<?php

class RandomPostWidget extends WP_Widget
{
  function RandomPostWidget()
  {
    $widget_ops = array('classname' => 'RandomPostWidget', 'description' => 'Displays a featured post' );
    $this->WP_Widget('RandomPostWidget', 'Featured Homepage Post', $widget_ops);
  }

  function form($instance)
{
    $instance = wp_parse_args( (array) $instance, array( 'page_id' => '' ) );
    $title = $instance['page_id'];
?>
    <select label="<?php echo $this->get_field_id('title'); ?>">>
        <?php
        global $post;
        $args = array( 'numberposts' => -1,'category' => 5);
        $posts = get_posts($args);
        foreach( $posts as $post )
{
    setup_postdata($post); ?>
        <option value="<? echo $post->ID; ?>" <?php
        selected( $instance['page_id'], $post->ID );
        ?>><?php the_title(); ?></option>
<?php
}
  function update($new_instance, $old_instance)
  {
    $instance = $old_instance;
    $instance['page_id'] = $new_instance['page_id'];
    return $instance;
  }

  function widget($args, $instance)
{
    $post = get_post( $instance['page_id'] );
    echo $post->post_content; // you should add the common filters here ?>

    <div id="%1$s" class="widget %2$s">
    <p class="title"><?php echo the_title(); ?></p>

    <?php $attachment_id = get_field('main_image');
    $size = "home-boxes";
    $image = wp_get_attachment_image_src( $attachment_id, $size );
    ?>

    <a href="<?php the_permalink(); ?>">
        <img class="headline" width="<?php echo $image[1]; ?>" height="<?php echo $image[2]; ?>" src="<?php echo $image[0]; ?>" />
    </a>

    </div>

<?php }

}
add_action( 'widgets_init', create_function('', 'return register_widget("RandomPostWidget");') );


?>