Theme Customizer: issue with default checkbox values

Question

I have a problem with the default value of a checkbox control, in my Theme Customizer. The control has true as default value, but get_theme_mod() always returns me false, when I check that value.

To be precise: if I go to the Theme Customizer and save the value (true or false, it doesn't matter) it starts working correctly. But if I don't manually save the option at least once, I can't retrieve the default value correctly.

Here's my code:

$wp_customize->add_setting(
    'grid_show_cats',
    array(
        'default' => true,
        'sanitize_callback' => 'theme_sanitize_checkbox'
      )
    );

$wp_customize->add_control(
    new Theme_Toggle_Checkbox_Custom_Control(
      $wp_customize,
      'grid_show_cats', array(
          'label' => esc_html__( "Show categories", "theme" ),
          'type' => 'checkbox',
          'settings' => 'grid_show_cats',
          'section' => 'grid'
        )
      )
    );

And this is the custom control declaration, if this may help:

class Theme_Toggle_Checkbox_Custom_Control extends WP_Customize_Control {
        public $type = 'toogle_checkbox';
        public function enqueue(){
            wp_enqueue_style( 'custom_controls_css', get_template_directory_uri() . '/assets/css/custom_controls.css' );
        }
        public function render_content(){
            ?>
            <div class="checkbox_switch">
                <span class="customize-control-title onoffswitch_label"><?php echo esc_html( $this->label ); ?></span>
                <div class="onoffswitch">
                    <input type="checkbox" id="<?php echo esc_attr($this->id); ?>" name="<?php echo esc_attr($this->id); ?>" class="onoffswitch-checkbox" value="<?php echo esc_attr( $this->value() ); ?>" <?php $this->link(); checked( $this->value() ); ?>>
                    <label class="onoffswitch-label" for="<?php echo esc_attr($this->id); ?>"></label>
                </div>
                <p><?php echo wp_kses_post( $this->description ); ?></p>
            </div>
            <?php
        }
    }

Am I missing something?

Thank you.

Answer 1

If you don't add a default value in the get_theme_mod() function by using it's 2nd argument then it will always return false unless that value has changed in the customizer. The solution is simple... ALWAYS use a default value in get_theme_mod.