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Angular Glossary

A comprehensive reference of Angular terms, concepts, and definitions to support your learning journey.

A

Angular CLI Command Line Interface tool for Angular development. Provides commands to create, build, test, and deploy Angular applications.

Angular Material Official UI component library for Angular applications, implementing Google's Material Design.

AOT (Ahead-of-Time) Compilation Compilation process that converts Angular templates and components into JavaScript during the build process, rather than in the browser.

APP_INITIALIZER Injection token that provides functions to run during application initialization.

Architecture The structural design of an Angular application, including how components, services, and modules are organized.

B

Bootstrap The process of starting an Angular application. Also refers to the root component that gets loaded first.

Bundle A JavaScript file that contains compiled application code, created during the build process.

BehaviorSubject A type of RxJS Subject that stores the current value and emits it to new subscribers immediately upon subscription.

C

Change Detection Angular's mechanism for detecting and updating the DOM when application state changes.

Component A class with a template that controls a portion of the screen. The basic building block of Angular applications.

Constructor A special method in TypeScript/JavaScript classes that runs when an instance is created. Used for dependency injection in Angular.

Content Projection The pattern of inserting or projecting content from a parent component into a child component's template using ng-content.

Custom Element Angular components that can be used as custom HTML elements, useful for integration with non-Angular applications.

D

Data Binding The mechanism that coordinates communication between a component's template and its logic.

Decorator A function that modifies a class, property, method, or parameter. Angular uses decorators like @Component, @Injectable, etc.

Dependency Injection (DI) A design pattern and mechanism for creating and delivering dependencies to classes that need them.

Directive A class that can modify the structure or behavior of DOM elements. Angular has structural and attribute directives.

DOM (Document Object Model) A programming interface for HTML documents, representing the page structure as objects.

E

Element Reference (ElementRef) A wrapper around a native DOM element that can be used in Angular components.

Event Binding A form of data binding that listens to DOM events and executes component methods in response.

Event Emitter A class used to emit custom events from components, typically used with @Output() decorator.

F

Feature Module An Angular module that organizes related functionality, typically around a specific feature or business domain.

FormBuilder A service that provides convenient methods for creating form controls, groups, and arrays.

FormControl A class that tracks the value and validation status of an individual form input.

FormGroup A class that tracks the value and validity state of a group of form controls.

G

Guard An interface that can control navigation to and from routes. Types include CanActivate, CanDeactivate, etc.

Global Styles CSS styles that apply to the entire application, typically defined in styles.css.

H

Host Binding A decorator that binds a host element property to a directive or component property.

Host Listener A decorator that listens to events on the host element of a directive or component.

HTTP Client Angular's service for making HTTP requests to external APIs and servers.

HTTP Interceptor A service that can intercept and modify HTTP requests and responses.

I

Injection Token A token that can be used as a key for dependency injection when the dependency is not a class.

Injectable A decorator that marks a class as available for dependency injection.

Input A decorator that binds a component property to receive data from a parent component.

Interpolation A form of data binding that displays component data in the template using double curly braces {{ }}.

J

JIT (Just-in-Time) Compilation Compilation process that converts templates and components into JavaScript in the browser at runtime.

L

Lazy Loading A technique for loading modules only when they are needed, improving application startup performance.

Lifecycle Hooks Methods that tap into key moments in a component's lifecycle, such as ngOnInit, ngOnDestroy, etc.

M

Module A class decorated with @NgModule that organizes an application into cohesive blocks of functionality.

Multi-Provider A type of provider configuration that allows multiple values to be injected for a single token.

N

ng-content A directive used for content projection, allowing parent components to insert content into child component templates.

ng-container A grouping element that doesn't interfere with styles or layout because Angular doesn't put it in the DOM.

ng-template A template element that defines a template that is not rendered by default but can be instantiated elsewhere.

NgModule A decorator that defines a module, specifying which components, directives, and pipes belong to it.

NgRx A popular state management library for Angular applications based on Redux patterns.

O

Observable A representation of a stream of data that can be observed over time. Central to reactive programming in Angular.

OnPush A change detection strategy that only checks a component when its inputs change or an event is triggered.

Output A decorator that allows a component to emit events to parent components.

P

Pipe A simple way to transform displayed values within a template. Can format data like dates, currency, etc.

Property Binding A form of data binding that sets an element property to a component property value.

Provider Configuration that tells the injector how to create instances of dependencies.

R

Reactive Forms A model-driven approach to handling form inputs whose values change over time.

Resolver A service that retrieves data before navigation to a route is complete.

Router The Angular service responsible for navigation between views/components in single-page applications.

Router Outlet A directive that acts as a placeholder for routed components.

RxJS A library for reactive programming using Observables, heavily used throughout Angular.

S

Service A class that provides functionality that can be shared across components. Usually decorated with @Injectable.

Standalone Component A component that doesn't need to be declared in an NgModule and can be used directly.

Subject A special type of Observable that allows values to be multicasted to many Observers.

Subscription An object that represents the execution of an Observable and can be used to cancel that execution.

T

Template The HTML with Angular markup that defines how a component's view is rendered.

Template Reference Variable A variable that references a DOM element or component instance within a template.

Tree Shaking A build optimization technique that removes unused code from the final bundle.

TypeScript A superset of JavaScript that adds static type definitions, used as the primary language for Angular development.

U

Universal Angular technology for server-side rendering (SSR) of Angular applications.

Unsubscribe The process of canceling an Observable subscription to prevent memory leaks.

V

ViewChild A decorator that configures a view query to find the first element matching the selector.

ViewChildren A decorator that configures a view query to find all elements matching the selector.

ViewEncapsulation An enum that defines how component styles are encapsulated and applied.

Virtual Scrolling A technique for efficiently displaying large lists by only rendering visible items.

W

Web Components A set of web platform APIs that allow you to create custom, reusable HTML elements.

Webpack A module bundler used by Angular CLI to bundle application files for deployment.

Z

Zone.js A library that patches asynchronous operations to help Angular know when to trigger change detection.

Quick Reference

Common Decorators

  • @Component - Defines a component
  • @Injectable - Marks a class as injectable
  • @Input() - Receives data from parent
  • @Output() - Emits events to parent
  • @ViewChild - References template elements
  • @HostListener - Listens to host events

Lifecycle Hooks

  • ngOnInit - Component initialization
  • ngOnDestroy - Component cleanup
  • ngOnChanges - Input property changes
  • ngAfterViewInit - View initialization complete
  • ngDoCheck - Custom change detection

Common RxJS Operators

  • map - Transform emitted values
  • filter - Filter emitted values
  • switchMap - Switch to new Observable
  • mergeMap - Merge multiple Observables
  • catchError - Handle errors
  • takeUntil - Complete when another Observable emits

Angular CLI Commands

  • ng new - Create new project
  • ng generate - Generate code
  • ng serve - Start development server
  • ng build - Build project
  • ng test - Run unit tests
  • ng e2e - Run end-to-end tests

This glossary is continuously updated as new Angular features and concepts are introduced in the course.