get_levels() public method

Retrieve all subscription levels from the database
Since: 1.5
public get_levels ( $args = [] )
function rcp_get_subscription_levels($status = 'all')
{
    global $wpdb, $rcp_db_name;
    $rcp_levels = new RCP_Levels();
    $levels = $rcp_levels->get_levels(array('status' => $status));
    if ($levels) {
        return $levels;
    } else {
        return array();
    }
}
    /**
     * Render the options meta box
     *
     * @since 1.0
     * @return void
     */
    public function render_options_metabox()
    {
        global $post;
        if (!class_exists('RCP_Levels')) {
            echo __('<strong>Restrict Content Pro is not active. Please install and activate it.', 'edd-rcp');
            return;
        }
        $subscription = get_post_meta($post->ID, '_edd_rcp_discount_subscription', true);
        $amount = get_post_meta($post->ID, '_edd_rcp_discount_amount', true);
        $levels_db = new RCP_Levels();
        $levels = $levels_db->get_levels();
        ?>
		<table>
			<tr>
				<td>
					<label for="edd-rcp-subscription"><?php 
        _e('Subscription Level', 'edd-rcp');
        ?>
</label>
				</td>
				<td>
					<select name="_edd_rcp_discount_subscription" id="edd-rcp-subscription">
						<?php 
        foreach ($levels as $level) {
            ?>
							<option value="<?php 
            echo $level->id;
            ?>
"<?php 
            selected($subscription, $level->id);
            ?>
><?php 
            echo $level->name;
            ?>
</option>
						<?php 
        }
        ?>
					</select>
					<?php 
        _e('Choose the subscription levels members must have for this discount to apply.', 'edd-rcp');
        ?>
				</td>
			</tr>
			<tr>
				<td>
					<label for="edd-rcp-amount"><?php 
        _e('Discount Amount', 'edd-rcps');
        ?>
&nbsp;%&nbsp;</label>
				</td>
				<td>
					<input type="number" min="1" step="1" id="edd-rcp-amount" name="_edd_rcp_discount_amount" value="<?php 
        echo absint($amount);
        ?>
"/>
				</td>
			</tr>
		</table>
<?php 
        do_action('edd_rcp_discounts_options_metabox', $post->ID);
    }