ckan-nextjs

ckan-nextjs assumes a "decoupled" approach where the frontend is a separate service from the backend and interacts with backend(s) via an API.

Features

• 🗺️ Unified sites: present data and content in one seamless site, pulling datasets from a DMS (e.g. CKAN) and content from a CMS (e.g. wordpress) with a common internal API.
• 👩‍💻 Developer friendly: built with familiar frontend tech Javascript, React etc
• 🔋 Batteries included: Full set of portal components out of the box e.g. catalog search, dataset showcase, blog etc.
• 🎨 Easy to theme and customize: installable themes, use standard CSS and React+CSS tooling. Add new routes quickly.
• 🧱 Extensible: quickly extend and develop/import your own React components
• 📝 Well documented: full set of documentation plus the documentation of NextJS and Apollo.

For developers

• 🏗 Build with modern, familiar frontend tech such as Javascript and React.
• 🚀 NextJS framework: so everything in NextJS for free React, SSR, static site generation, huge number of examples and integrations etc.
  • SSR => unlimited number of pages, SEO etc whilst still using React.
  • Static Site Generation (SSG) (good for small sites) => ultra-simple deployment, great performance and lighthouse scores etc
• 📋 Typescript support

Getting Started

Setup

Install a recent version of Node. You'll need Node 10.13 or later.

This project uses yarn as the package manager. Install it by running:

npm install -g yarn

Guide

Styling 🎨

We use Tailwind as a CSS framework. Take a look at /styles/index.css to see what we're importing from Tailwind bundle. You can also configure Tailwind using tailwind.config.js file.

Have a look at Next.js support of CSS and ways of writing CSS:

https://nextjs.org/docs/basic-features/built-in-css-support

Backend

So far the app is running with mocked data behind. You can connect CMS and DMS backends easily via environment variables:

$ export DMS=http://ckan:5000
$ export CMS=http://myblog.wordpress.com

Note that we don't yet have implementations for the following CKAN features:

• Activities
• Auth
• Groups
• Facets

Routes

These are the default routes set up in the "starter" app.

• Home /
• Search /search
• Dataset /@org/dataset
• Resource /@org/dataset/r/resource
• Organization /@org
• Collection (aka group in CKAN) (?) - suggest to merge into org
• Static pages, eg, /about etc. from CMS or can do it without external CMS, e.g., in Next.js

New Routes

TODO

Data fetching

We use Apollo client which allows us to query data with GraphQL. We have setup CKAN API for the demo (it uses demo.ckan.org as DMS):

Note that we don't have Apollo Server but we connect CKAN API using apollo-link-rest module. You can see how it works in lib/apolloClient.ts and then have a look at pages/_app.tsx.

For development/debugging purposes, we suggest installing the Chrome extension - https://chrome.google.com/webstore/detail/apollo-client-developer-t/jdkknkkbebbapilgoeccciglkfbmbnfm.

i18n configuration

This is configured by default to support both English and French subpath for language translation. But for subsequent users, this following steps can be used to configure i18n for other languages;

1. Update next.config.js, to add more languages to the i18n locales

i18n: {
  locales: ['en', 'fr', 'nl-NL'], // add more language to the list
  defaultLocale: 'en',  // set the default language to use
},

2. Create a folder for the language in locales --> locales/en-Us

3. In the language folder, different namespace files (json) can be created for each translation. For the index.js use-case, I named it common.json

// locales/en/common.json
{
   "title" : "Portal js in English",
}

// locales/fr/common.json
{
   "title" : "Portal js in French",
}

4. To use on pages using Server-side Props.

import { loadNamespaces } from './_app';
import useTranslation from 'next-translate/useTranslation';

const Home: React.FC = ()=> {
  const { t } = useTranslation();
  return (
    <div>{t(`common:title`)}</div> // we use common and title base on the common.json data
  );
};

export const getServerSideProps: GetServerSideProps = async ({ locale }) => {
      ........  ........
  return {
    props : {
      _ns:  await loadNamespaces(['common'], locale),
    }
  };
};

5. Go to the browser and view the changes using language subpath like this http://localhost:3000 and http://localhost:3000/fr. Note The subpath also activate chrome language Translator

Pre-fetch data in the server-side

When visiting a dataset page, you may want to fetch the dataset metadata in the server-side. To do so, you can use getServerSideProps function from NextJS:

import { GetServerSideProps } from 'next';
import { initializeApollo } from '../lib/apolloClient';
import gql from 'graphql-tag';

const QUERY = gql`
  query dataset($id: String) {
    dataset(id: $id) @rest(type: "Response", path: "package_show?{args}") {
      result
    }
  }
`;

...

export const getServerSideProps: GetServerSideProps = async (context) => {
  const apolloClient = initializeApollo();

  await apolloClient.query({
    query: QUERY,
    variables: {
      id: 'my-dataset'
    },
  });

  return {
    props: {
      initialApolloState: apolloClient.cache.extract(),
    },
  };
};

This would fetch the data from DMS and save it in the Apollo cache so that we can query it again from the components.

Access data from a component

Consider situation when rendering a component for org info on the dataset page. We already have pre-fetched dataset metadata that includes organization property with attributes such as name, title etc. We can now query only organization part for our Org component:

import { useQuery } from '@apollo/react-hooks';
import gql from 'graphql-tag';

export const GET_ORG_QUERY = gql`
  query dataset($id: String) {
    dataset(id: $id) @rest(type: "Response", path: "package_show?{args}") {
      result {
        organization {
          name
          title
          image_url
        }
      }
    }
  }
`;

export default function Org({ variables }) {
  const { loading, error, data } = useQuery(
    GET_ORG_QUERY,
    {
      variables: { id: 'my-dataset' }
    }
  );

  ...

  const { organization } = data.dataset.result;

  return (
    <>
      {organization ? (
        <>
          <img
            src={
              organization.image_url
            }
            className="h-5 w-5 mr-2 inline-block"
          />
          <Link href={`/@${organization.name}`}>
            <a className="font-semibold text-primary underline">
              {organization.title || organization.name}
            </a>
          </Link>
        </>
      ) : (
        ''
      )}
    </>
  );
}

Add a new data source

TODO

Developers

Boot the local instance

Install the dependencies:

yarn # or npm i

Boot the demo portal:

$ yarn dev # or npm run dev

Open http://localhost:3000 to see the home page 🎉

You can start editing the page by modifying /pages/index.tsx. The page auto-updates as you edit the file.

Tests

We use Jest for running tests:

yarn test # or npm run test

# turn on watching
yarn test --watch

We use Cypress tests as well

yarn run e2e

Architecture

• Language: Javascript
• Framework: NextJS - https://nextjs.org/
• Data layer API: GraphQL using Apollo. So controllers access data using GraphQL “gatsby like”

Credits

This is based on a PortalJS example by Datopian.