How to Create Nested Grid using Angular 8

Introduction

In this article, we will learn how we create a nested grid in Angular 8.

How it works?

We are using the grid list to separate the page into small sections. In each section, we want to place a different component, where one of these components is another smaller grid.

Prerequisite

Basic knowledge of Angular
Visual Studio Code must be installed
Angular CLI must be installed
Node JS must be installed

FRONTEND

Step 1. Let's create an Angular project using the following npm command.

ng new nestedGrid

Step 2. Open the newly created project in Visual Studio code and install Bootstrap in this project.

npm install bootstrap --save

Now open the styles.css file and add the Bootstrap file reference. To add a reference in the styles.css file, add this line.

@import '~bootstrap/dist/css/bootstrap.min.css';

Step 3. Now, let's create a new component by using the following command.

ng g c product

Step 4. Now create a new service using the following command.

ng generate service product

Step 5. Now, open the 'product.component.html' and paste the following code to see the HTML template.

<p class="card">
  <p class="card-body pb-0">
    <h4 style="text-align: center;">Example of Angular Nested Grid</h4>
    <p class="row">
      <p class="col-12 col-md-12">
        <p class="card">
          <p class="card-body position-relative">
            <p class="table-responsive cnstr-record product-tbl">
              <table class="table table-bordered heading-hvr">
                <thead>
                  <tr>
                    <th> </th>
                    <th width="50">Art.No</th>
                    <th>Brand</th>
                    <th>Price/Unit</th>
                    <th>Provider</th>
                    <th>P. Art. N</th>
                    <th>S. A/C</th>
                    <th>Buy A/C</th>
                  </tr>
                </thead>
                <tbody *ngFor="let product of products; let i = index">
                  <tr>
                    <td align="center">
                      <a class="expand-row" *ngIf="!hideme[i]" (click)="showProductCountryInfo(i,product.ProductId)">
                        <img src="../../assets/Images/plus.png"/>
                      </a>
                      <a class="expand-row" *ngIf="hideme[i]" (click)="hideme[i] = !hideme[i]">
                        <img src="../../assets/Images/minus.png"/>
                      </a>
                    </td>
                    <td align="center">{{product.ArtNo}}</td>
                    <td>{{product.Brand}}</td>
                    <td>{{product.Price }}</td>
                    <td>{{product.Provider}}</td>
                    <td>{{product.ProviderArtNo}}</td>
                    <td>{{product.SalesAccount}}</td>
                    <td>{{product.BuyAccount}}</td>
                  </tr>
                  <tr [hidden]="!hideme[i]" class="sub-table no-bg">
                    <td align="center"> </td>
                    <td colspan="15" class="p-0">
                      <table class="table mb-0 table-striped">
                        <thead class="bg-dark text-white">
                          <tr>
                            <th>CountryName</th>
                            <th>Price/Unit</th>
                            <th>Sales Account</th>
                            <th>Buy Account</th>
                          </tr>
                        </thead>
                        <tbody>
                          <tr *ngFor="let productCountryInfo of productCountryInformation[i]">
                            <td>{{productCountryInfo.CountryName}}</td>
                            <td>{{productCountryInfo.Price}}</td>
                            <td>{{productCountryInfo.SalesAccount}}</td>
                            <td>{{productCountryInfo.BuyAccount}}</td>
                          </tr>
                        </tbody>
                      </table>
                    </td>
                  </tr>
                </tbody>
              </table>
            </p>
          </p>
        </p>
      </p>
    </p>
  </p>
</p>

Step 6. After that open the 'product.component.ts' file and add the following code in this file where our logic has been written.

import { Component, OnInit } from '@angular/core';
import { ProductsService } from './products.service';

@Component({
  selector: 'app-products',
  templateUrl: './products.component.html',
  styleUrls: ['./products.component.css']
})
export class ProductsComponent implements OnInit {

  products = [];
  countryCode: any;
  currencySymbol: any;
  productCountryInformation: any = [];
  hideme = [];
  Index: any;
  countryId: any;
  country: any;
  priceToDisplay = [];

  constructor(private _productService: ProductsService) {
  }

  ngOnInit() {
    this.countryId = 0;
    this.getProducts(this.countryId);
  }

  public getProducts(countryId) {
    let data = [];
    this._productService.getAllProducts(countryId).subscribe((data: any) => {
      this.products = data;
    })
  }

  public showProductCountryInfo(index, productId) {
    this._productService.countryInfo(productId).subscribe((res: any) => {
      this.productCountryInformation[index] = res;
    })
    this.hideme[index] = !this.hideme[in

Step 7. Next, open the 'product.component.css' file and paste the code for styling.

@charset "utf-8";
/* CSS Document */
@media all {
    * {padding:0px;margin:0px;}
    p {vertical-align:top;}
    img {max-width:100%;}
    html {-webkit-font-smoothing:antialiased; -moz-osx-font-smoothing:grayscale;}
    body {overflow:auto!important; width:100%!important;}
    html, body {background-color:#e4e5e6;}

    .card {border-radius:4px;}
    .card-header:first-child {border-radius:4px 4px 0px 0px;}

    /*Typekit*/
    html, body {font-family:'Roboto', sans-serif; font-weight:400; font-size:13px;}
    body {padding-top:52px;}

    p {font-family:'Roboto', sans-serif; color:#303030; font-weight:400; margin-bottom:1rem;}
    input, textarea, select {font-family:'Roboto', sans-serif;}

    h1,h2,h3,h4,h5,h6 {font-family:'Roboto', sans-serif; font-weight:700;}
    h1 {font-size:20px; color:#000000; margin-bottom:10px;}
    h2 {font-size:30px;}
    h3 {font-size:24px;}
    h4 {font-size:18px;}
    h5 {font-size:14px;}
    h6 {font-size:12px;}

    .row {margin-right:-8px; margin-left:-8px;}
    .col, .col-1, .col-10, .col-11, .col-12, .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-auto, .col-lg, .col-lg-1, .col-lg-10, .col-lg-11, .col-lg-12, .col-lg-2, .col-lg-3, .col-lg-4, .col-lg-5, .col-lg-6, .col-lg-7, .col-lg-8, .col-lg-9, .col-lg-auto, .col-md, .col-md-1, .col-md-10, .col-md-11, .col-md-12, .col-md-2, .col-md-3, .col-md-4, .col-md-5, .col-md-6, .col-md-7, .col-md-8, .col-md-9, .col-md-auto, .col-sm, .col-sm-1, .col-sm-10, .col-sm-11, .col-sm-12, .col-sm-2, .col-sm-3, .col-sm-4, .col-sm-5, .col-sm-6, .col-sm-7, .col-sm-8, .col-sm-9, .col-sm-auto, .col-xl, .col-xl-1, .col-xl-10, .col-xl-11, .col-xl-12, .col-xl-2, .col-xl-3, .col-xl-4, .col-xl-5, .col-xl-6, .col-xl-7, .col-xl-8, .col-xl-9, .col-xl-auto {padding-right:8px; padding-left:8px;}

    .card-header {background-color:#f0f3f5; border-bottom:1px solid #c8ced3; font-size:13px; font-weight:600; color:#464646; text-transform:uppercase; padding:.75rem 8px;}

    .cnstr-record th {white-space:nowrap; padding:.45rem .2rem; font-size:13px; border-bottom-width:0px!important;}
    .cnstr-record thead {background:#f0f3f5;}

    .cnstr-record .form-control {font-size:13px; padding:0px 0rem 0px 0.2rem; height:calc(2rem + 2px);}
    .cnstr-record select.form-control {padding-left:.05rem;}
    .cnstr-record .table td, .cnstr-record .table th {vertical-align:middle;}
    .cnstr-record .table td {padding:.3rem;}
    .cnstr-record .table td h4 {margin:0px;}

    .wp-50 {width:50px;}
    .wp-60 {width:60px;}
    .wp-70 {width:70px;}
    .wp-80 {width:80px;}
    .wp-90 {width:90px;}
    .wp-100 {width:100px;}
    .mw-auto {min-width:inherit;}
    .expand-row {width:100%; border:solid 1px #596269; display:inline-block; border-radius:3px; width:16px; height:16px; vertical-align:top; background:#596269; color:#ffffff!important;}
    .expand-row img {vertical-align:top; position:relative; top:2px;}
    .sub-table th {font-weight:400; font-size:12px;}
    .sub-table td {background:#efefef;}
    .no-bg td {background:inherit;}
    .mw-100 {max-width:100%;}
}

Step 8. At last, open the 'product.service.ts' file and add services to call our API.

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Injectable()

export class ProductsService {

    private url = "";

    constructor(public http: HttpClient) {
    }

    getAllProducts(countryCode) {
        this.url = 'http://localhost:49661/api/Company/getAllProducts?countryCode=' + countryCode;
        return this.http.get<any[]>(this.url);
    }

    countryInfo(productId) {
        this.url = 'http://localhost:49661/api/Company/getProductCountryInformation?productId=' + productId;
        return this.http.get<any[]>(this.url);
    }
}

Step 9. It's time to see the output in your terminal type 'ng serve -o' to compile and open it in the browser.

After loading our page you can see the output like in the below images.

Grid

Subgrid

Here, I am taking a product, for example, grid data is related to a product and its corresponding nested grid has information related to its parent grid.

You can check a nested grid by clicking the plus icon of the parent grid so that you can see the resultant nested grid based on the index, (i.e if you click on every 1st plus icon then you can only see its first product-related information. If you click on the second plus icon, then their product-related information would show.)

Now, the front-end part is done and it's time to add server-side code and backend code.

WEB API Create an ASP.NET Core application

Follow these steps to create an ASP.NET Core application.

Step 1. In Visual Studio 2019, click on File -> New -> Project.

Project

Step 2. Choose the Create option and select Asp.net web application.

Asp.net web

Step 3. Select Web API and click OK.

Web API

Step 4. Now right-click on the controller and then add a new item.

New item

Step 5. Choose Ado.net Entity Data Model and then click on Add.

Ado.net Entity

Step 6. The next step is EF Designer, just click on next.

EF Designer

Step 7. A new pop-up will show. Click on next. If yours isn't established, then click on a new connection.

New connection

Step 8. Copy your database connection server name and paste it into the server name textbox. You will see all the databases, select your database, and click on ok.

Database connection

Step 9. The next popup will show, paste your database server name, choose the database test for the connection then click on next. Here, in the new screen, select your tables and store the procedure. Then click on finish.

Server name

Our next step is to right-click on the controllers folder and add a new controller. Name it as "Product Controller" and add the following namespace in the student controller.

Here is the complete code for getting all the product data and their nested product information data.

Complete Product controller code

using System.Linq;
using System.Web.Http;
using CompanyDetails.Models;

namespace CompanyDetails.Controllers
{
    [RoutePrefix("api/Company")]
    public class CompanyController : ApiController
    {
        CompanyEntities2 DB = new CompanyEntities2();

        [HttpGet]
        [Route("getAllCountry")]
        public object getAllCountry()
        {
            return DB.Countries.ToList();
        }

        [HttpGet]
        [Route("getAllProducts")]
        public object getAllProducts(string countrycode)
        {
            var productDetails = DB.USP_GetAllProducts().ToList();
            return productDetails;
        }

        [HttpGet]
        [Route("getProductCountryInformation")]
        public object getProductCountryInformation(int ProductId)
        {
            var prod = DB.USP_getCountryInfo(ProductId).ToList();
            return prod;
        }
    }
}

Now, it's time to enable CORS. Go to Tools, open NuGet Package Manager, search for CORS and install the "Microsoft.Asp.Net.WebApi.Cors" package.

If you are running your frontend application in a different port and your server is running in another port, then to avoid a Cross-Origin-Resource-Sharing issue you have to add a small code in webapiconfig.cs file.

Open Webapiconfig. cs and add the following lines.

EnableCorsAttribute cors = new EnableCorsAttribute("*", "*", "*");
config.EnableCors(cors);

BACKEND

Here Back end related code we will do using the SQL server

The very first step is to create a database.

Create database

Let’s create a database on your local SQL Server. I hope you have installed SQL Server 2017 on your machine (you can use SQL Server 2008, 2012, or 2016, as well).

Step 1. Create a database product.

create database product

Step 2. Create a product table using the following code.

USE [Product]
GO
/****** Object:  Table [dbo].[Product]    Script Date: 12/18/2019 10:23:19 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Product](
    [ProductId] [int] IDENTITY(1,1) NOT NULL,
    [ProductCountryInformationId] [int] NULL,
      NULL,
      NULL,
      NULL,
      NULL,
 CONSTRAINT [PK_Product] PRIMARY KEY CLUSTERED 
(
    [ProductId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[Product]  WITH CHECK ADD  CONSTRAINT [FK_Product_ProductCountryInformation] FOREIGN KEY([ProductCountryInformationId])
REFERENCES [dbo].[ProductCountryInformation] ([ProductCountryInformationId])
GO
ALTER TABLE [dbo].[Product] CHECK CONSTRAINT [FK_Product_ProductCountryInformation]
GO

Make product ID the primary key

Step 3. Create a product information table using the following code.

USE [Product]
GO

/****** Object:  Table [dbo].[ProductCountryInformation]    Script Date: 12/18/2019 10:24:02 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[ProductCountryInformation](
    [ProductCountryInformationId] [int] NOT NULL,
    [Price] [decimal](18, 2) NULL,
      NULL,
      NULL,
      NULL,
    [ProductId] [int] NULL,
 CONSTRAINT [PK_ProductCountryInformation] PRIMARY KEY CLUSTERED 
(
    [ProductCountryInformationId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[ProductCountryInformation]  WITH CHECK ADD  CONSTRAINT [FK_ProductCountryInformation_Product] FOREIGN KEY([ProductId]) 
REFERENCES [dbo].[Product] ([ProductId])
GO
ALTER TABLE [dbo].[ProductCountryInformation] CHECK CONSTRAINT [FK_ProductCountryInformation_Product]
GO
ALTER TABLE [dbo].[ProductCountryInformation]  WITH CHECK ADD  CONSTRAINT [FK_ProductCountryInformation_ProductCountryInformation] FOREIGN KEY([ProductCountryInformationId]) 
REFERENCES [dbo].[ProductCountryInformation] ([ProductCountryInformationId])
GO
ALTER TABLE [dbo].[ProductCountryInformation] CHECK CONSTRAINT [FK_ProductCountryInformation_ProductCountryInformation]
GO

Now it is time to add some store procedures.

Step 4. All you have to do is paste the following code in a new query.

USE [Product]
GO

/****** Object:  StoredProcedure [dbo].[USP_GetAllProducts]    Script Date: 12/18/2019 10:24:35 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER Proc [dbo].[USP_GetAllProducts]
As
Begin
    Select  p.*,pci.Price,pci.BuyAccount,pci.SalesAccount from [Product] p    
  left join [ProductCountryInformation] pci    
  on p.ProductCountryInformationId=pci.ProductCountryInformationId    
End

USE [Product]
GO
/****** Object:  StoredProcedure [dbo].[USP_getCountryInfo]    Script Date: 12/18/2019 10:24:57 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER Proc [dbo].[USP_getCountryInfo]
@ProductId int
As
Begin
    select pci.* from ProductCountryInformation pci
    left join Product p on pci.ProductId=p.ProductId
    where pci.ProductId=@ProductId
End

With this step, we have successfully completed our front-end, web API, and back-end coding.

Conclusion

In this article, I have discussed how to create a nested grid in an Angular 8 Application. In my next article, which is a continuation of this part, we are going to learn about the JavaScript function tolocalestring() by changing the price by country, which will give their appropriate currency format.

Please give your valuable feedback/comments/questions about this article. Please let me know if you liked and understood this article and how I could improve it.

7 Comments

Join the conversation! Your thoughts help the community grow.

Junaid Shah6y ago
Thanks but I am getting an error:- Cannot read property '0' of undefined, when rendering the nested table via :-
- Siddharth Gajbhiye6y ago
  I will send you my stackblitz link you can check it there and let me know
Junaid Shah6y ago
I followed the pattern however I am getting an error when the page loads:- Cannot read property '0' of undefined
Sourav Kumar Das6y ago
Nice and useful article. Thanks for sharing.
- Siddharth Gajbhiye6y ago
  Thank you so much Sourav
Ankur Mistry6y ago
Useful stuff, thanks for sharing
- Siddharth Gajbhiye6y ago
  Thanks a lot Ankur.