Basic CRUD Interface

Summary

This project implements a basic CRUD interface for a set of Users with the following properties:

• firstName
• middleName
• lastName
• suffix
• dateOfBirth
• gender
• phoneNumber
• streetAddress
• city
• state
• zipCode

One of the major goals of this project is to have all data (i.e. the set of users) be stored in a local JavaScript object, develop the entire interface, then at a later time move the data to remote storage such as a SQL database or NoSQL database without the need to modify the files implementing the interface.

In this project, the interface is implemented in Angular (i.e. version 2+), so files that should not need to be modified include the Angular component TypeScript files and any referenced HTML and CSS files. The data will be fetched from an Angular service, so the only changes required to fetch the data from a remote server should be to the file implementing this service.

Via the interface, you should be able to:

1. Fetch and display a list of users, given begin and end indexes
2. Fetch and display information for a specific user, given a user's id number
3. Add a new user
4. Modify a given user's information
5. Delete a user

Each user will be assigned a unique id number when added. Although we will use unique integers, it should be possible to use any number or character string as a unique identifier, e.g. a GUID. We assume that users are kept in an ordered list, even if not explicitly, so that we can ask for the first 10 users, the second 10 users, etc.

Furthermore, we will be utilizing these technologies:

1. Material Design for styling.

2. The interface should be useable not only on computer screens, but also on a tablet or smart phone. Here Material Design Lite will also provide this functionality. During development, you should test the interface on all 3 types of devices.

3. Falcor will be used to implement the data source, including a library named falcor-local-datasource to enable keeping the data local for this project.

This README file will consist of a series of sections, each describing a logical step in the development process. We hope that this file can then function as a tutorial for developing similar CRUD interfaces.

Setup

If you plan to use this project for development, you will need to be sure that the following are installed:

1. Git (https://git-scm.com/)
2. Node.js (https://nodejs.org/)
3. Typescript: npm install -g typescript
4. Angular CLI: npm install -g @angular/cli

NOTE: To initially create this project, I used the command ng new basic-crud. When I tried to fire up the web site using ng serve, I got the message "Error: Cannot find module '@angular-devkit/core'". However, after installing that package with npm install @angular-devkit/core --save I was able to fire up the web site.

You may simply clone this project and proceed from there, but if you decide to create this project from scratch, you should create the project using the ng new <project-name> command, then execute these commands to install needed packages locally in the project:

• `npm install @angular/material @angular/cdk @angular/animations hammerjs --save
• npm install falcor falcor-local-datasource @types/falcor --save

I, personally, dislike Angular's indentation scheme and much prefer using TAB characters for indentation. So, I "fix up" the following files:

src/index.html
src/main.ts
src/test.ts
src/app/app.module.ts
src/app/app.component.ts
src/app/app.component.html
src/app/app.component.spec.ts

You should get in the habit of firing up the web site and testing it in a browser often, e.g. after modifying the above files. The sooner you detect a problem, the more likely you'll be able to quickly find and fix it.

Angular CLI makes it easy for you to create new objects, including services, classes, components, etc. However, files will be created using Angular's formatting style, and if you don't like that, you will have to modify the template files used to create those source files. Here are some files that I prefer to edit before using Angular CLI to create new objects:

node_modules/@schematics/angular/service/files/__path__/__name@dasherize__.service.ts
node_modules/@schematics/angular/service/files/__path__/__name@dasherize__.service.spec.ts

The location of these files might change - Google has no approved procedure for editing these templates yet. But as of Angular CLI 1.6.7, this is where the templates are located (you can find your version of Angular CLI via the command ng -v). You can find similar templates for other Angular CLI objects by replacing 'service' in the paths above with, e.g. 'component'.

A quick test of your setup

At this point you should be able to fire up the server and view the web site. Before you do, however, make one additional change. Modify the src/app/app.component.html file and test the web server. Change that file to have these contents:

<div style="text-align:center">
	<h1>
		Welcome to Basic CRUD!
	</h1>
</div>

After saving that file, if you execute the command ng serve and point your web browser to http://localhost:4200 you should see the following:

Using Material Design

In order to utilize the Material Design components, you will need to make the following changes to some of the source files:

1. In src/app/app.module.ts:

   • add import {BrowserAnimationsModule} from '@angular/platform-browser/animations';
   • add import {MatButtonModule, MatTableModule} from '@angular/material';
   • add BrowserAnimationsModule, MatButtonModule and MatTableModule to the list of imports
   • if you want to use any other 'Mat' modules, import them as above

2. In src/styles.css:

   • add @import "~@angular/material/prebuilt-themes/indigo-pink.css";

3. In src/main.ts:

   • add import 'hammerjs';

4. In src/index.html:

   • add <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">

After you make the above changes, your web site should look almost the same, except that the font used will now be a sans-serif font:

Displaying a list of users

Before we even implement the data model, we'll display a hard coded list of users, which will illustrate the use of Material Design Lite and show what the interface will look like. To do that we will use the Material Design mat-table component. Modify the following files as shown:

File src/app/app.component.css

.limit-width {
	max-width: 640px;
	margin-left: auto;
	margin-right: auto;
	}

File src/app/app.component.ts

import {Component, OnInit} from '@angular/core';

@Component({
	selector: 'app-root',
	templateUrl: './app.component.html',
	styleUrls: ['./app.component.css']
	})

export class AppComponent implements OnInit {

lUsers: any[] = [];
columnsToDisplay = ['firstName', 'lastName', 'gender', 'dateOfBirth'];

// --------------------------------------------------------------------------

ngOnInit() {

this.addUser('Dana',    'Cox',      'M',  'Jan  5, 1988');
this.addUser('John',    'Deighan',  'M',  'Feb 12, 1953');
this.addUser('Lewis',   'Foster',   'M',  'Aug  3, 1983');
this.addUser('Arathi',  'Prasad',   'F',  'Sep 23, 1973');
} // ngOnInit()

// --------------------------------------------------------------------------

addUser(fName, lName, gen, dob) {

this.lUsers.push({
	firstName: fName,
	lastName: lName,
	gender: gen,
	dateOfBirth: dob
	});
} // addUser()

// --------------------------------------------------------------------------

getUsers() {

return this.lUsers;
} // getUsers()

// --------------------------------------------------------------------------

} // class AppComponent

File src/app/app.component.html

<div class="mat-elevation-z8">

	<mat-table [dataSource]="getUsers()" class="limit-width">

		<!-- First Name Column -->
		<ng-container matColumnDef="firstName">
			<mat-header-cell *matHeaderCellDef> First Name </mat-header-cell>
			<mat-cell *matCellDef="let user"> {{user.firstName}} </mat-cell>
		</ng-container>

		<!-- Last Name Column -->
		<ng-container matColumnDef="lastName">
			<mat-header-cell *matHeaderCellDef> Last Name </mat-header-cell>
			<mat-cell *matCellDef="let user"> {{user.lastName}} </mat-cell>
		</ng-container>

		<!-- Gender Column -->
		<ng-container matColumnDef="gender">
			<mat-header-cell *matHeaderCellDef> Gender </mat-header-cell>
			<mat-cell *matCellDef="let user"> {{user.gender}} </mat-cell>
		</ng-container>

		<!-- Date of Birth Column -->
		<ng-container matColumnDef="dateOfBirth">
			<mat-header-cell *matHeaderCellDef> Date of Birth </mat-header-cell>
			<mat-cell *matCellDef="let user"> {{user.dateOfBirth}} </mat-cell>
		</ng-container>

		<mat-header-row *matHeaderRowDef="columnsToDisplay"></mat-header-row>
		<mat-row *matRowDef="let myRowData; columns: columnsToDisplay"></mat-row>

	</mat-table>

</div>

Adding a service implementing a falcor Model

To create a new service, which we will use to supply data to the views, i.e. Angular components, execute the command (from inside your project's folder):

ng generate service falcor-model

You should find that the following 2 files were created:

src/app/falcor-model.service.spec.ts
src/app/falcor-model.service.ts