postgraphile-plugin-foreign-field-direction

This plugin allows you to expose only a single direction of connections exposed by foreign key constraints.

Example

With the following schema

create table classroom (
    id int primary key
);
create table teacher (
    id int primary key,
    classroom_id int not null references classroom(id)
);

in the GraphQL generated, the Teacher type will have a classroomByClassroomId field, and the Classroom type will have a teachersByClassroomId field.

By using the foreignFieldDirection smart tag, you can choose to expose only one of those two fields.

For example, via a smart comment

comment on constraint teacher_classroom_id_fkey on teacher is E'@foreignFieldDirection forward';

Primary Key as Foreign Key Example

With the following schema

create table classroom (
    id int primary key
);
create table classroom_other_info (
    id int primary key references classroom(id)
);

in the GraphQL generated, the Classroom type will have a classroomOtherInfoById field and a classroomOtherInfosById field. Setting the foreign field direction to forward only will omit both these fields on Classroom.

Usage

This is a simple plugin. You can just copy it into your project and modify as needed. You can install it using npm or yarn:

yarn add postgraphile-plugin-foreign-field-direction

const { ForeignFieldDirectionPlugin } = require('postgraphile-plugin-foreign-field-direction')

Smart Tag Arguments

forward and backward are the only valid arguments for the foreignFieldDirection smart tag. Any other value, including a blank value, will set throw an error and prevent the GQL schema from compiling.

The forward argument indicates that you want to expose a traversal only FROM the table on which the constraint is defined.

The backward argument indicates that you want to expose a traversal only TO the table on which the constraint is defined.

Compatibility

This plugin has no dependencies. It was tested with Postgraphile v4.12.9.