custom-decorators

Custom Decorators

Sometimes you might want to re-use some field or type decorator settings. Creating custom decorator might be suitable solution then.

Doing it is quite simple. You'd need to define custom function that returns call to original decorator.

Let's say we want to define custom field decorator that always has String type and requires field description (that originally would be optional)

import { Schema, Query, Field, ObjectType, compileSchema } from 'typegql';

function StringWithDescription(fieldDescription: string) {
  if (!fieldDescription) {
    throw new Error(
      `Field description is required when decorated with @StringWithDescription`,
    );
  }
  return Field({
    type: String,
    description: fieldDescription,
  });
}

Later on, to use such @StringWithDescription field decorator you could simply:

import { ObjectType } from 'typegql';

@ObjectType()
class CustomObject {
  @StringWithDescription('This is custom field') stringValue: string;
}