WooCommerce Custom Checkbox Checked by default - php

Question

I am trying to 'check' a checkbox by default in the WooCommerce checkout page.
I'm using the official WooCommerce Checkout Field Editor plugin to add a checkbox but it doesn't give me the ability to have the checkbox 'checked' by default.
I've tried using this code but it's not working:
function custom_override_checkout_fields ( $fields ) {
$fields['additional']['uncheck-to-opt-out-of-our-quarterly-newsletter-neuroscience-matters_field']['default'] = 1;
return $fields;
}
add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );
Any help would be greatly appreciated. Thanks

Answer 1

You should add checkbox on checkout page using below code:
<?php
/**
* Add checkbox field to the checkout
**/
add_action('woocommerce_after_order_notes', 'my_custom_checkout_field');
function my_custom_checkout_field( $checkout ) {
$checked = $checkout->get_value( 'my_checkbox1' ) ? $checkout->get_value( 'my_checkbox1' ) : 1;
echo '<div id="my-new-field"><h3>'.__('My Checkbox: ').'</h3>';
woocommerce_form_field( 'my_checkbox1', array(
'type' => 'checkbox',
'class' => array('input-checkbox'),
'label' => __('I have read and agreed.'),
'required' => true,
), $checked);
echo '</div>';
}

Answer 2

To define the default value of a custom WooCommerce field set up using the woocommerce_checkout_fields hook, it's best to hook another filter function to woocommerce_checkout_get_value or default_checkout_<your_field_name> hooks.
woocommerce_checkout_get_value:
This one is a short circuit filter, which means if you use this, the $value will always start from null and if the returned $value is not null it prevents any attempt to read user's metadata for any previously defined user preferences.
In a sense it is kind of a hard default: for each checkout it uses the value defined in this filter.
add_filter( 'woocommerce_checkout_get_value', 'custom_override_checkout_get_value', 10, 2 );
public function custom_override_checkout_get_value( $value, $field ) {
// $value is null or the result of previous filters
if ( 'uncheck-to-opt-out-of-our-quarterly-newsletter-neuroscience-matters_field' === $field ) {
$value = 1;
}
return $value;
}
default_checkout_<your_field_name>:
This behaves similar to the one above, however this is called after the default value is read from a logged in user's defaults, which may have been set previously as metadata for the given user (e.g. saved during the last checkout if the user has already made a purchase before).
This can be considered a soft default, as with appropriate checks (like below: only set $value if null), the default is only applied if there is no existing user preference.
Also since this uses a dedicated hook name defined by the field name, there's no need to check which field the function is being called for.
add_filter( 'default_checkout_uncheck-to-opt-out-of-our-quarterly-newsletter-neuroscience-matters_field', 'custom_override_default_checkout_field' );
public function custom_override_checkout_get_value( $value ) {
// $value is read from logged in user's meta or null or the result of previous filters
if ( is_null($value) ) {
// Only use default if null, aka. if user has no previous preference saved.
$value = 1;
}
return $value;
}
For more context check out WC_Checkout::get_value() method in wp-content/plugins/woocommerce/includes/class-wc-checkout.php which calls both of these filters.