In case somebody faces the same problems as I did.
For getting the selection field and post its values as meta data:
// Credits: John Heubner
// create a function that will convert this repeater during the acf/save_post action
// priority of 20 to run after ACF is done saving the new values
add_filter('acf/save_post', 'convert_color_to_standard_wp_meta', 20);
function convert_color_to_standard_wp_meta($post_id) {
// pick a new meta_key to hold the values of the color field
// I generally name this field by suffixing _wp to the field name
// as this makes it easy for me to remember this field name
// also note, that this is not an ACF field and will not
// appear when editing posts, it is just a db field that we
// will use for searching
$meta_key = 'watch_functions';
// the next step is to delete any values already stored
// so that we can update it with new values
// and we don't need to worry about removing a value
// when it's deleted from the ACF repeater
delete_post_meta($post_id, $meta_key);
// create an array to hold values that are already added
// this way we won't add the same meta value more than once
// because having the same value to search and filter by
// would be pointless
$saved_values = array();
$functions = get_field('functies');
if(!empty($functions))
{
foreach($functions as $function)
{
// see if this value has already been saved
// note that I am using isset rather than in_array
// the reason for this is that isset is faster than in_array
if (isset($saved_values[$function])) {
// no need to save this one we already have it
continue;
}
// not already save, so add it using add_post_meta()
// note that we are using false for the 4th parameter
// this means that this meta key is not unique
// and can have more then one value
add_post_meta($post_id, $meta_key, $function, false);
// add it to the values we've already saved
$saved_values[$function] = $function;
} // end while have rows
} // end if have rows
} // end function
And quering the database.
$posts = get_posts(array(
'numberposts' => -1,
'post_type' => 'watch',
'posts_per_page' => 100,
'meta_key' => 'score',
'orderby' => 'meta_value',
'order' => 'DESC',
'meta_query' => array(
array(
'relation' => 'AND',
array(
'key' => 'watch_functions',
'compare' => '=',
'compare' => 'calorieenteller',
)
)
),
));
Cheers,
Martijn
