Project Vote Smart API

Example Usage

Here is an example of interfacing with our backend using PHP with the SimpleXML extension. This example centers around the District class.

We have three files here which will be described below.

showdistrict.php: This file merges the HTML and data pulled from the PVS API. It's also the controler which initializes the data gathering object
config.php: This file contains the various configuration we will need. Storing things like the auth key and server hostname.
District.php: This file, while remarkably simple is what does the heavy lifting. It contacts the server, retrieves the XML and stores it in a SimpleXML data object

showdistrict.php

<?php

require_once("District.php");

// Initialize the District class
$district_object = new District();

// Get the SimpleXML object
$x = $district_object->getByOfficeState(6, 'PA');

echo '
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<!-- pwned -->
<html lang="en">
<body>';

// Check and make sure there is no error

if (isset($x->error_message)) { // If there is, let's handle it
        
        echo '
        <div>' . $x->errorMessage . '</div>';
        
} else { // If not, let's go ->
        
        echo '
        <div>
                <a href="' . $x->generalInfo->linkBack . '">' . $x->generalInfo->title . '</a>
        </div>
        <br /><br />
        <table>
                <tr>
                        <td>ID</td>
                        <td>Name</td>
                        <td>Office ID</td>
                        <td>State ID</td>
                </tr>
                ';
        
        // Since there are multiple districts, $x->district is actually an
        // array of other objects that we need to iterate through
        foreach ($x->district as $district) {
                
                echo '
                <tr>
                        <td>' . $district->id . '</td>
                        <td>' . $district->name . '</td>
                        <td>' . $district->officeId . '</td>
                        <td>' . $district->stateId . '</td>
                </tr>';
                
        }
        
}

echo '
</body>
</html>';

?>

config.php

<?php

define(_KEY_, "14fc970964e42f6eac640f4531f000b5");      // Authentication key provided to you

define(_OUTPUT_, "XML");        // Don't change this unless you have to
                                // XML/JSON
                                
define(_ERRORLEVEL_, 0);        // 0 - displays basic errors
                                // 1 - more detailed errors
                                
if (_ERRORLEVEL_ >= 1) {
        error_reporting(E_ALL ^ E_NOTICE); // All but notice errors
} else {
        error_reporting(E_NONE);
}
                                
define(_APISERVER_, "http://api.votesmart.org");       // Without trailing slash and with protocol

District.php

<?php

require_once("config.php");

class District {
        
        public function getByOfficeState($office_id, $state_id) {
                
                $iface = "/District.getByOfficeState";
                $args = "?key=" . _KEY_ . "&o=" . _OUTPUT_ . "&officeId=" . $office_id . "&stateId=" . $state_id;
                
                if (!$xml = file_get_contents(_APISERVER_ . $iface . $args)) {
                        
                        return false;
                        
                } else {
                        
                        // Let's use the SimpleXML to drop the whole XML
                        // output into an object we can later interact with easilly
                        $xml_object = new SimpleXMLElement($xml);
                        
                        return $xml_object;
                        
                }
                
        }
        
}

PVS API

Usage

Objects

Example Usage

showdistrict.php

config.php

District.php