gomoob/php-facebook-messenger

<?php

/**
 * BSD 3-Clause License
 *
 * Copyright (c) 2017, GOMOOB All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this list of conditions and the following
 *   disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
namespace Gomoob\FacebookMessenger\Model\Attachment;

use Gomoob\FacebookMessenger\Model\AttachmentInterface;

/**
 * Abstract class common to all Facebook Messenger message attachments.
 *
 * @author Baptiste GAILLARD (baptiste.gaillard@gomoob.com)
 * @see https://developers.facebook.com/docs/messenger-platform/send-api-reference
 */
abstract class AbstractAttachment implements AttachmentInterface
{
    /**
     * The payload of the button model.
     *
     * @var \Gomoob\FacebookMessenger\Model\PayloadInterface
     */
    protected $payload;

    /**
     * {@inheritDoc}
     */
    public function getPayload()
    {
        return $this->payload;
    }

    /**
     * {@inheritDoc}
     */
    public function setPayload(/* PayloadInterface */ $payload)
    {
        // First checks the payload is of the right type
        $this->doCheckPayloadType($payload);

        // Sets the payload
        $this->payload = $payload;

        // Returns this instance
        return $this;
    }

    /**
     * Checks that the payload tranmistted to the attachment is of the right type.
     *
     * @param \Gomoob\FacebookMessenger\Model\PayloadInterface $payload the payload to check.
     *
     * @throws \Gomoob\FacebookMessenger\Exception\FacebookMessengerException if the provided payload has not the right
     *         type.
     */
    abstract protected function doCheckPayloadType(/* PayloadInterface */ $payload);
}