Create the Backend | Angular Todos
Table of Contents
- Step 1 - Create a New App
- Step 2 - Create an Entity
- Step 3 - Create a Role
- Step 4 - Assign Permissions
- Step 5 - Connect to GitHub
- Step 6 - Build the Backend
- Step 7 - Run the Backend
- Step 8 - Wrap Up
Step 1 - Create a New App
Hopefully, you've had the chance to create an Amplication account, but if not, don't fret! Visit https://app.amplication.com/ and you'll be directed to the login screen. Here you can log in to an existing Amplication account, or create one, by signing in with a GitHub account.
You should end up at the
New Apppage, but if not you can get to it here.
New Appbutton in the top right corner.
Name your application whatever you'd like, and then click "Create Project."
Click "New service +," in the top right corner, and then "Create Service" in the bottom right of the new page.
Step 2 - Create an Entity
An entity is equivalent to a collection in a NoSQL database or a table in a relational database. By default, a User entity is created for you. This entity will eventually help us handle authentication. But first, let's deal with the backend. The main entity will be used to store tasks created by users.
Click the "Entities" button in the left hand bar to go to the entities page.
New Entitymodal appears, input
Taskinto the input field and click
With the entity created we'll want to define a few fields for task elements.
On the left-hand panel, you'll see the
Fieldsthis entity has, and at the very bottom, there will be an option to add a field.
The first field will be
Text. Type that into the
Add fieldinput and hit
The new field will be created and a few options will appear.
Notice a dropdown for the
Data Typeof this field is set to
Single Line Text. That's perfect as it'll be a string input of a task. There are many different data types Amplication can enforce for fields.
The only change that needs to be made here is this will be a required field. Toggle the
Changes will be automatically saved.
Like before, create a new field called
Completed. This field should also be a required field, but we will change the data type. Click the
Data Typedropdown and change this field to be a
The final field we will need to create should be called
UID. This field will be used to relate a task to a user. Mark this as a required field. In the
Data Typedropdown select
Relation to Entity.
Related Entitydropdown should appear, select
User. A modal asking to create a relation between a Task and a User will appear. Click
Createto create the relation. To learn more about entity relations, there's an article on the docs website here.
Step 3 - Create a Role
Amplication allows for granular permission to create, read, update, and delete entries in the different entities of the backend.
User's who will be creating tasks in the Todo app will need to be granted certain permissions to create, read, and update their tasks and prevent them from doing other things.
Rolesicon on the left-hand panel.
Then, much like the properties, we added to the
Taskentity, create a role called
Step 4 - Assign Permissions
With a role for users of the Todo app created, we'll want to assign certain permissions to the
Todo User role.
Return to the entities page by clicking the
Entitiesicon on the left-hand panel, again.
By default, every role has CRUD (create, read, update, and delete) access to every entity. It is important to limit the scope of our Todo users.
Userentity from the list of entities, and on the left-hand, panel select
Every type of command is granted to
All Roles. Users with the
Todo Userrole have full access to the
Userentity. This can be dangerous.
The default admin account created by the backend has the role
User, so we don't want to mess with that. What we will eventually do is have it so all new users are assigned the
Todo Userrole, and we will limit their access to certain commands.
Toggle the permissions for each of the entity's commands to
Granularand toggle on the
Userrole. Now the only user who can access
Useraccounts will have the
Userrole, which will belong only to the admin account.
Return to the
Entitiespage and now select the
Permissions. Toggle the
Granularand enable access to the
Users (the admin) and
Todo Users (regular users of the app) will be able to create, read, and update tasks; but only
Users will be able to delete tasks.
Step 5 - Connect to GitHub
Amplication provides code sync with GitHub. We'll want to set this up with the repository we created in the previous step.
Connect to Githubicon on the left-hand panel. Then click
Go to project settings.
Connect to Github.This will allow you to connect with either your GitHub account, or with a GitHub organization.
Select repository.From here select the GitHub repository we created previously.
Step 6 - Build the Backend
With the new Task entity created, and a relation with User's created, and connecting our project with GitHub. We're now ready to commit our changes and build the application.
On the right-side panel is the
Pending changes where the changes to
User, as well as other changes, will appear.
Commit changes & buildto finalize the changes and to create a Pull Request on GitHub with the backend we created.
Amplication by default creates a secure environment where all requests need to be authenticated. For this use case, we will want to ease some of those protections. Thanks to Amplication's extensibility, we can build on top of everything that was generated for us.
Visit GitHub and navigate to the repository that's linked to this project. You'll see that a new pull request has been opened!
Review the pull request and the code that was generated for yourself, then merge the pull request.
Finally, return to your code editor and pull down the changes made on GitHub.
Step 7 - Run the Backend
serverfolders generated by Amplication are two new node projects that need to be set up. One thing both will need is their dependencies. In the
"postinstall": "npm i --prefix web && npm i --prefix admin-ui && npm i --prefix server"
Open a new terminal and run this command
npm run postinstall
This command will install the dependencies of all the subfolders. Another useful aspect of this command is that if you were to push this project to GitHub and cloned the repo when you run
npm installthis script will occur after the install to install the dependencies of the subfolders automatically.
Install npm-run-all as a dev dependency as follows:
npm install -D npm-run-all
package.jsonand add the following script as well:
"start": "npm-run-all -p start:frontend start:backend",
"start:frontend": "npm --prefix web start",
"start:admin": "npm --prefix admin-ui start",
"start:backend": "npm --prefix server start",
We've also set the start to script to run our frontend and backend code at the same time.
Before starting the server there are a few additional steps required. Read
server/README.mdfor directions to:
- Create a Prisma client
- Start a database in Docker
- Initiate the database
When those steps have been completed run the following command:
npm run start
Step 8 - Wrap Up
The frontend of the Todo app will be running at http://localhost:4200/, and the backend will be running at http://localhost:3000/.
Visiting http://localhost:3000/ will greet you with a
404 error. Instead, visit http://localhost:3000/api/ to see all the endpoints of the backend and to see what our REST endpoints will look like.
With our backend created and running locally, we're almost ready to link it to the frontend. First, we'll need to make some additions to the code.
To view the changes for this step, visit here.