widget.php

<?php

add_action( 'widgets_init', 'babble_widget' );
function babble_widget() {
	register_widget( 'Babble_Widget' );
}

class Babble_Widget extends WP_Widget {

	public $defaults = array(
		'show_if_unavailable' => 'off',
		'show_as'             => 'dropdown',
	);

	function __construct() {
		parent::__construct(
			'bbl_widget', // Base ID
			__('Language Switcher','babble'), // Name
			array( 'description' => __('Displays a list of links to translations / equivalent pages.', 'babble') ) // Args
		);
	}

	function widget( $args, $instance ) {

		$args = array_merge( array(
			'show_as' => 'dropdown',
		), $args );

		echo $args['before_widget'];

		echo $args['before_title'] . __( 'Languages', 'babble' ) . $args['after_title'];

		$list = bbl_get_switcher_links();

		switch ( $instance['show_as'] ) {

		case 'dropdown':
			echo '<select onchange="document.location.href=this.options[this.selectedIndex].value;">';
			foreach ( $list as $item ) :

				if ( $item['active'] ) {
					$selected = 'selected="selected" ';
				} else {
					$selected = '';
				}

				if ( in_array( 'bbl-add',$item['classes'] ) ) {
					/*
						We're logged in, there's no translation
						of this page as yet, but the user has the
						ability to create one; so here's a link
						to allow him/her to do so
					*/
					echo '<option ' . $selected . 'class="' . esc_attr( $item[ 'class' ] ) . '" value="' . esc_url( $item[ 'href' ] ) . '">' . esc_html( $item[ 'lang' ]->display_name ) . ' [' . __('Add') . ']</option>';
				}
				elseif ( $item[ 'href'] ) {
					/*
						Means there is a translation of this page
						into the language in question
					*/
					echo '<option ' . $selected . 'class="' . esc_attr( $item[ 'class' ] ) . '" value="' . esc_url( $item[ 'href' ] ) . '">' . esc_html( $item[ 'lang' ]->display_name ) . '</option>';
				}
				elseif ( 'on' === $instance['show_if_unavailable'] ) {
					/*
						We're on the front end, but there is
						no translation into this language as yet;
						the user has said 'Show if unavailable'
						in the widget management screen.
						Applies a no-translation class to the <li>,
						and a bbl-no-translation class to the <div>
						in case you want to 'grey it out' somehow
					*/
					echo '<option disabled class="' . esc_attr( $item[ 'class' ] ) . '" value="">' . esc_html( $item[ 'lang' ]->display_name ) . '</option>';
				}
			endforeach;
			echo '</select>';
		break;

		case 'list':
			echo '<ul class="languages_list">';
			foreach ( $list as $item ) :

				if ( in_array( 'bbl-add',$item['classes'] ) ) {
					/*
						We're logged in, there's no translation
						of this page as yet, but the user has the
						ability to create one; so here's a link
						to allow him/her to do so
					*/
					echo '<li><a href="' . esc_url( $item[ 'href' ] ) . '" class="' . esc_attr( $item[ 'class' ] ) . '">' . esc_html( $item[ 'lang' ]->display_name ) . ' [' . __( 'Add', 'babble' ) . ']</a></li>';
				}
				elseif ( $item[ 'href'] ) {
					/*
						Means there is a translation of this page
						into the language in question
					*/
					echo '<li><a href="' . esc_url( $item[ 'href' ] ) . '" class="' . esc_attr( $item[ 'class' ] ) . '">' . esc_html( $item[ 'lang' ]->display_name ) . '</a></li>';
				}
				elseif ( 'on' === $instance['show_if_unavailable'] ) {
					/*
						We're on the front end, but there is
						no translation into this language as yet;
						the user has said 'Show if unavailable'
						in the widget management screen.
						Applies a no-translation class to the <li>,
						and a bbl-no-translation class to the <div>
						in case you want to 'grey it out' somehow
					*/
					echo '<li class="no-translation"><div class="bbl-no-translation">' . esc_html( $item[ 'lang' ]->display_name ) . '</div></li>';
				}

			endforeach;
			echo '</ul>';
		break;

		}

		echo $args['after_widget'];
	}

	function update( $new_instance, $old_instance ) {

		$new_instance = array_merge( $this->defaults, $new_instance );
		$new_instance['show_as'] = strip_tags( $new_instance['show_as'] );
		$new_instance['show_if_unavailable'] = strip_tags( $new_instance['show_if_unavailable'] );

		return $new_instance;

	}

	function form( $instance ) {

		global $wpdb;
		$instance = wp_parse_args( $instance, $this->defaults );

		?>
		<p>
			<?php _e('Show as:','babble'); ?>
			<select id="<?php echo $this->get_field_id('show_as'); ?>" name="<?php echo $this->get_field_name('show_as'); ?>">
				<option value="dropdown" <?php selected( $instance['show_as'],'dropdown' ); ?>><?php _e('Dropdown','babble'); ?></option>
				<option value="list" <?php selected( $instance['show_as'],'list' ); ?>><?php _e('List','babble'); ?></option>
			</select>
		</p>
		<p>
			<input id="<?php echo $this->get_field_id('show_if_unavailable'); ?>" name="<?php echo $this->get_field_name('show_if_unavailable'); ?>" type="checkbox" <?php checked( 'on', $instance['show_if_unavailable'] ); ?> />
			<label for="<?php echo $this->get_field_id('show_if_unavailable'); ?>"><?php _e('Show all languages in widget, even if there is no translation', 'babble'); ?></label>
		</p>
		<p class="description">
			<?php _e("Don't worry: if there's no equivalent page, the link won't be clickable.","babble"); ?>
		</p>
		<p class="description">
			<?php _e("Links allowing logged-in administrators to add translations will always be shown.","babble"); ?>
		</p>

		<?php
	}
}