Truncated Archives Widget - A variation on the core Archives widget where it is like a yearly list in addition to the months of the current year. https://www.damiencarbery.com/2020/09/truncated-archives-widget/

truncated-archives-widget.php

<?php
/*
Plugin Name: Truncated Archives Widget
Plugin URI: https://www.damiencarbery.com/2020/09/truncated-archives-widget/
Description: A variation on the core Archives widget where it is like a yearly list in addition to the months of the current year.
Author: Damien Carbery
Version: 0.1
*/

class Truncated_Archives_Widget extends WP_Widget {
	/**
	 * Holds widget settings defaults, populated in constructor.
	 *
	 * @var array
	 */
	protected $defaults;
	
	private $this_year;

	/**
	 * Constructor. Set the default widget options and create widget.
	 *
	 * @since 1.0.0
	 */
	public function __construct() {

		$this->this_year = date( 'Y' );
		$this->defaults = [
			'title'               => '',
			'remove_year_suffix' => 0,
			'include_this_year'   => 1,
		];

		$widget_ops = [
			'classname'   => 'truncated-archives-widget widget_archive',
			'description' => __( 'A yearly archive of your site with months of current year.', 'taw_widget' ),
		];

		parent::__construct( 'truncated-archives-widget', __( 'Truncated Archives', 'taw_widget' ), $widget_ops );

	}


	// Filter the array to exclude strings that do not have the current year.
	function archive_exclude_previous_years($item) {
		// Look for '2020</a>'
		if (false === strpos($item, $this->this_year . '</a>')) {
			return false;
		}
		return true;
	}


	// Remove the ' 2020' (space + year) string.
	function remove_year($item) {
		return str_replace(' ' . $this->this_year, '', $item);
	}


	/**
	 * Outputs the content for the current Archives widget instance.
	 *
	 * @since 2.8.0
	 *
	 * @param array $args     Display arguments including 'before_title', 'after_title',
	 *                        'before_widget', and 'after_widget'.
	 * @param array $instance Settings for the current Archives widget instance.
	 */
	public function widget( $args, $instance ) {
		$default_title = __( 'Archives' );
		$title         = ! empty( $instance['title'] ) ? $instance['title'] : $default_title;

		/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
		$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );

		$remove_year_suffix = ! empty( $instance['remove_year_suffix'] ) ? 1 : 0;
		$include_this_year = ! empty( $instance['include_this_year'] ) ? 1 : 0;

		echo $args['before_widget'];

		if ( $title ) {
			echo $args['before_title'] . $title . $args['after_title'];
		}

		$format = current_theme_supports( 'html5', 'navigation-widgets' ) ? 'html5' : 'xhtml';

		/** This filter is documented in wp-includes/widgets/class-wp-nav-menu-widget.php */
		$format = apply_filters( 'navigation_widgets_format', $format );

		if ( 'html5' === $format ) {
			// The title may be filtered: Strip out HTML and make sure the aria-label is never empty.
			$title      = trim( strip_tags( $title ) );
			$aria_label = $title ? $title : $default_title;
			echo '<nav role="navigation" aria-label="' . esc_attr( $aria_label ) . '">';
		}
		
		// Get links to yearly archives.
		$args = array( 'type' => 'yearly', 'echo' => false, 'format' => 'custom', 'before' => '', 'after' => '|' );
		$yearly_archives_string = wp_get_archives( $args );
		$yearly_archives = array_map( 'trim', explode( '|', $yearly_archives_string ) );

		// Get links to monthly archives and remove all that aren't this year.
		$args = array( 'type' => 'monthly', 'echo' => false, 'format' => 'custom', 'before' => '', 'after' => '|' );
		$monthly_archives_string = wp_get_archives($args);
		$monthly_archives = array_filter( array_map('trim', explode('|', $monthly_archives_string)), array( $this, 'archive_exclude_previous_years' ) );
		// Optionally remove year from this year's links e.g. "August 2020" -> "August".
		if ( $remove_year_suffix ) {
			$monthly_archives = array_map( array( $this, 'remove_year' ), $monthly_archives );
		}

		// If there are any posts this year then insert the links after the year link.
		$archives_list = array();
		if (count($monthly_archives)) {
			// Put this year's month links into a sublist - it breaks the :after css and makes double arrows).
			//$archives_list[] = '<li>' . $yearly_archives[0] . '<ul><li>' . implode( '</li><li>', $monthly_archives ) . '</li></ul></li>';

			// Put this year's link at top of list.
			if ( $include_this_year ) {
				$archives_list[] = '<li>' . $yearly_archives[0] . '</li>';
			}
			// Shift the first element (year) off the list.
			array_shift($yearly_archives);

			// Add this year's monthly links.
			$archives_list[] = '<li>' . implode('</li><li>', $monthly_archives) . '</li>';

		}

		// Append the other years to this array.
		foreach ($yearly_archives as $year_link) {
			if (strlen($year_link)) {
				$archives_list[] = '<li>' . $year_link . '</li>';
			}
		}

		echo '<ul>' . implode('', $archives_list) . '</ul>';

		if ( 'html5' === $format ) {
			echo '</nav>';
		}

		echo $args['after_widget'];
	}


	/**
	 * Handles updating settings for the current Archives widget instance.
	 *
	 * @since 2.8.0
	 *
	 * @param array $new_instance New settings for this instance as input by the user via
	 *                            WP_Widget_Archives::form().
	 * @param array $old_instance Old settings for this instance.
	 * @return array Updated settings to save.
	 */
	public function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$new_instance = wp_parse_args(
			(array) $new_instance,
			array(
				'title' => '',
				'remove_year_suffix' => 0,
				'include_this_year' => 0,
			)
		);
		$instance['title'] = sanitize_text_field( $new_instance['title'] );
		$instance['remove_year_suffix'] = $new_instance['remove_year_suffix'] ? 1 : 0;
		$instance['include_this_year'] = $new_instance['include_this_year'] ? 1 : 0;

		return $instance;
	}


	/**
	 * Outputs the settings form for the Archives widget.
	 *
	 * @since 2.8.0
	 *
	 * @param array $instance Current settings.
	 */
	public function form( $instance ) {
		$instance = wp_parse_args(
			(array) $instance,
			array(
				'title' => '',
				'remove_year_suffix' => 0,
				'include_this_year' => 0,
			)
		);
		?>
		<p>
			<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
			<input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $instance['title'] ); ?>" />
		</p>
		<p>
			<input class="checkbox" type="checkbox"<?php checked( $instance['remove_year_suffix'] ); ?> id="<?php echo $this->get_field_id( 'remove_year_suffix' ); ?>" name="<?php echo $this->get_field_name( 'remove_year_suffix' ); ?>" />
			<label for="<?php echo $this->get_field_id( 'remove_year_suffix' ); ?>"><?php _e( 'Remove current year from month links' ); ?></label>
			<br/>
			<input class="checkbox" type="checkbox"<?php checked( $instance['include_this_year'] ); ?> id="<?php echo $this->get_field_id( 'include_this_year' ); ?>" name="<?php echo $this->get_field_name( 'include_this_year' ); ?>" />
			<label for="<?php echo $this->get_field_id( 'include_this_year' ); ?>"><?php _e( 'Include current year at top of list' ); ?></label>
		</p>
		<?php
	}
}


// Load this widget.
add_action( 'widgets_init', 'taw_load_widgets' );
function taw_load_widgets() {
    register_widget( 'Truncated_Archives_Widget' );
}