gistfile1.txt

<?php
/*
Plugin Name: MyWidget
Description: Description
Author: Pixolin
*/


/********************
* add a new Widget to WP_Widget class
* use a unique name by prefixing the class name
*/
class awesome_Widget extends WP_Widget {

/********************
* BACK END: The Widget as it appears in the back end in the left Widgets pane
*/
function awesome_Widget() {
    $widget_ops = array(
        'classname' => 'awesomewidget', // CSS class for the widget Front end
        'description' => 'Description: Widget showing Book Recommendation'  // Describes, what the widget is good for
    );

    /*
    * give this widget a CSS class .pix_widget for use in wp-admin,
    * give it a title 'Awesome widget' and use $widget_ops as set above
    */
    $this->WP_Widget( 'pix_widget', 'Awesome widget', $widget_ops );
}

/********************
* BACK END FORM when dragged into the preserved place, e.g. sidebar
* $instance is a unique number for various instances of the same widget being used
*/
function form( $instance ) {

    //Defaults in case nothing is set
    $defaults = array(
        'title'=> 'Book of the Day',
        'book' => 'Robinson Crusoe');

    $instance = wp_parse_args( (array) $instance, $defaults );

    $title = $instance['title'];
    $book  = $instance['book'];
    ?>
    <p>Title: <input class="widefat" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>"></p>
    <p>Book: <input class="widefat" name="<?php echo $this->get_field_name( 'book' ); ?>" type="text" value="<?php echo esc_attr( $book ); ?>"></p>
    <?php

}

/********************
* SAVE the updates made in the BACK END FORM
*/
function update( $new_instance, $old_instance ) {
    $instance = $old_instance;
    $instance['title']= strip_tags( $new_instance['title'] );
    $instance['book']= strip_tags( $new_instance['book'] );
    return $instance;
}

/********************
* OUTPUT of the Widget Frontend, using $args (settings *what* to display) and
* $instance (settings for which instance of the plugin the $args were set)
* $args holds value such as the tag being used 'before_widget', but also arguments
* for e.g. a query
*/
function widget( $args, $instance ) {

    // first we need to extract the associative array with information what tags to use before and after widget into single variables...
    extract( $args );

    // we use here extracted variables here
    echo $before_widget;

    // we want to display the value of variable $book for this $instance of the widget
    $title = $instance['title'];
    $book  = $instance['book'];

    if (!empty($title)) {
        echo $before_title; //tag before title
        echo $title;
        echo $after_title; //closing tag after title
        }

    if (!empty($book)) {
      echo "We recommend today: <br><strong>" . $book . "</strong>";
      }

    echo $after_widget;
}
}
/********************
* Now we use a function to register the widget
*/
function register_awesome_Widget() {
    register_widget( 'awesome_Widget' );
}

/********************
* Finally let's hook it
*/
add_action( 'widgets_init', 'register_awesome_Widget' );