Angular HTTP Communication

Create an Angular application using the CLI, enable routing and SCSS styling, open the project in code, and prepare to configure HTTP requests for communication.

Configure the Angular app to start making ecb requests by importing the scdp client module from Angular common edp and updating the app to use the smb client module.

Import the ACP client module from Angular common EDP into the app's main module to enable HTTP calls.

Discover how Angular services centralize data requests for multiple components, using a single user service to fetch a list of users and individual user data.

learn to generate an angular service with the cli, place it in a service folder, and inject the httpclient in the root-provided user service for backend requests.

Import http client from Angular common and inject it into the user service via a private constructor parameter. This makes the http client a class member, showing Angular dependency injection.

Import the http client from the same module and inject it into the class via a private constructor parameter, then access it with this to build back end requests.

Learn how to use the Angular http client in a service to make get requests, returning an observable of either a user array or a single user with typed data.

Learn to use the json placeholder api for testing and prototyping, explore resources like posts, comments, albums, photos, todos, and users, and work with the users endpoint.

Implement a get users function in the user service returning an observable of user array via http get to a json placeholder, and add a get user function by id.

Map the HTTP response by defining nested interfaces for user, address, geo, and company to enable proper serialization and intellisense, using transform tools and angular Seelie.

Understand how observables emit data via subscribers and subscriptions without blocking, using next, error, and complete callbacks. Subscribe to trigger execution and handle the ECB response, including error handling.

Learn to inject a user service, call get users, and subscribe to observables in ngOnInit to retrieve and log user data from an API.

Set up an environment variable to manage the api base url for development and production, and inject it into the service for consistent, configurable http requests.

Learn how to implement post requests to create resources on a server by sending a payload, handling the response with an id, and understanding API documentation.

Learn to implement a post request to create a user by posting a user payload, using an observable, and handle an optional id as the server generates it.

Implement a put request in Angular HTTP communication by sending the entire user data, including ID and updated fields, and contrast it with patch behavior.

Learn to perform a PUT request in Angular to update a user by copying the create function, sending a body and the user id, and verifying with a fake API.

Explore how to use Angular HTTP patch to update only the changed fields by resource id, leaving other data intact, unlike put which requires the full payload.

Learn to use patch requests for partial updates in angular http communication, sending only the properties to change (name, email, username) via the user id.

Implement a delete request in an Angular service by passing the resource id, handling a void response, and confirming an HTTP 200 status from the server.

Implement a delete request for a user by ID, handle void responses, log results, and verify a 200 OK with an empty body.

Learn how http headers let the client and server exchange information during requests and responses in Angular, including content-type, authorization, and the HttpHeaders class for setting, appending, and deleting headers.

Learn how to configure HTTP headers in Angular's HttpClient, create and mutate headers immutably, and use set and append, then verify headers in the browser network tab.

Explore HTTP query parameters in Angular, using key-value pairs to filter data, control pagination (page, size), and pass additional info in requests, with built-in HTTP params helpers.

Explore configuring http parameters in Angular by using set, append, and immutable read-only maps, and learn to use from object and from string helpers to build query strings.

Explore how the Angular HttpClient observe options vary between returning events, the full http response, or just the body, and see how this helps with uploading files by tracking progress.

Learn how to upload files with angular http by observing and reporting progress for large data transfers, handling multipart form data, and streaming http events from client to a backend.

Create a file upload workflow in Angular by wiring an input type file to a change event, collecting selected files, sending them via form data, and tracking upload progress.

Develop a dynamic file upload progress bar in Angular by binding a percentage to upload events, calculating progress from loaded and total, and updating the UI from progress to done.

Learn to handle different response types in Angular HTTP calls, including JSON, text, and blob, and configure response type options for text and binary downloads.

Explore handling http responses in Angular by subscribing to requests, manipulating the returned data with reactive programming, and passing it to the user interface component.

Understand reactive programming as code that reacts to a data stream, where observables emit data to observers via subscriptions, enabling asynchronous server responses without blocking.

Discover RxJS as a JavaScript library for reactive programming in Angular, using observables and operators to manipulate data streams from asynchronous responses and events.

Learn how to use the tap operator in angular http communication to peek at data emitted by an observable via pipe, log values, and debug without altering the stream.

Learn how to use the map operator in Angular HTTP to transform API data on the client, such as uppercasing user names before presenting them in the user interface.

Use the map operator to transform incoming data by adding derived attributes like is admin and user id, and reshape objects to include only email, id, and website.

Set a default user image using robo hash, add an optional image attribute, and lowercase the user name to fetch and display a random robot image in the UI.

Apply the map operator inside pipe to transform http response data, whether a single user or an array, by returning a new object with isAdmin and a search key.

Explore the retry operator in Angular HTTP communication, retrying up to three times before failing, and learn how observables, pipe, and share replay caching help avoid backend flooding.

Develop robust error handling for http requests by using catch and throw or catch and replace, providing default or local data and messages when an observable errors.

Demonstrates the catch and release approach in Angular HTTP by using pipe operator to catch errors and return a fallback observable such as a John Doe user when fetch fails.

Learn to handle http request errors in Angular by using catch error in a pipe to replace failures with a fallback observable, returning an empty array or a default value.

Use the catch error with the pipe operator to intercept data retrieval, pass the error to an error function after manipulation, and emit a single error that completes the observable.

Master Angular HTTP communication by using catchError to intercept errors, manipulate the error payload, and return a custom object or message (such as 404 not found) to inform the user.

Discover how http interceptors in angular sit between your app and the internet to modify requests and responses, enabling security tasks like adding authorization headers and shaping payloads.

Learn to create an HTTP interceptor in Angular using the CLI or manual file creation, place it in an interceptor folder, and use it to intercept SCDP requests.

Implement an Angular http interceptor by registering it in the module’s providers, clone immutable requests, inject an api key header or token, and optionally modify the body or handle errors.

Continue learning and practice to become a software developer, building real-world Angular projects and small features to apply concepts, while using free courses and online communities to grow.