In this tutorial, we will go to the walkthrough of building GraphQL query language API for communication between Node-Express-MongoDB on Server side and Angular 7 on the Client side.

The comprehensive step by step tutorial on building CRUD (Create, Read, Update, Delete) Web Application using Node.js, Express.js, Angular 7, MongoDB and GraphQL. This is our first tutorial that using GraphQL, you can find more reference and guide on their official site.

On the server side, we are using Express-Graphql modules and it’s dependencies. For the client side, we are using Apollo Angular modules and dependencies.

Table of Contents:

• Create Express.js App
• Install and Configure Mongoose.js Modules for Accessing MongoDB
• Create Mongoose.js Model for the Book Document
• Install GraphQL Modules and Dependencies
• Create GraphQL Schemas for the Book
• Add Mutation for CRUD Operation to the Schema
• Test GraphQL using GraphiQL
• Create Angular 7 Application
• Install and Configure Required Modules and Dependencies
• Create Routes for Navigation between Angular Pages/Component
• Display List of Books using Angular 7 Material
• Show and Delete Books
• Add a New Book using Angular 7 Material
• Edit a Book using Angular 7 Material
• Run and Test GraphQL CRUD from the Angular 7 Application

The following tools, frameworks, and modules are required for this tutorial:

• Node.js (choose recommended version)
• Angular 7 CLI
• Angular 7
• Express.js
• GraphQL
• Express-GraphQL
• Apollo Angular
• Terminal (Mac/Linux) or Node Command Line (Windows)
• IDE or Text Editor (We are using Atom)

We assume that you have installed Node.js. Now, we need to check the Node.js and NPM versions. Open the terminal or Node command line then type this commands.

node -v
v8.12.0
npm -v
6.4.1

That’s the Node.js and NPM version that we are using. Now, you can go to the main steps.

1. Create Express.js App

If Express.js Generator hasn’t installed, type this command from the terminal or Node.js command prompt.

sudo npm install express-generator -g

The sudo keyword is using in OSX or Linux Terminal otherwise you can use that command without sudo. Before we create an Express.js app, we have to create a root project folder inside your projects folder. From the terminal or Node.js command prompt, type this command at your projects folder.

mkdir node-graphql

Go to the newly created directory.

cd ./node-graphql

From there, type this command to generate Express.js application.

express server

Go to the newly created Express.js app folder.

cd ./server

Type this command to install all required NPM modules that describe in package.json dependencies.

npm install

To check the Express.js app running smoothly, type this command.

nodemon

or

npm start

If you see this information in the terminal or command prompt that means your Express.js app is ready to use.

[nodemon] 1.18.6
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node ./bin/www`

2. Install and Configure Mongoose.js Modules for Accessing MongoDB

To install Mongoose.js and it’s required dependencies, type this command.

npm install mongoose bluebird --save

Next, open and edit app.js then declare the Mongoose module.

var mongoose = require('mongoose');

Create a connection to the MongoDB server using this lines of codes.

mongoose.connect('mongodb://localhost/node-graphql', { promiseLibrary: require('bluebird'), useNewUrlParser: true })
  .then(() =>  console.log('connection successful'))
  .catch((err) => console.error(err));

Now, if you re-run again Express.js server after running MongoDB server or daemon, you will see this information in the console.

[nodemon] 1.18.6
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node ./bin/www`
connection successful

That’s mean, the connection to the MongoDB is successful.

3. Create Mongoose.js Model for the Book Document

Before creating a Mongoose.js model that represent Book Document, we have to create a folder at the server folder for hold Models. After that, we can create a Mongoose.js model file.

mkdir models
touch models/Book.js

Open and edit server/models/Book.js then add these lines of codes.

var mongoose = require('mongoose');

var BookSchema = new mongoose.Schema({
  id: String,
  isbn: String,
  title: String,
  author: String,
  description: String,
  published_year: { type: Number, min: 1945, max: 2019 },
  publisher: String,
  updated_date: { type: Date, default: Date.now },
});

module.exports = mongoose.model('Book', BookSchema);

4. Install GraphQL Modules and Dependencies

Now, the GraphQL time. Type this command to install GraphQL modules and it’s dependencies.

npm install express express-graphql graphql cors --save

Next, open and edit server/app.js then declare all of those modules and dependencies.

var graphqlHTTP = require('express-graphql');
var schema = require('./graphql/bookSchema');
var cors = require("cors");

The schema is not created yet, we will create it in the next steps. Next, add these lines of codes for configuring GraphQL that can use over HTTP.

app.use('*', cors());
app.use('/graphql', cors(), graphqlHTTP({
  schema: schema,
  rootValue: global,
  graphiql: true,
}));

That’s configuration are enabled CORS and the GraphiQL. GraphiQL is the user interface for testing GraphQL query.

5. Create GraphQL Schemas for the Book

Create a folder at the server folder for hold GraphQL Schema files then create a Javascript file for the schema.

mkdir graphql
touch graphql/bookSchemas.js

Next, open and edit server/graphql/bookSchemas.js then declares all required modules and models.

var GraphQLSchema = require('graphql').GraphQLSchema;
var GraphQLObjectType = require('graphql').GraphQLObjectType;
var GraphQLList = require('graphql').GraphQLList;
var GraphQLObjectType = require('graphql').GraphQLObjectType;
var GraphQLNonNull = require('graphql').GraphQLNonNull;
var GraphQLID = require('graphql').GraphQLID;
var GraphQLString = require('graphql').GraphQLString;
var GraphQLInt = require('graphql').GraphQLInt;
var GraphQLDate = require('graphql-date');
var BookModel = require('../models/Book');

Create a GraphQL Object Type for Book models.

var bookType = new GraphQLObjectType({
  name: 'book',
  fields: function () {
    return {
      _id: {
        type: GraphQLString
      },
      isbn: {
        type: GraphQLString
      },
      title: {
        type: GraphQLString
      },
      author: {
        type: GraphQLString
      },
      description: {
        type: GraphQLString
      },
      published_year: {
        type: GraphQLInt
      },
      publisher: {
        type: GraphQLString
      },
      updated_date: {
        type: GraphQLDate
      }
    }
  }
});

Next, create a GraphQL query type that calls a list of book and single book by ID.

var queryType = new GraphQLObjectType({
  name: 'Query',
  fields: function () {
    return {
      books: {
        type: new GraphQLList(bookType),
        resolve: function () {
          const books = BookModel.find().exec()
          if (!books) {
            throw new Error('Error')
          }
          return books
        }
      },
      book: {
        type: bookType,
        args: {
          id: {
            name: '_id',
            type: GraphQLString
          }
        },
        resolve: function (root, params) {
          const bookDetails = BookModel.findById(params.id).exec()
          if (!bookDetails) {
            throw new Error('Error')
          }
          return bookDetails
        }
      }
    }
  }
});

Finally, exports this file as GraphQL schema by adding this line at the end of the file.

module.exports = new GraphQLSchema({query: queryType});

6. Add Mutation for CRUD Operation to the Schema

For completing CRUD (Create, Read, Update, Delete) operation of the GraphQL, we need to add a mutation that contains create, update and delete operations. Open and edit server/graphql/bookSchemas.js then add this mutation as GraphQL Object Type.

var mutation = new GraphQLObjectType({
  name: 'Mutation',
  fields: function () {
    return {
      addBook: {
        type: bookType,
        args: {
          isbn: {
            type: new GraphQLNonNull(GraphQLString)
          },
          title: {
            type: new GraphQLNonNull(GraphQLString)
          },
          author: {
            type: new GraphQLNonNull(GraphQLString)
          },
          description: {
            type: new GraphQLNonNull(GraphQLString)
          },
          published_year: {
            type: new GraphQLNonNull(GraphQLInt)
          },
          publisher: {
            type: new GraphQLNonNull(GraphQLString)
          }
        },
        resolve: function (root, params) {
          const bookModel = new BookModel(params);
          const newBook = bookModel.save();
          if (!newBook) {
            throw new Error('Error');
          }
          return newBook
        }
      },
      updateBook: {
        type: bookType,
        args: {
          id: {
            name: 'id',
            type: new GraphQLNonNull(GraphQLString)
          },
          isbn: {
            type: new GraphQLNonNull(GraphQLString)
          },
          title: {
            type: new GraphQLNonNull(GraphQLString)
          },
          author: {
            type: new GraphQLNonNull(GraphQLString)
          },
          description: {
            type: new GraphQLNonNull(GraphQLString)
          },
          published_year: {
            type: new GraphQLNonNull(GraphQLInt)
          },
          publisher: {
            type: new GraphQLNonNull(GraphQLString)
          }
        },
        resolve(root, params) {
          return BookModel.findByIdAndUpdate(params.id, { isbn: params.isbn, title: params.title, author: params.author, description: params.description, published_year: params.published_year, publisher: params.publisher, updated_date: new Date() }, function (err) {
            if (err) return next(err);
          });
        }
      },
      removeBook: {
        type: bookType,
        args: {
          id: {
            type: new GraphQLNonNull(GraphQLString)
          }
        },
        resolve(root, params) {
          const remBook = BookModel.findByIdAndRemove(params.id).exec();
          if (!remBook) {
            throw new Error('Error')
          }
          return remBook;
        }
      }
    }
  }
});

Finally, add this mutation to the GraphQL Schema exports.

module.exports = new GraphQLSchema({query: queryType, mutation: mutation});

7. Test GraphQL using GraphiQL

To test the queries and mutations of CRUD operations, re-run again the Express.js app then open the browser. Go to this address <a href="http://localhost:3000/graphql" target="_blank">http://localhost:3000/graphql</a> to open the GraphiQL User Interface.

To get the list of books, replace all of the text on the left pane with this GraphQL query then click the Play button.

To get a single book by ID, use this GraphQL query.

{
  book(id: "5c738dd4cb720f79497de85c") {
    _id
    isbn
    title
    author
    description
    published_year
    publisher
    updated_date
  }
}

To add a book, use this GraphQL mutation.

mutation {
  addBook(
    isbn: "12345678",
    title: "Whatever this Book Title",
    author: "Mr. Bean",
    description: "The short explanation of this Book",
    publisher: "Djamware Press",
    published_year: 2019
  ) {
    updated_date
  }
}

You will the response at the right pane like this.

{
  "data": {
    "addBook": {
      "updated_date": "2019-02-26T13:55:39.160Z"
    }
  }
}

To update a book, use this GraphQL mutation.

mutation {
  updateBook(
    id: "5c75455b146dbc2504b94012",
    isbn: "12345678221",
    title: "The Learning Curve of GraphQL",
    author: "Didin J.",
    description: "The short explanation of this Book",
    publisher: "Djamware Press",
    published_year: 2019
  ) {
    _id,
    updated_date
  }
}

You will see the response in the right pane like this.

{
  "data": {
    "updateBook": {
      "_id": "5c75455b146dbc2504b94012",
      "updated_date": "2019-02-26T13:58:35.811Z"
    }
  }
}

To delete a book by ID, use this GraphQL mutation.

mutation {
  removeBook(id: "5c75455b146dbc2504b94012") {
    _id
  }
}

You will see the response in the right pane like this.

{
  "data": {
    "removeBook": {
      "_id": "5c75455b146dbc2504b94012"
    }
  }
}

8. Create Angular 7 Application

Before creating an Angular 7 application, we have to install Angular 7 CLI first. Type this command to install it.

sudo npm install -g @angular/cli

Next, create a new Angular 7 Web Application using this Angular CLI command at the root of this project folder.

ng new client

If you get the question like below, choose Yes and SCSS (or whatever you like to choose).

? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? SCSS

Next, go to the newly created Angular 7 project folder.

cd client

Type this command to run the Angular 7 application using this command.

ng serve

Open your browser then go to this address localhost:4200 to check if Angular 7 created successfully.

9. Install and Configure Required Modules and Dependencies

Now, we have to install and configure all of the required modules and dependencies. Type this command to install the modules.

npm install --save apollo-angular apollo-angular-link-http apollo-link apollo-client apollo-cache-inmemory graphql-tag graphql

Next, open and edit client/src/app/app.module.ts then add these imports.

import { HttpClientModule } from '@angular/common/http';
import { ApolloModule, Apollo } from 'apollo-angular';
import { HttpLinkModule, HttpLink } from 'apollo-angular-link-http';

Add these modules to the @NgModule imports.

imports: [
  ...,
  HttpClientModule,
  ApolloModule,
  HttpLinkModule,
  ...
],

Create a constructor inside class AppModule then inject above modules and create a connection to the GraphQL in the Express.js server.

export class AppModule {
  constructor(
    apollo: Apollo,
    httpLink: HttpLink
  ) {
     apollo.create({
      link: httpLink.create({ uri: 'http://localhost:3000/graphql'}),
      cache: new InMemoryCache()
    });
  }
}

10. Create Routes for Navigation between Angular Pages/Component

The Angular 7 routes already added when we create new Angular 7 application in the previous step. Before configuring the routes, type this command to create a new Angular 7 components.

ng g component books
ng g component books/detail
ng g component books/add
ng g component books/edit

Open client/src/app/app.module.ts then you will see those components imported and declared in @NgModule declarations. Next, open and edit src/app/app-routing.module.ts then add these imports.

import { BooksComponent } from './books/books.component';
import { DetailComponent } from './books/detail/detail.component';
import { AddComponent } from './books/add/add.component';
import { EditComponent } from './books/edit/edit.component';

Add these arrays to the existing empty array of routes constant.

const routes: Routes = [
  {
    path: 'books',
    component: BooksComponent,
    data: { title: 'List of Books' }
  },
  {
    path: 'books/detail/:id',
    component: DetailComponent,
    data: { title: 'Book Details' }
  },
  {
    path: 'books/add',
    component: AddComponent,
    data: { title: 'Add Book' }
  },
  {
    path: 'books/edit/:id',
    component: EditComponent,
    data: { title: 'Edit Book' }
  },
  { path: '',
    redirectTo: '/books',
    pathMatch: 'full'
  }
];

Open and edit client/src/app/app.component.html and you will see the existing router outlet. Next, modify this HTML page to fit the CRUD page.

<!--The content below is only a placeholder and can be replaced.-->
<div style="text-align:center">
  <h1>
    Welcome to {{ title }}!
  </h1>
  <img width="300" alt="Angular Logo" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNTAgMjUwIj4KICAgIDxwYXRoIGZpbGw9IiNERDAwMzEiIGQ9Ik0xMjUgMzBMMzEuOSA2My4ybDE0LjIgMTIzLjFMMTI1IDIzMGw3OC45LTQzLjcgMTQuMi0xMjMuMXoiIC8+CiAgICA8cGF0aCBmaWxsPSIjQzMwMDJGIiBkPSJNMTI1IDMwdjIyLjItLjFWMjMwbDc4LjktNDMuNyAxNC4yLTEyMy4xTDEyNSAzMHoiIC8+CiAgICA8cGF0aCAgZmlsbD0iI0ZGRkZGRiIgZD0iTTEyNSA1Mi4xTDY2LjggMTgyLjZoMjEuN2wxMS43LTI5LjJoNDkuNGwxMS43IDI5LjJIMTgzTDEyNSA1Mi4xem0xNyA4My4zaC0zNGwxNy00MC45IDE3IDQwLjl6IiAvPgogIDwvc3ZnPg==">
</div>

<div class="container">
  <router-outlet></router-outlet>
</div>

Finally, open and edit src/app/app.component.scss then replace all SASS codes with this.

.container {
  padding: 20px;
}

11. Display List of Books using Angular 7 Material

We will be using Angular 7 Material as UI/UX component. First, we have to install these modules to the Angular 7 application. Type this Angular 7 Schema to install it.

ng add @angular/material

If there are questions like below, just use the default answer.

? Enter a prebuilt theme name, or "custom" for a custom theme: purple-green
? Set up HammerJS for gesture recognition? Yes
? Set up browser animations for Angular Material? Yes

We will register all required Angular Material components or modules to client/src/app/app.module.ts. Open and edit that file then add this imports.

import {
  MatInputModule,
  MatPaginatorModule,
  MatProgressSpinnerModule,
  MatSortModule,
  MatTableModule,
  MatIconModule,
  MatButtonModule,
  MatCardModule,
  MatFormFieldModule } from "@angular/material";

Of course we will use Angular 7 Reactive Form module, for that, modify FormsModule import to add ReactiveFormsModule.

import { FormsModule, ReactiveFormsModule } from '@angular/forms';

Register the above modules to @NgModule imports array.

imports: [
  ...
  ReactiveFormsModule,
  BrowserAnimationsModule,
  MatInputModule,
  MatTableModule,
  MatPaginatorModule,
  MatSortModule,
  MatProgressSpinnerModule,
  MatIconModule,
  MatButtonModule,
  MatCardModule,
  MatFormFieldModule
],

Next, to display a list of Books. Open and edit client/src/app/books/books.component.ts that previously generated then add these imports.

import { Apollo } from 'apollo-angular';
import gql from 'graphql-tag';
import { Book } from './book';

Declare all required variables for hold response, data, Angular Material table column and loading spinner control.

displayedColumns: string[] = ['title', 'author'];
data: Book[] = [];
resp: any = {};
isLoadingResults = true;

Inject the Apollo Angular module to the constructor.

constructor(private apollo: Apollo) {
}

Add a gql query inside ngOnInit() function.

ngOnInit() {
  this.apollo.query({
    query: gql `{ books { _id, title, author } }`
  }).subscribe(res => {
    this.resp = res;
    this.data = this.resp.data.books;
    console.log(this.data);
    this.isLoadingResults = false;
  });
}

Next, open and edit client/src/app/books/books.component.html then replace all HTML tags with this.

<div class="example-container mat-elevation-z8">
  <div class="example-loading-shade"
       *ngIf="isLoadingResults">
    <mat-spinner *ngIf="isLoadingResults"></mat-spinner>
  </div>
  <div class="button-row">
    <a mat-flat-button color="primary" [routerLink]="['/books/add']"><mat-icon>add</mat-icon></a>
  </div>
  <div class="mat-elevation-z8">
    <table mat-table [dataSource]="data" class="example-table"
           matSort matSortActive="title" matSortDisableClear matSortDirection="asc">

      <!-- Product Name Column -->
      <ng-container matColumnDef="title">
        <th mat-header-cell *matHeaderCellDef>Title</th>
        <td mat-cell *matCellDef="let row">{{row.title}}</td>
      </ng-container>

      <!-- Product Price Column -->
      <ng-container matColumnDef="author">
        <th mat-header-cell *matHeaderCellDef>Author</th>
        <td mat-cell *matCellDef="let row">{{row.author}}</td>
      </ng-container>

      <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
      <tr mat-row *matRowDef="let row; columns: displayedColumns;" [routerLink]="['/books/detail/', row._id]"></tr>
    </table>
  </div>
</div>

Finally, add some styles for this page by open and edit client/src/app/books/books.component.scss then add these lines of SCSS codes.

/* Structure */
.example-container {
  position: relative;
  padding: 5px;
}

.example-table-container {
  position: relative;
  max-height: 400px;
  overflow: auto;
}

table {
  width: 100%;
}

.example-loading-shade {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 56px;
  right: 0;
  background: rgba(0, 0, 0, 0.15);
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.example-rate-limit-reached {
  color: #980000;
  max-width: 360px;
  text-align: center;
}

/* Column Widths */
.mat-column-number,
.mat-column-state {
  max-width: 64px;
}

.mat-column-created {
  max-width: 124px;
}

.mat-flat-button {
  margin: 5px;
}

12. Show and Delete Books

On the list of Books page we have a clickable row that can redirect to the show details page. Next, open and edit client/src/app/books/detail/detail.component.ts then add these imports.

import { ActivatedRoute, Router } from '@angular/router';
import { Apollo, QueryRef } from 'apollo-angular';
import gql from 'graphql-tag';
import { Book } from '../book';

Declare a constant variable before the class name for query and delete a book by ID.

const bookQuery = gql`
  query book($bookId: String) {
    book(id: $bookId) {
      _id
      isbn
      title
      author
      description
      published_year
      publisher
      updated_date
    }
  }
`;

const deleteBook = gql`
  mutation removeBook($id: String!) {
    removeBook(id:$id) {
      _id
    }
  }
`;

Next, declare all required variables before the constructor.

book: Book = { id: '', isbn: '', title: '', author: '', description: '', publisher: '', publishedYear: null, updatedDate: null };
isLoadingResults = true;
resp: any = {};
private query: QueryRef<any>;

Inject above imported modules to the constructor.

constructor(private apollo: Apollo, private router: Router, private route: ActivatedRoute) { }

Add a function for get a single Book data by ID.

getBookDetails() {
  const id = this.route.snapshot.params.id;
  this.query = this.apollo.watchQuery({
    query: bookQuery,
    variables: { bookId: id }
  });

  this.query.valueChanges.subscribe(res => {
    this.book = res.data.book;
    console.log(this.book);
    this.isLoadingResults = false;
  });
}

Call that function from ngOnInit function.

ngOnInit() {
  this.getBookDetails();
}

Add a function for delete a book by ID.

deleteBook() {
  this.isLoadingResults = true;
  const bookId = this.route.snapshot.params.id;
  this.apollo.mutate({
    mutation: deleteBook,
    variables: {
      id: bookId
    }
  }).subscribe(({ data }) => {
    console.log('got data', data);
    this.isLoadingResults = false;
    this.router.navigate(['/books']);
  }, (error) => {
    console.log('there was an error sending the query', error);
    this.isLoadingResults = false;
  });
}

For the view, open and edit client/src/app/books/detail/detail.component.html then replace all HTML tags with these lines of HTML tags.

<div class="example-container mat-elevation-z8">
  <div class="example-loading-shade"
       *ngIf="isLoadingResults">
    <mat-spinner *ngIf="isLoadingResults"></mat-spinner>
  </div>
  <div class="button-row">
    <a mat-flat-button color="primary" [routerLink]="['/books']"><mat-icon>list</mat-icon></a>
  </div>
  <mat-card class="example-card">
    <mat-card-header>
      <mat-card-title><h2>{{book.title}}</h2></mat-card-title>
      <mat-card-subtitle>{{book.author}}</mat-card-subtitle>
    </mat-card-header>
    <mat-card-content>
      <dl>
        <dt>ISBN:</dt>
        <dd>{{book.isbn}}</dd>
        <dt>Description:</dt>
        <dd>{{book.description}}</dd>
        <dt>Publisher:</dt>
        <dd>{{book.publisher}}</dd>
        <dt>Published Year:</dt>
        <dd>{{book.published_year}}</dd>
        <dt>Update Date:</dt>
        <dd>{{book.updated_date}}</dd>
      </dl>
    </mat-card-content>
    <mat-card-actions>
      <a mat-flat-button color="primary" [routerLink]="['/books/edit', book._id]"><mat-icon>edit</mat-icon></a>
      <a mat-flat-button color="warn" (click)="deleteBook(book._id)"><mat-icon>delete</mat-icon></a>
    </mat-card-actions>
  </mat-card>
</div>

To adjust the style, open and edit client/src/app/books/detail/detail.component.scss then add these lines of SCSS codes.

/* Structure */
.example-container {
  position: relative;
  padding: 5px;
}

.example-loading-shade {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 56px;
  right: 0;
  background: rgba(0, 0, 0, 0.15);
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mat-flat-button {
  margin: 5px;
}

13. Add a New Book using Angular 7 Material

In the list of Book we have an Add button that will redirect to the Add Page. Next, open and edit client/src/app/books/add/add.component.ts then add these imports.

import { Router } from '@angular/router';
import { FormBuilder, FormGroup, NgForm, Validators } from '@angular/forms';
import { Apollo } from 'apollo-angular';
import gql from 'graphql-tag';

Add a constant of gql query after the imports for submitting or post a new Book data.

const submitBook = gql`
  mutation addBook(
    $isbn: String!,
    $title: String!,
    $author: String!,
    $description: String!,
    $publisher: String!,
    $published_year: Int!) {
    addBook(
      isbn: $isbn,
      title: $title,
      author: $author,
      description: $description,
      publisher: $publisher,
      published_year: $published_year) {
      _id
    }
  }
`;

Declare all required variables before the constructor.

book: any = { isbn: '', title: '', author: '', description: '', publisher: '', publishedYear: null, updatedDate: null };
isLoadingResults = false;
resp: any = {};
bookForm: FormGroup;
isbn = '';
title = '';
author = '';
description = '';
publisher = '';
publishedYear: number = null;

Inject above imported modules to the constructor.

constructor(
  private apollo: Apollo,
  private router: Router,
  private formBuilder: FormBuilder
) { }

Initialize Angular 7 form group inside ngOnInit function.

ngOnInit() {
  this.bookForm = this.formBuilder.group({
    isbn : [null, Validators.required],
    title : [null, Validators.required],
    author : [null, Validators.required],
    description : [null, Validators.required],
    publisher : [null, Validators.required],
    publishedYear : [null, Validators.required]
  });
}

Add a function to get the form controls from the form group.

get f() {
  return this.bookForm.controls;
}

Add a function to submit or post a new book data.

onSubmit(form: NgForm) {
  this.isLoadingResults = true;
  const bookData = form.value;
  this.apollo.mutate({
    mutation: submitBook,
    variables: {
      isbn: bookData.isbn,
      title: bookData.title,
      author: bookData.author,
      description: bookData.description,
      publisher: bookData.publisher,
      published_year: bookData.publishedYear
    }
  }).subscribe(({ data }) => {
    console.log('got data', data);
    this.isLoadingResults = false;
    this.router.navigate(['/books/detail/', data.addBook._id]);
  }, (error) => {
    console.log('there was an error sending the query', error);
    this.isLoadingResults = false;
  });
}

Next, open and edit client/src/app/books/add/add.component.html then replace all HTML tags with this.

<div class="example-container mat-elevation-z8">
  <div class="example-loading-shade"
       *ngIf="isLoadingResults">
    <mat-spinner *ngIf="isLoadingResults"></mat-spinner>
  </div>
  <div class="button-row">
    <a mat-flat-button color="primary" [routerLink]="['/books']"><mat-icon>list</mat-icon></a>
  </div>
  <mat-card class="example-card">
    <form [formGroup]="bookForm" #f="ngForm" (ngSubmit)="onSubmit(f)" novalidate>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="ISBN" formControlName="isbn"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('isbn').valid && bookForm.get('isbn').touched">Please enter ISBN</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Title" formControlName="title"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('title').valid && bookForm.get('title').touched">Please enter Title</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Author" formControlName="author"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('author').valid && bookForm.get('author').touched">Please enter Author</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <textarea matInput placeholder="Description" formControlName="description"
               [errorStateMatcher]="matcher"></textarea>
        <mat-error>
          <span *ngIf="!bookForm.get('description').valid && bookForm.get('description').touched">Please enter Description</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Publisher" formControlName="publisher"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('publisher').valid && bookForm.get('publisher').touched">Please enter Publisher</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Published Year" type="number" formControlName="publishedYear"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('publishedYear').valid && bookForm.get('publishedYear').touched">Please enter Published Year</span>
        </mat-error>
      </mat-form-field>
      <div class="button-row">
        <button type="submit" [disabled]="!bookForm.valid" mat-flat-button color="primary"><mat-icon>save</mat-icon></button>
      </div>
    </form>
  </mat-card>
</div>

Give a litle style by open and edit client/src/app/books/add/add.component.scss then add this lines of SCSS codes.

/* Structure */
.example-container {
  position: relative;
  padding: 5px;
}

.example-form {
  min-width: 150px;
  max-width: 500px;
  width: 100%;
}

.example-full-width {
  width: 100%;
}

.example-full-width:nth-last-child() {
  margin-bottom: 10px;
}

.button-row {
  margin: 10px 0;
}

.mat-flat-button {
  margin: 5px;
}

14. Edit a Book using Angular 7 Material

We have put an edit button inside the Book Detail component for a redirect to Edit page. Now, open and edit client/src/app/books/edit/edit.component.ts then add these imports.

import { ActivatedRoute, Router } from '@angular/router';
import { FormBuilder, FormGroup, NgForm, Validators } from '@angular/forms';
import { Apollo, QueryRef } from 'apollo-angular';
import gql from 'graphql-tag';

Add gql query before the class name for getting single Book by ID and submit book data.

const bookQuery = gql`
  query book($bookId: String) {
    book(id: $bookId) {
      _id
      isbn
      title
      author
      description
      published_year
      publisher
      updated_date
    }
  }
`;

const submitBook = gql`
  mutation updateBook(
    $id: String!,
    $isbn: String!,
    $title: String!,
    $author: String!,
    $description: String!,
    $publisher: String!,
    $published_year: Int!) {
    updateBook(
      id: $id,
      isbn: $isbn,
      title: $title,
      author: $author,
      description: $description,
      publisher: $publisher,
      published_year: $published_year) {
      updated_date
    }
  }
`;

Add all required variables before the constructor.

book: any = { _id: '', isbn: '', title: '', author: '', description: '', publisher: '', publishedYear: null, updatedDate: null };
isLoadingResults = true;
resp: any = {};
private query: QueryRef<any>;
bookForm: FormGroup;
id = '';
isbn = '';
title = '';
author = '';
description = '';
publisher = '';
publishedYear: number = null;

Inject above imported modules to the constructor.

constructor(
  private apollo: Apollo,
  private route: ActivatedRoute,
  private router: Router,
  private formBuilder: FormBuilder) { }

Initialize the Angular 7 form group to the ngOnInit function.

ngOnInit() {
  this.bookForm = this.formBuilder.group({
    isbn : [null, Validators.required],
    title : [null, Validators.required],
    author : [null, Validators.required],
    description : [null, Validators.required],
    publisher : [null, Validators.required],
    publishedYear : [null, Validators.required]
  });
}

Add a function to get the form controls from the form group.

get f() {
  return this.bookForm.controls;
}

Add a function to get a single book data by ID.

getBookDetails() {
  const id = this.route.snapshot.params.id;
  this.query = this.apollo.watchQuery({
    query: bookQuery,
    variables: { bookId: id }
  });

  this.query.valueChanges.subscribe(res => {
    this.book = res.data.book;
    console.log(this.book);
    this.id = this.book._id;
    this.isLoadingResults = false;
    this.bookForm.setValue({
      isbn: this.book.isbn,
      title: this.book.title,
      author: this.book.author,
      description: this.book.description,
      publisher: this.book.publisher,
      publishedYear: this.book.published_year
    });
  });
}

Call that function from the ngOnInit function.

ngOnInit() {
  ...
  this.getBookDetails();
}

Add a function for submitting the Book data to the GraphQL.

onSubmit(form: NgForm) {
  this.isLoadingResults = true;
  console.log(this.id);
  const bookData = form.value;
  this.apollo.mutate({
    mutation: submitBook,
    variables: {
      id: this.id,
      isbn: bookData.isbn,
      title: bookData.title,
      author: bookData.author,
      description: bookData.description,
      publisher: bookData.publisher,
      published_year: bookData.publishedYear
    }
  }).subscribe(({ data }) => {
    console.log('got data', data);
    this.isLoadingResults = false;
  }, (error) => {
    console.log('there was an error sending the query', error);
    this.isLoadingResults = false;
  });
}

Add a function to enter the Book details after click a Details button.

bookDetails() {
  this.router.navigate(['/books/detail/', this.id]);
}

Next, open and edit client/src/app/books/edit/edit.component.html then replace all HTML tags with this.

<div class="example-container mat-elevation-z8">
  <div class="example-loading-shade"
       *ngIf="isLoadingResults">
    <mat-spinner *ngIf="isLoadingResults"></mat-spinner>
  </div>
  <div class="button-row">
    <a mat-flat-button color="primary" (click)="bookDetails()"><mat-icon>info</mat-icon></a>
  </div>
  <mat-card class="example-card">
    <form [formGroup]="bookForm" #f="ngForm" (ngSubmit)="onSubmit(f)" novalidate>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="ISBN" formControlName="isbn"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('isbn').valid && bookForm.get('isbn').touched">Please enter ISBN</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Title" formControlName="title"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('title').valid && bookForm.get('title').touched">Please enter Title</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Author" formControlName="author"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('author').valid && bookForm.get('author').touched">Please enter Author</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <textarea matInput placeholder="Description" formControlName="description"
               [errorStateMatcher]="matcher"></textarea>
        <mat-error>
          <span *ngIf="!bookForm.get('description').valid && bookForm.get('description').touched">Please enter Description</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Publisher" formControlName="publisher"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('publisher').valid && bookForm.get('publisher').touched">Please enter Publisher</span>
        </mat-error>
      </mat-form-field>
      <mat-form-field class="example-full-width">
        <input matInput placeholder="Published Year" type="number" formControlName="publishedYear"
               [errorStateMatcher]="matcher">
        <mat-error>
          <span *ngIf="!bookForm.get('publishedYear').valid && bookForm.get('publishedYear').touched">Please enter Published Year</span>
        </mat-error>
      </mat-form-field>
      <div class="button-row">
        <button type="submit" [disabled]="!bookForm.valid" mat-flat-button color="primary"><mat-icon>save</mat-icon></button>
      </div>
    </form>
  </mat-card>
</div>

For styling, open and edit client/src/app/books/edit/edit.component.scss then add these lines of SCSS codes.

/* Structure */
.example-container {
  position: relative;
  padding: 5px;
}

.example-form {
  min-width: 150px;
  max-width: 500px;
  width: 100%;
}

.example-full-width {
  width: 100%;
}

.example-full-width:nth-last-child() {
  margin-bottom: 10px;
}

.button-row {
  margin: 10px 0;
}

.mat-flat-button {
  margin: 5px;
}

15. Run and Test GraphQL CRUD from the Angular 7 Application

Before the test, the GraphQL CRUD from the Angular 7 Application, just makes sure that you have run MongoDB server and Express.js server. If not yet, run those servers in different Terminal tabs. Next, run the Angular 7 application from the different terminal tabs.

ng serve

In the browser go to this URL localhost:4200 and here the whole application looks like.

That it’s, we have finished the Node, Express, Angular 7, GraphQL and MongoDB CRUD Web App. If you can’t follow the steps of the tutorial, you can compare it with the working source code from our GitHub.

Thanks for reading ❤

#node-js #express #angular #graphql #mongodb #web-development