Prerequisite reference study materials

Development and implementation team

JavaScript ES6, ES7, ES8: Learn to Code on the Bleeding Edge (Full Course)
Full React Course 2020 - Learn Fundamentals, Hooks, Context API, React Router, Custom Hooks

Development team

Frontend Components

Broadly, the frontend components can be categorized as followings:

CLI Tool
Templates
CSS Library
Component Libraries
UI Modules

The CSS Library, Component Libraries, and UI modules are based on templates created by CLI Tool.

Nomenclature

The first line contains the Architecture Component name or info, the second line has npm-package and in the bracket, we have a template based on which the component will be created.

CLI Tool

This tool will be used to bootstrap libraries and micro frontend frameworks for the DIGIT platform. It contains a “template” folder, which will have several starter apps.

The following will be in the template:

Default (WIP) - A default pure js template.
React-component (Done) - Starter template to make the component library based on React.
Module (React based) - Micro frontend framework, which will act as a base for different modules we will create.
… more to come

Features

Easy-to-use CLI
Handles all modern JS features
Bundles commonjs and es module formats
create-react-app for example usage and local dev for React-based libraries
Rollup for bundling
Babel for transpiling
Supports complicated peer-dependencies
Supports CSS modules

Example

Answer some basic prompts about your module, and then the CLI will perform the following steps:

copy over the template
install dependencies via yarn or npm
link packages together for local development
initialize local git repo

Templates

The templates have the following folder structure:

The components related to the template are inside the src folder of the template and an example is created to use and showcase the app created by the template.

Architecture

We have two repos:

digit-ui-internals - https://github.com/egovernments/digit-ui-internals
- Meant for eGov development team to build components and default modules.
- Contains following modules:
  - CSS Library
  - UI Components (presently react-components)
  - Utils Library: Contains Services, Localization handling and React Hooks.
  - UI Modules
    - Core - containing login, routing and global state.
    - PGR
    - FSM
    - PT
    - Payment
digit-ui - https://github.com/egovernments/digit-ui
- Meant for state team to manage, make changes and deploy
- Import digit-ui-internals modules.
- Customizations
  - View
  - Services
- Build and deploy scripts
  - Dockerfile & nginx.conf
  - build-config.yaml

CSS Library

The CSS Library will have all the classes both in the module and compiled form.

Can be imported like

import "@egovernments/digit-ui.css/Button"

or like this for full CSS import

import "@egovernments/digit-ui.css"

Component Libraries

Component Library will have the set of all the required components defined in them.

# Atoms
<egov-button text action />

<egov-checkbox name value />

<egov-textarea placeholder />

# Molecules
<egov-list data>
  <egov-list-item />
</egov-list>

<egov-searchbox placeholder action />

<egov-list-filter>
  <egov-input />
  <egov-list data />
</egov-list-filter>

Utils Library

This will have the followings:

Workflows
API handling - API caching and handling strategies will be here, imported, and shared by all modules. Published as a function, can be used by anyone.

import { fetchAPI } from '@egovernments/digit-utils'

async function searchProperty() {
  const { data, error } = await fetchAPI("/api/searchProperty");
  if (error) return "";
  return data;
}

Internationalization (i18n)

<egov-textarea placeholder="i18n.PGR_NEW_COMMENTS" />

getConfig
- This will be like MDMS config service
- The default and state configs will be stored on GitHub.
- getConfig will fetch the latest config on runtime and initiate the module.

default config:

{
  "name": "create_complaint",
  "action": "createComplaint",
  "init": "newComplaintInit",
  "saveUrl": "/rainmaker-pgr/v1/requests/_create",
  "redirectionRoute":"/complaint-submitted",
  "fields": [{
    "id": "city",
    "name": "city",
    "type": "dropdown",
    "labelText": "{{i18n.CORE_COMMON_CITY}}",
    "hintText": "{{i18n.CS_CREATECOMPLAINT_SELECT_PLACEHOLDER}}",
    "errMessage": "{{i18n.CS_ADDCOMPLAINT_COMPLAINT_TYPE_PLACEHOLDER}}",
    "required": true,
    "action": "createComplaint.updateDependentFields"
  }, {
    "id": "address",
    "name": "address",
    "type": "input-textarea",
    "labelText": "{{i18n.CS_ADDCOMPLAINT_LOCATION}}",
    "hintText": "{{i18n.CS_COMPLAINT_DETAILS_LOCATION}}",
    "errMessage": "",
    "action": ""
  }, {
    "id": "media",
    "name": "media",
    "type": "input-file",
    "errMessage": "{{i18n.CS_FILE_UPLOAD_FAILED}}",
    "action": ""
  }],
  "buttons": [{
    "id": "addComplaint-submit-complaint",
    "name": "submit",
    "labelText": "{{i18n.CS_ADDCOMPLAINT_ADDITIONAL_DETAILS_SUBMIT_COMPLAINT}}",
    "action": "createComplaint.submit"
  }]
}

state config:

{
  "name": "create_complaint",
  "redirectionRoute":"__delete__",
  "saveUrl": "__delete__",
  "fields": [{
    "__action__": "insert_after",
    "__property__": "address",
    "id": "landmark",
    "name": "landmark",
    "type": "input-text",
    "labelText": "{{i18n.CS_ADDCOMPLAINT_LANDMARK}}",
    "hintText": "{{i18n.CS_ADDCOMPLAINT_LANDMARK_PLACEHOLDER}}",
    "errMessage": "{{i18n.PT_LANDMARK_ERROR_MESSAGE}}",
    "action": "",
  }, {
    "__action__": "update",
    "id": "address",
    "labelText": "{{i18n.CS_ADDCOMPLAINT_LOCATION}}",
    "hintText": "{{i18n.CS_COMPLAINT_DETAILS_LOCATION}}",
  }]
}

getConfig:

# @egovernments/digit-utils
exports.getConfig = async (state, module = "", screen = "") => {
  let path = state;
  if (module) {
    path = `${path}.${module}`;
    if (screen) {
      path = `${path}.${screen}`
    }
  }
  const { data, error } = await fetchAPI(`/api/_get?config=${path}`)
  if (error) return {};
  return data;
}

# Module
import { getConfig } from '@egovernments/digit-utils'

const compaintConfig = getConfig("pb", "pgr", "create_complaint");

Modules

The module will be a black box for the states, they will only access throw node_modules or CDN. Any state-specific components can be passed during the initialization of the module inside the state’s employee or citizen app.

The modules structure will look like:

The module code is in src and an example is created to show how it will be imported in the core app and can be modified at the state level.

The components passed to the module from the core app are:

components (optional): Any custom component that is created outside of module scope.
onRouteChange: This is a callback function that will be called by the module itself to alert the core app about the route changes so the sidebar handler can change the active item.
theme (optional): This is a set of CSS variables which states can modify to change the theme of the module.

Eg, PGRModule:

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-rdux';
import { getConfig } from '@egovernments/digit-utils';

import configureStore from './store';
import applyTheme from "./utils/theme";

import PGRApp from './App';

const PGRModule = ({ config, components, onRouteChange, theme }) => {
  applyTheme(theme);
  return <Provider store={configureStore(config)}>
    <PGRApp components={components} onRouteChange={onRouteChange} />
  </Provider>
}

function initPGR = ({ state, element, components, onRouteChange, theme = {} }) => {
  getConfig(state, "pgr").then(config => {
    ReactDOM.render(
      <PGRModule config={config}
        components={PGRComponents}
        onRouteChange={onRouteChange} theme={theme} />,
      document.getElementById(element));
  })
}

export default initPGR

Modules will have the followings inbuilt

Theme - this may change if we later decide to use any css-in-js library, like styled-components.
Components
Routes
State management
Business logic
API integrations

Employee / Citizen App

The app will import the developed module.

import './index.css'

import { initPGR } from '@egovernments/pgr-module';
import punjabLogo from './assets/logo.png'

const theme = {
  "--primary-color": "#3f51b5",
  "--text-color": "#212121"
}

const PGRComponents = {
  "logo": punjabLogo
}

const initPunjabPGR = (onRouteChange) =>
  initPGR({
    state: "pb",
    element: "#appWrapper",
    components: PGRComponents,
    onRouteChange, theme
  });

export default initPunjabPGR;

Another method will be importing from CDN:

import './index.css'
import punjabLogo from './assets/logo.png'

const theme = {
  "--primary-color": "#3f51b5",
  "--text-color": "#212121"
}

const PGRComponents = {
  "logo": punjabLogo
}

const initPunjabPGR = (onRouteChange) => {
  import("https://unpkg.com/@egovernments/pgr-module").then(({ initPGR }) => {
    initPGR({
      state: "pb",
      element: "#appWrapper",
      components: PGRComponents,
      onRouteChange, theme
    })
  })
}
export default initPunjabPGR;

At the next phase, the Employee and Citizen app can be rewritten to be a single app with role and permissions based rendering.

Frontend Architecture Design