Wordpress Customizer keeps hiding custom sections - php

Question

I have custom plugin that adds Customizer sections and options.
The sections can be seen briefly on the customizer screen but then disappear. This behavior is happening on all themes (I am using my plugin on other sites).
Maybe it might be because the setting fields are not used in the theme yet, but even if I create my own theme (for which this plugin is mainly used) and add echo get_theme_mod('setting-key') somewhere in the themes code, the sections are still being hidden by wordpress.
I have clean Wordpress install version 5.2.2, using default Twenty Nineteen theme with only jQuery updater plugin active. I have checked all JS code for potential errors and any hiding happening, but nothing on my part can be causing this.
This is how I am adding sections, in customize_register hook:
add_action('customize_register', 'setup_section');
function setup_section($wp_customize){
// Add section
$wp_customize->add_section('section_id', array(
'title' => 'Section Title',
'priority' => 160,
));
// Add settings for a field
$wp_customize->add_setting('setting_id', array(
'default' => '',
'transport' => 'refresh',
));
// Add the field into a section and assign setting id
$wp_customize->add_control('setting_id', array(
'label' => 'Option Label',
'section' => 'section_id',
'settings' => 'setting_id',
'type' => 'text',
));
}
The PHP code is working as expected, but after the page loads, all my custom sections get display: none; inline css added and the sections disappear.
Any help is appreciated.

Answer 1

Another reason why the custom sections kept hidden is when they don't have any controls. When a section is empty WordPress hides it by default.
Here's a full working piece of code for adding a section within Customizer with one control:
function mytheme_customize_register( $wp_customize ) {
$wp_customize->add_section('footer_settings_section', array(
'title' => 'Footer Text Section'
));
$wp_customize->add_setting('text_setting', array(
'default' => 'Default Text For Footer Section',
));
$wp_customize->add_control('text_setting', array(
'label' => 'Footer Text Here',
'section' => 'footer_settings_section',
'type' => 'textarea',
));
}
add_action( 'customize_register', 'mytheme_customize_register' );