gatsby-source-prismic/src/builders/buildImageFieldConfig.ts

Gatsby source plugin for building websites using Prismic as a data source

import * as prismicT from "@prismicio/types";
import * as RTE from "fp-ts/ReaderTaskEither";
import * as R from "fp-ts/Record";
import * as ReadonlyA from "fp-ts/ReadonlyArray";
import * as S from "fp-ts/Semigroup";
import { pipe } from "fp-ts/function";

import { buildObjectType } from "../lib/buildObjectType";
import { getTypeName } from "../lib/getTypeName";
import { createType } from "../lib/createType";

import { buildImageBaseFieldConfigMap } from "./buildImageBaseFieldConfigMap";

import { Dependencies, FieldConfigCreator } from "../types";

/**
 * Creates a GraphQL type containing fields for thumbnails of an Image field.
 *
 * @param path - Path to the field.
 * @param schema - Schema definition for the field.
 *
 * @returns GraphQL type name for the created type.
 */
// TODO: Move `fields` typename to Dependencies (create in `buildDependencies.ts`).
const createThumbnailsType = (
	path: string[],
	// schema: PrismicSchemaImageField,
	schema: prismicT.CustomTypeModelImageField,
): RTE.ReaderTaskEither<Dependencies, never, string> =>
	pipe(
		RTE.ask<Dependencies>(),
		RTE.bind("thumbnails", () => RTE.right(schema.config?.thumbnails ?? [])),
		RTE.bind("fields", (scope) =>
			pipe(
				R.fromFoldableMap(
					S.last<prismicT.CustomTypeModelImageThumbnail>(),
					ReadonlyA.Foldable,
				)(scope.thumbnails, (thumbnail) => [thumbnail.name, thumbnail]),
				R.map(() => scope.nodeHelpers.createTypeName("ImageThumbnailType")),
				(fields) => RTE.right(fields),
			),
		),
		RTE.chain((scope) =>
			buildObjectType({
				name: scope.nodeHelpers.createTypeName([
					...path,
					"ImageThumbnailsType",
				]),
				fields: scope.fields,
			}),
		),
		RTE.chainFirst(createType),
		RTE.map(getTypeName),
	);

/**
 * Builds a GraphQL field configuration object for an Image Custom Type field.
 * If the field is configured to have thumbnails, a field-specific type is
 * created for them.
 *
 * This function registers a typepath for the field.
 *
 * @param path - Path to the field.
 * @param schema - Schema definition for the field.
 *
 * @returns GraphQL field configuration object.
 */
export const buildImageFieldConfig: FieldConfigCreator<
	prismicT.CustomTypeModelImageField
> = (path, schema) =>
	pipe(
		RTE.ask<Dependencies>(),
		RTE.bind("thumbnailsTypeName", () =>
			ReadonlyA.isEmpty(schema.config?.thumbnails ?? [])
				? RTE.right(undefined)
				: createThumbnailsType(path, schema),
		),
		RTE.bind("baseFields", () => buildImageBaseFieldConfigMap),
		RTE.chain((scope) =>
			buildObjectType({
				name: scope.nodeHelpers.createTypeName([...path, "ImageType"]),
				fields: scope.thumbnailsTypeName
					? {
							...scope.baseFields,
							thumbnails: {
								type: scope.thumbnailsTypeName,
								resolve: (source: prismicT.ImageField) => source,
							},
					  }
					: scope.baseFields,
			}),
		),
		RTE.chainFirst(createType),
		RTE.map(getTypeName),
	);