Flatten Strapi4 Api Responses

flatten-response.js

// ./src/middlewares/flatten-response.js

const strapiFlatten = (data) => {
  const isObject = (data) => Object.prototype.toString.call(data) === '[object Object]';
  const isArray = (data) => Object.prototype.toString.call(data) === '[object Array]';

  const flatten = (data) => {
    if (!data.attributes) return data;

    return {
      id: data.id,
      ...data.attributes,
    };
  };

  if (isArray(data)) {
    return data.map((item) => strapiFlatten(item));
  }

  if (isObject(data)) {
    if (isArray(data.data)) {
      data = [...data.data];
    } else if (isObject(data.data)) {
      data = flatten({ ...data.data });
    } else if (data.data === null) {
      data = null;
    } else {
      data = flatten(data);
    }

    for (const key in data) {
      data[key] = strapiFlatten(data[key]);
    }

    return data;
  }

  return data;
};

async function respond(ctx, next) {
  await next();
  if (!ctx.url.startsWith("/api")) {
    return;
  }

  if (ctx.response.body)
    return ctx.response.body = {
      data: strapiFlatten(ctx.response.body.data),
      meta: ctx.response.body.meta,
    };

  return ctx.response.body = {
    data: null,
    error: { message: 'Not found' },
  };
}

module.exports = () => respond;

middlewares.js

// ./config/middlewares.js

module.exports = [
  // ...
  "strapi::body",
  'global::flatten-response', // <-- Add this line to integrate the new middleware function
  "strapi::session",
  // ...
];