Question

如何在高级自定义字段中获得与不同帖子类型的双向关系？

我使用此功能，但它不起作用https://www.advancedcustomfields.com/resources/bidirectional-relationships/

我希望获得父类型帖子类型1，其中附加了孩子（帖子类型2）。

Answer 1

您应该尝试一下。其中field_5a67cc16e1169和field_5b7d60a26c7b5是您的自定义字段（只需检查WP管理员中的ACF即可找到您的ID）。

add_filter('acf/update_value/key=field_5a67cc16e1169', 'acf_reciprocal_relationship', 10, 3); //edit this with your ID - field one

add_filter('acf/update_value/key=field_5b7d60a26c7b5', 'acf_reciprocal_relationship', 10, 3); //edit this with your ID - field two

function acf_reciprocal_relationship($value, $post_id, $field) {

    // set the two fields that you want to create
    // a two way relationship for
    // these values can be the same field key
    // if you are using a single relationship field
    // on a single post type

    // the field key of one side of the relationship
    $key_a = 'field_5a67cc16e1169'; //edit this with your ID - field one
    // the field key of the other side of the relationship
    // as noted above, this can be the same as $key_a
    $key_b = 'field_5b7d60a26c7b5'; //edit this with your ID - field two

    // figure out wich side we're doing and set up variables
    // if the keys are the same above then this won't matter
    // $key_a represents the field for the current posts
    // and $key_b represents the field on related posts
    if ($key_a != $field['key']) {
        // this is side b, swap the value
        $temp = $key_a;
        $key_a = $key_b;
        $key_b = $temp;
    }

    // get both fields
    // this gets them by using an acf function
    // that can gets field objects based on field keys
    // we may be getting the same field, but we don't care
    $field_a = acf_get_field($key_a);
    $field_b = acf_get_field($key_b);

    // set the field names to check
    // for each post
    $name_a = $field_a['name'];
    $name_b = $field_b['name'];

    // get the old value from the current post
    // compare it to the new value to see
    // if anything needs to be updated
    // use get_post_meta() to a avoid conflicts
    $old_values = get_post_meta($post_id, $name_a, true);
    // make sure that the value is an array
    if (!is_array($old_values)) {
        if (empty($old_values)) {
            $old_values = array();
        } else {
            $old_values = array($old_values);
        }
    }
    // set new values to $value
    // we don't want to mess with $value
    $new_values = $value;
    // make sure that the value is an array
    if (!is_array($new_values)) {
        if (empty($new_values)) {
            $new_values = array();
        } else {
            $new_values = array($new_values);
        }
    }

    // get differences
    // array_diff returns an array of values from the first
    // array that are not in the second array
    // this gives us lists that need to be added
    // or removed depending on which order we give
    // the arrays in

    // this line is commented out, this line should be used when setting
    // up this filter on a new site. getting values and updating values
    // on every relationship will cause a performance issue you should
    // only use the second line "$add = $new_values" when adding this
    // filter to an existing site and then you should switch to the
    // first line as soon as you get everything updated
    // in either case if you have too many existing relationships
    // checking end updated every one of them will more then likely
    // cause your updates to time out.
    //$add = array_diff($new_values, $old_values);
    $add = $new_values;
    $delete = array_diff($old_values, $new_values);

    // reorder the arrays to prevent possible invalid index errors
    $add = array_values($add);
    $delete = array_values($delete);

    if (!count($add) && !count($delete)) {
        // there are no changes
        // so there's nothing to do
        return $value;
    }

    // do deletes first
    // loop through all of the posts that need to have
    // the recipricol relationship removed
    for ($i=0; $i<count($delete); $i++) {
        $related_values = get_post_meta($delete[$i], $name_b, true);
        if (!is_array($related_values)) {
            if (empty($related_values)) {
                $related_values = array();
            } else {
                $related_values = array($related_values);
            }
        }
        // we use array_diff again
        // this will remove the value without needing to loop
        // through the array and find it
        $related_values = array_diff($related_values, array($post_id));
        // insert the new value
        update_post_meta($delete[$i], $name_b, $related_values);
        // insert the acf key reference, just in case
        update_post_meta($delete[$i], '_'.$name_b, $key_b);
    }

    // do additions, to add $post_id
    for ($i=0; $i<count($add); $i++) {
        $related_values = get_post_meta($add[$i], $name_b, true);
        if (!is_array($related_values)) {
            if (empty($related_values)) {
                $related_values = array();
            } else {
                $related_values = array($related_values);
            }
        }
        if (!in_array($post_id, $related_values)) {
            // add new relationship if it does not exist
            $related_values[] = $post_id;
        }
        // update value
        update_post_meta($add[$i], $name_b, $related_values);
        // insert the acf key reference, just in case
        update_post_meta($add[$i], '_'.$name_b, $key_b);
    }

    return $value;

} // end function acf_reciprocal_relationship

ACF双向关系

1 个答案: