Introduction to Strapi : Headless CMS for Building Web Applications

For us, developers, starting a new web project can be a tedious job. It raises questions like:

What technology should I use for the front-end?
What technology should I use for the back-end?
What database is the best?

Because nowadays all Javascript technologies like React, Angular and Vue are very popular for building Web applications, so we can get an answer for the first question very fast.

But what about the back-end? Should I use NodeJS or .NET Core? Is it better to use a relational or non-relational database? Well, Strapi has the answer to all these questions.

What is Strapi?

Strapi is an open-source Headless CMS that gives developers the freedom to choose their favorite tools and frameworks. With all the plugins and features Strapi gives the developers the ability for customization and extensibility. Strapi is also very Developer-Friendly by providing an API that can be easily accessed either via REST or GraphQL endpoint.

In this article, we are going to build a simple web application using Strapi and Angular.

First, we are going to set up and build our API.

Install Strapi

Requirements: Node.js 12.x and npm 6.x

Create a new project

npx create-strapi-app blog_api --quickstart

If we want to customize our application to use the specific database we need to run the command without

--quickstart

argument. By default, Strapi is using

sqlite

Once the setup from the command above is finished Strapi will automatically run (NOTE: when manually start the project run the command

strapi develop

) and we can navigate to our admin panel on the following link: http://localhost:1337/admin. When you navigate you will able to see the registration form.

When we finish with registering our first user, we can start building our API.

First, what we need to do for our Blog Application is to define the models that we will have. We will define three models: Page, Post, and Content.

To create a new Model navigate to Content Type Builder.

Our model

Content

will have:

Title - type
```
Text
```
Value - type
```
RichText
```
IsPublished - type
```
boolean
```
CoverImage - type
```
Media
```
Relation to
```
Post
```
(Content belong to many
```
Posts
```
)
Relation to
```
Page
```
(Content belong to many
```
Pages
```
)

Page

model will have:

Name - type
```
Text
```
Relation to
```
Content
```
(
```
Page
```
has many
```
Contents
```
)
Relation to
```
Post
```
(
```
Page
```
has many and belongs to many
```
Posts
```
)

and

Post

model will have:

IsDeleted - type
```
boolean
```
Relation to
```
Page
```
(
```
Post
```
has many and belongs to many
```
Pages
```
)
Relation to
```
Contents
```
(
```
Post
```
has many
```
Contents
```
)

As soon as we define our models we are ready to create some pages, contents, and posts. We can simply do that by navigating to each model and click

Add new [name-of-the-model]

Now, when we have models and data into our database we need to give access to our visitors of blog application. To do that we need to navigate to

Roles and Permissions

tab in the menu. We can see there are by default two types of roles:

Public

and

Authorized

. We navigate to

Public

role and select:

And that's it. Our API is ready. Now we only need to make our web application.

Angular Application

For creating our Angular application we will use Angular CLI.

Install the Angular CLI with the following command:

npm install -g @angular/cli

Run the following commands to create and run a new angular app:

ng new blog-web 
cd blog-web 
ng serve

If you navigate to http://localhost:4200/ you will able to see the new app.

Now, we can start with styling our application and access data from our API. First, we will create services and API calls to get our data from Strapi. Navigate to

src

folder and run the following commands:

mkdir services
cd services
ng generate service page
ng generate service post
ng generate service content

Angular CLI will create these services so we are ready for coding. In

environment.ts

we will put our API URL.

Navigate to page service and insert the following code:

page-service.ts

We created two methods: one for getting all pages and one for getting page by id. We will make the same for

post

and

content

services.

NOTE: Before using

HttpClient

we need to register into

app-module.ts

Go to app-module.ts
Import the
```
HttpClientModule
```
from
```
@angular/common/http
```
,

import { HttpClientModule } from '@angular/common/http'

Add it to the

@NgModule.imports

array.

imports:[HttpClientModule,  ...]

post-service.ts

content-service.ts

Next, we will create

post-component

that will contain style and functionality for posts and we will use

app-component

for displaying our landing page. Navigate to

app

folder and create a new folder called components. Here, we will store all components that we use in our blog application. With the following command we can generate a new component:

ng generate component post

Insert the following code into the post component.

post.component.html

post.component.scss

post.component.ts

Because we are using bootstrap classes we need to include bootstrap into our project as well. We can do that by adding the following into

index.html

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/cosmo/bootstrap.min.css">

And we are almost done. The only thing that left is to modify

app-component

and our blog is ready for use.

app.component.html

app.component.scss

app.component.ts

Congratulations, we successfully built a Blog application.

Conclusion

Feel free to continue working on your blog. You can try various scenarios navigation, styling e.t.c. Play with models into Strapi and API calls from your Angular application.

The source code of this tutorial is available on Github. I hope you enjoyed through this adventure.

Also published on https://blog.codechem.com/the-power-of-strapi-building-web-application-has-never-been-easier