1');
$client->arg2('value2');
$client->get();

// or

$client->arg('value1')->arg2('value2')->get();
]]></programlisting>
        </example>

        <para>
            Both of the methods in the example above, will result in the
            following get args:
            <code>?method=arg&amp;arg1=value1&amp;arg=value1&amp;arg2=value2</code>
        </para>

        <para>
            You will notice that the first call of
            <code>$client->arg('value1');</code> resulted in both
            <code>method=arg&amp;arg1=value1</code> and <code>arg=value1</code>;
            this is so that <classname>Zend_Rest_Server</classname> can understand the
            request properly, rather than requiring pre-existing knowledge of
            the service.
        </para>

        <warning>
            <title>Strictness of Zend_Rest_Client</title>

            <para>
                Any REST service that is strict about the arguments it receives will likely fail
                using <classname>Zend_Rest_Client</classname>, because of the behavior described
                above. This is not a common practice and should not cause problems.
            </para>
        </warning>
    </sect2>
</sect1>
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