如何解决CampaignMonitorAPI集成问题？使用Composer和createsend-php库可以轻松实现！

<code>composer require campaignmonitor/createsend-php</code>

<code>{
    "require": {
        "campaignmonitor/createsend-php": "{version}"
    }
}</code>

<code>composer update</code>

<code class="php">require_once 'csrest_general.php';

$authorize_url = CS_REST_General::authorize_url(
    'Client ID for your application',
    'Redirect URI for your application',
    'The permission level your application requires',
    'Optional state data to be included'
);
// Redirect your users to $authorize_url.</code>

<code class="php">require_once 'csrest_general.php';

$result = CS_REST_General::exchange_token(
    'Client ID for your application',
    'Client Secret for your application',
    'Redirect URI for your application',
    'A unique code for your user' // Get the code parameter from the query string
);

if ($result->was_successful()) {
    $access_token = $result->response->access_token;
    $expires_in = $result->response->expires_in;
    $refresh_token = $result->response->refresh_token;
    // Save $access_token, $expires_in, and $refresh_token.
} else {
    echo 'An error occurred:\n';
    echo $result->response->error.': '.$result->response->error_description."\n";
    // Handle error...
}</code>

<code class="php">require_once 'csrest_general.php';

$auth = array(
    'access_token' => 'your access token',
    'refresh_token' => 'your refresh_token');
$wrap = new CS_REST_General($auth);

$result = $wrap->get_clients();
var_dump($result->response);</code>

<code class="php">require_once 'csrest_general.php';

$auth = array(
    'access_token' => 'your access token',
    'refresh_token' => 'your refresh token'
);
$wrap = new CS_REST_General($auth);
$result = $wrap->get_clients();
if (!$result->was_successful()) {
    // If you receive '121: Expired OAuth Token', refresh the access token
    if ($result->response->Code == 121) {
        list($new_access_token, $new_expires_in, $new_refresh_token) = 
            $wrap->refresh_token();
        // Save $new_access_token, $new_expires_in, and $new_refresh_token
    }
    // Make the call again
    $result = $wrap->get_clients();
}
var_dump($result->response);</code>