Add bebug mode flag.

Output it for JS to use.

inc/class-advent-calendar-settings-page.php

@@ -89,6 +89,14 @@ class Advent_Calendar_Settings_Page {
 			'cac_settings_name_section'
 		);
 
+		add_settings_field(
+			'cac-debug_mode',
+			__( 'debug mode?', 'codeup-advent-calendar' ),
+			[ $this, 'render_cac_debug_mode_checkbox_field' ],
+			'cac_settings_name',
+			'cac_settings_name_section'
+		);
+
 		add_settings_field(
 			'cac-create_days_checkbox',
 			__( 'Create default days?', 'codeup-advent-calendar' ),
@@ -172,6 +180,19 @@ class Advent_Calendar_Settings_Page {
 		echo '<p class="description">' . __( 'Checking the second box will DELETE any existing days', 'codeup-advent-calendar' ) . '</p>';
 	}
 
+	/**
+	 * Render the debug mode check box.
+	 */
+	function render_cac_debug_mode_checkbox_field() {
+		// Get current value.
+		$options       = get_option( 'cac_settings_name' );
+		$current_value = isset( $options['cac-debug_mode'] ) ? $options['cac-debug_mode'] : '';
+
+		echo '<input type="checkbox" name="cac_settings_name[cac-debug_mode]" class="cac-debug_mode_checkbox_field" value="1" ' . checked($current_value, true, false ) . '" > ' .
+		     __( 'debug on', 'codeup-advent-calendar' ) . '<br>';
+		echo '<p class="description">' . __( 'Checking this will allow you to click all days on the calendar', 'codeup-advent-calendar' ) . '</p>';
+	}
+
 	/**
 	 * Validate input and convert to comma separated list.
 	 *

templates/archive-advent_day.php

@@ -27,6 +27,7 @@ wp_enqueue_style(
 /* get our calendar options */
 $options = get_option( 'cac_settings_name' );
 $page_title       = isset( $options['cac-calendar_title'] ) ? $options['cac-calendar_title'] : '';
+$cac_debug_mode       = isset( $options['cac-debug_mode'] ) ? $options['cac-debug_mode'] : '';
 $image_id = isset( $options['cac-calendar_background_id'] ) ? intval( $options['cac-calendar_background_id'] ) : 0;
 $background_image = wp_get_attachment_image_src( $image_id, 'full' );
 
@@ -60,7 +61,7 @@ wp_enqueue_script(
 
 wp_localize_script( 'advent-calendar', 'advent_calendar_data',
 	[
-		'foo' => 'bar',
+		'debug_mode' => $cac_debug_mode ?? '0',
 	]
 );