gatsby-node-custom-schema-printful-products.js

exports.createSchemaCustomization = ({ actions, schema }) => {
    actions.createTypes([
        `
        interface StoreProducts @nodeInterface {
            id: ID!
            productTitle: String
            productId: String
            printfulProduct: PrintfulProduct
            currency: String

        }
    `,
        schema.buildObjectType({
            name: 'StoreProductsMarkdown',
            interfaces: ['Node', 'StoreProducts'],
            extensions: {
                childOf: {
                    type: 'MarkdownRemark',
                },
                infer: true,
            },
            fields: {
                id: 'ID!',
                productTitle: {
                    type: 'String',
                    resolve: (source, _args, context) => {
                        const parent = context.nodeModel.getNodeById({ id: source.parent });

                        return parent.frontmatter.productTitle;
                    },
                },
                productId: {
                    type: 'String',
                    resolve: (source, _args, context) => {
                        const parent = context.nodeModel.getNodeById({ id: source.parent });

                        return parent.frontmatter.productId;
                    },
                },
                printfulProduct: {
                    type: 'PrintfulProduct',
                    resolve: (source, _args, context) => {
                        const parent = context.nodeModel.getNodeById({ id: source.parent });

                        return context.nodeModel
                            .getAllNodes({ type: 'PrintfulProduct' })
                            .find((p) => p.id === parent.frontmatter.productId);
                    },
                },
                currency: {
                    type: 'String',
                    resolve: (_source, _args, context) => {
                        // Currency will always be the same across variants so we can reduce it and move it away from variants and up to product
                        const currencies = context.nodeModel
                            .getAllNodes({ type: 'PrintfulVariant' })
                            .map((variant) => variant.currency);
                        const currency = [...new Set(currencies)].toString();
                        return currency;
                    },
                },
            },
        }),
    ]);
};

exports.onCreateNode = ({ node, actions, createNodeId }) => {
    if (node.internal.type !== 'MarkdownRemark') {
        return;
    }

    actions.createNode({
        id: createNodeId(`StoreProductsMarkdown-${node.id}`),
        parent: node.id,
        internal: {
            type: 'StoreProductsMarkdown',
            contentDigest: node.internal.contentDigest,
        },
    });
};