How to Build an Angular Frontend and Connect it to a Backend?

in this tutorial, you’ll build a to do list application using angular and connect it to a managed backend service powered by back4app this guide is designed for you if you want to master essential crud (create, read, update, delete) operations and create a dynamic, responsive interface with angular by the end of this tutorial, your application will communicate seamlessly with a backend that handles data storage, authentication, and more building a full stack application often involves complex backend configuration and database management to simplify your workflow, we use back4app— a robust backend as a service —so you can focus on developing a feature rich angular frontend back4app provides a fully managed nosql database, user authentication, cloud code for custom logic, and sdks for seamless integration this allows you to build and deploy scalable applications without managing server infrastructure key takeaways by following this tutorial, you will initialize a modern angular project using angular cli seamlessly integrate a backend service to manage your app’s data implement essential crud operations for a dynamic to do list deploy your fully functional application using containerized workflows on back4app prerequisites before you begin, ensure you have node js and npm installed on your machine verify installations with node v and npm v basic angular knowledge , including components, services, and dependency injection a back4app account to manage your backend services sign up at back4app https //www back4app com/ if you haven’t already with these prerequisites in place, you’re ready to start building your project project setup begin by setting up your local development environment and initializing a new angular project using angular cli ensure you have node js (lts version) installed if not, download it from nodejs org https //nodejs org/ install the angular cli globally if you haven’t already npm install g @angular/cli create a new angular project ng new todo app routing style=css navigate to your project directory cd todo app start the development server to verify the setup ng serve open http //localhost 4200 in your browser to see your angular app in action with the frontend ready, proceed to create your backend on back4app creating the todo backend back4app offers a fully managed backend service powered by parse , including a nosql database, authentication, cloud code, and auto generated apis follow these steps to set up your backend log in to your back4app dashboard https //www back4app com/ and click "create a new app " name your app (for example, todoapp ) and select nodejs/parse as the backend type navigate to "database" > "browser" , click "create a class" , and choose "custom" name the class task and set the permissions to allow public read and write (you can refine these later) in the task class, add the following fields title (string) – the title of the task description (string) – details about the task completed (boolean) – task completion status duedate (date) – the deadline for the task click "save" to create the schema integrating back4app with angular you will use the parse javascript sdk to connect your angular app to the back4app backend install the parse sdk npm install parse configure the sdk in your angular project open src/app/app module ts (or create a dedicated service) and initialize parse with your application id and javascript key from the back4app dashboard (found under app settings > security & keys ) for example, create a service parse service ts in the src directory import { injectable } from '@angular/core'; import parse from 'parse'; @injectable({ providedin 'root', }) export class parseservice { constructor() { const parse app id = "your application id"; const parse js key = "your javascript key"; parse initialize(parse app id, parse js key); (parse as any) serverurl = 'https //parseapi back4app com/'; } } then, in your components, simply inject parseservice in the constructor the service will run its constructor once (at the application startup), initializing parse for you with your backend connected, you can now build the to do list ui and implement crud operations developing the frontend your angular application will consist of components and services to add, display, update, and delete tasks you will leverage angular’s component architecture and dependency injection for smooth data management structuring your components generate the following components using angular cli ng generate component components/task form ng generate component components/task list ng generate component components/task item taskformcomponent this component renders a form for adding new tasks it captures user input and submits the task data to back4app add task // src/app/components/task form/task form component ts import { component, eventemitter, output } from '@angular/core'; import { formsmodule } from '@angular/forms'; import as parse from 'parse'; @component({ selector 'app task form', templateurl ' /task form component html', styleurls \[' /task form component css'], imports \[formsmodule] }) export class taskformcomponent { title = ''; description = ''; @output() refreshtasks = new eventemitter\<void>(); async onsubmit() { try { const task = parse object extend('task'); const task = new task(); task set('title', this title); task set('description', this description); task set('completed', false); await task save(); this refreshtasks emit(); this title = ''; this description = ''; } catch (error) { console error('error adding task ', error); } } } tasklistcomponent this component displays a list of tasks by iterating over an array and rendering each task using the taskitemcomponent no tasks available // src/app/components/task list/task list component ts import { component, input, oninit } from '@angular/core'; import { commonmodule } from '@angular/common'; import as parse from 'parse'; import { taskitemcomponent } from ' /task item/task item component'; @component({ selector 'app task list', templateurl ' /task list component html', styleurls \[' /task list component css'], imports \[commonmodule, taskitemcomponent] }) export class tasklistcomponent implements oninit { @input() tasks any\[] = \[]; @input() fetchtasks! () => void; ngoninit() void {} } taskitemcomponent this component represents an individual task and provides buttons to toggle completion status or delete the task {{ task title }} {{ task description }} {{ task completed ? 'undo' 'complete' }} delete // src/app/components/task item/task item component ts import { component, eventemitter, input, output } from '@angular/core'; import as parse from 'parse'; @component({ selector 'app task item', templateurl ' /task item component html', styleurls \[' /task item component css'] }) export class taskitemcomponent { @input() task any; @output() taskchanged = new eventemitter\<void>(); async togglecomplete() { try { const query = new parse query('task'); const tasktoupdate = await query get(this task id); tasktoupdate set('completed', !this task completed); await tasktoupdate save(); this taskchanged emit(); } catch (error) { console error('error updating task ', error); } } async deletetask() { try { const query = new parse query('task'); const tasktodelete = await query get(this task id); await tasktodelete destroy(); this taskchanged emit(); } catch (error) { console error('error deleting task ', error); } } } appcomponent integration in your main component, manage the state of tasks and integrate the task components to do list // src/app/app component ts import { component, oninit } from '@angular/core'; import { parseservice } from ' /parse service'; import as parse from 'parse'; import { taskformcomponent } from ' /components/task form/task form component'; import { tasklistcomponent } from ' /components/task list/task list component'; @component({ selector 'app root', imports \[taskformcomponent, tasklistcomponent], templateurl ' /app component html', styleurl ' /app component css' }) export class appcomponent implements oninit { constructor(private parseservice parseservice) {} tasks any\[] = \[]; async fetchtasks() { try { const task = parse object extend('task'); const query = new parse query(task); const results = await query find(); this tasks = results map(task => ({ id task id, task tojson() })); } catch (error) { console error('error fetching tasks ', error); } } ngoninit() void { this fetchtasks(); } } styling the application create or update the styles in your component css files or in src/styles css / src/styles css / container { max width 600px; margin 40px auto; padding 0 20px; text align center; font family sans serif; } h1 { margin bottom 20px; } form { display flex; flex direction column; align items center; gap 10px; margin bottom 20px; } form input\[type="text"] { width 80%; max width 400px; padding 8px; box sizing border box; font size 1rem; } form button { padding 8px 16px; cursor pointer; font size 1rem; border none; background color #eaeaea; transition background color 0 2s ease; } form button\ hover { background color #ccc; } task item { display flex; flex direction column; align items center; justify content center; gap 12px; border 1px solid #ccc; border radius 6px; padding 15px; margin 10px 0; background color #fafafa; text align center; transition background color 0 2s ease; } task item completed h3, task item completed p { text decoration line through; color #888; } task item h3 { margin 0; font size 1 1rem; } task item p { margin 0; font size 1rem; } task item button { padding 6px 12px; border none; background color #eaeaea; cursor pointer; font size 0 9rem; } task item button\ hover { background color #ccc; } @media (min width 600px) { task item { flex direction row; } } deploying the frontend on back4app web deployment back4app web deployment provides a containerized environment to host your angular application configuring angular for production build your production ready angular app ng build this command generates a dist/ folder containing your compiled angular app creating a dockerfile create a dockerfile in your project root with the following content from node 18 alpine as build workdir /app copy package json package lock json / run npm install g @angular/cli run npm install copy run ng build cmd \["ng", "serve", " host", "0 0 0 0"] testing the docker container locally build your docker image docker build t todo frontend run the container docker run p 4201 4200 todo frontend open http //localhost 4201 in your browser to verify that your angular app is served correctly deploying to back4app initialize a git repository, add your project files, and commit git init git add git commit m "initial commit for back4app deployment" git branch m main git remote add origin \<your github repository url> git push u origin main log in to back4app web deployment https //www back4app com/containers click "create new app" , provide your project name, and select your github repository authorize back4app and choose dockerfile deployment confirm the build settings and click "deploy" to start the deployment process monitoring your deployment after deployment, use the back4app dashboard to view logs for debugging monitor container performance and resource usage trigger rebuilds on new commits configure custom domains if needed access your live application at https //todoapp ku5ofg8s b4a run/ https //todoapp ku5ofg8s b4a run/ https //todoapp ku5ofg8s b4a run/ testing and debugging after deployment, confirm that your angular frontend communicates effectively with the back4app backend api verification use your browser’s developer tools (f12 → network) to inspect api requests task operations add, complete, and delete tasks via the ui and verify updates in the back4app database browser error handling check console logs for errors and test edge cases such as empty submissions performance testing simulate slow network conditions using browser tools to assess responsiveness best practices for using back4app with angular to optimize your application efficient requests use batch operations for handling multiple tasks const tasks = \[task1, task2, task3]; parse object saveall(tasks); optimized queries retrieve only the necessary fields query select('title', 'completed'); environment management store sensitive keys in environment variables ng app parse app id=your app id ng app parse js key=your js key security use acls to restrict data access task setacl(new parse acl(parse user current())); backend offloading leverage cloud code for complex logic to reduce frontend load conclusion you have now built a full stack to do list application by creating an angular frontend, integrating it with back4app’s backend, and deploying it using containerized workflows this tutorial guided you through every step—from local development to cloud deployment—ensuring robust interaction between your angular ui and backend services looking ahead, consider enhancements like real time updates, improved authentication, and third party integrations for further learning, visit the back4app documentation https //www back4app com/docs and explore community resources