为什么我不能使用 php 将数组项传递到我的函数中？

Question

My items from my array seem to not be passed into the my 'resolve' => function. Right now the function returns fail. If I replace $meta with an array item then it works. Im trying to fetch meta values for GraphQL and dont want to make a function per field.

        add_action( 'graphql_register_types', function() {
            $metas = array('phone', 'city', 'state', 'zip');
            foreach($metas as $meta){
                register_graphql_field( 'Location', $meta, [
                    'type' => 'String',
                    'description' => __( 'The post data', 'wp-graphql' ),
                    'resolve' => function($post, $meta) {
                    $GQL_data = get_post_meta( get_the_ID(), $meta, true);
                    return ! empty( $GQL_data  ) ? $GQL_data  : 'fail';
                    }
                ] );
            }
        });

Expected GraphQL output:

"phone": "123-123-1234",

"city": "Los Angeles",

"state": "CA",

"zip": "99922"

currently all items have a value of: "fail"

Answer 1

This is a callback anonymous function, you cant just change its parameters. What you can use is 'use' like documented here https://secure.php.net/manual/en/functions.anonymous.php

register_graphql_field( 'Location', $meta, [
                    'type' => 'String',
                    'description' => __( 'The post data', 'wp-graphql' ),
                    'resolve' => function($post) use ($meta) {
                    $GQL_data = get_post_meta( get_the_ID(), $meta, true);
                    return ! empty( $GQL_data  ) ? $GQL_data  : 'fail';
                    }
                ] );