I have created a custom field type that can store my value in an array.
Everything works fine, however I created another input and pass the value as $field['additional_text'] however this updates ['value'] rather than ['additional_text'].
Array ( [value] => X [additional_text] => Y )
How do I target the correct key to pass the values to?
The solution is when you're creating your fields form inputs the name of the field must be as follows: -
name="<?php echo esc_attr($field['name']) ?>[value_x]"
value="<?php echo esc_attr($field['value']['value_x']) ?>"
name="<?php echo esc_attr($field['name']) ?>[value_y]"
value="<?php echo esc_attr($field['value']['value_y']) ?>"
This will allow you to store multiple values in your custom field type.
You can use ACF's get_field() and update_field() function to get and set the value. You can also manipulate the field with get_post_meta() and update_post_meta() function.
Actually ACF store two values for each meta field. For example if I added 'price' custom field with ACF then 'price' and '_price' 2 post meta fields are created in database. As you know meta_key that has underscore prefix is not listed on edit post page Here real value is saved in 'price' field.
