Reactive Programming in iOS Using Combine Framework

Explore reactive programming as a declarative, data‑driven paradigm that uses observables, observers, and operators like map and merge to manage asynchronous data streams with immutability, using the Combine framework.

Overview of the Combine framework, a Swift-based declarative API for reactive programming with publishers, subscribers, and operators like map and filter, enabling readable asynchronous UI behavior.

Explore publishers, subscribers, operators, and subjects in the Combine framework, and learn how data streams emit, react, transform, and multicast for real-time UI updates.

Create and work with publishers in Combine, using just and sequence publishers, and subscribe with sink. Manage cancellables and transform outputs with map in a playground before integrating into apps.

Subscribe to publishers such as timer, device orientation, and notification center, and manage subscriptions with cancellables for text field changes while updating the UI on the main thread.

Manage subscription life cycles in Combine by creating a publisher, subscribing with sink, and canceling manually or on view disappear, using timer publishers and assign to update values.

Build a numbers publisher from an array, apply map and try map, and handle errors with catch and map error to demonstrate completion and subscription in the Combine framework.

Learn transformation operators in the Combine framework, including map, flatMap, and merge. See map square numbers, flatMap flatten inner publishers into characters, and merge combine two integer streams.

Explore filtering operations in Combine by applying filter, compactMap, debounce, and bounce on publishers, including even-number filtering, nil handling, and debounced input examples.

Explore combining operators in combine: use combine latest to merge latest values from publishers, zip to pair items, and switch to latest to swap inner publishers.

Explore error handling in the Combine framework, showing how to use catch, try map, and replace error to manage errors and return publishers, and how retry enables repeated attempts.

Explore how pass through subject and current value subject in combine work as publishers and subscribers, including sending values, subscribing with sink, and retaining the last value.

Create a custom subject in combine that emits only even integers by conforming to the subject protocol and wrapping a passthrough inner subject with an initial value.

Demonstrates using a pass through subject in a weather client to publish updates and subscribe to values, simulating network delay with random weather data in a reactive Combine workflow.

Leverage combine to fetch posts from json placeholder, map and decode to post objects, receive on the main thread, and store the subscription in cancellables.

Explore error handling in iOS reactive programming with Combine: catch and throw custom errors, use tryMap to validate HTTP responses, and implement retries (three times) to recover from server failures.

Learn to combine two network requests in Swift using Combine's combineLatest, fetching Batman and Spider-Man movies from IMDb, decoding results, and managing publishers with type erasure and cancellables.

Sign up for an IMDb API key and learn to use the endpoints to search movies by keyword or title, retrieving title, year, IMDb ID, type, and poster.

Explore the starter UIKit project with a programmatic interface, a search bar, and a movie table view, previewing the UIKit view controller in Xcode.

Define a movie model and a movie response to map the IMDb JSON, aligning the top-level search array with an array of movies using custom coding keys.

Create an HTTP client using Combine to fetch movies by search, encoding the query, and returning a publisher of movie arrays.

Create a movie list view model in a MVVM UIKit app using Combine to fetch movies via an Http client, publish the results, and manage subscriptions with cancellables.

Integrate movie list view model with movies view controller via dependency injection and an http client, then debounce search bar input with combine publishers and refresh on loading completed.

Create a search publisher in the movie list view model using a current value subject, debounce 0.5 seconds, and sink to load movies after typing pauses.

Explore the starter project for reactive programming in iOS with Combine, reviewing the HTTP client fetch movies, movie model with poster URL and identifiable conformance, and upcoming content view setup.

Create a reactive SwiftUI movie list with state for movies and search terms, display posters via async image, add a searchable bar in a navigation stack, and inject an httpClient.

Create a current value subject as the search publisher, use onchange to publish input, debounce 0.5 seconds on the main thread, subscribe, and load movies via fetch.

Create a custom operator by extending the publisher to filter even numbers, returning any publisher. Use Xcode playgrounds and Combine to test, subscribe with sink, and observe the results.

Learn to create custom operators with parameters in the Combine framework, using a numbers greater than filter that accepts a threshold and works with map, flatMap, and retry.

Build a custom combine operator named map and filter by composing existing map and filter on publishers. Use closures to transform and filter, then erase to any publisher.

Learn practical debugging techniques for Combine pipelines in iOS, using print, breakpoints, and handle events to visualize the lifecycle of map and filter operations and the final sink.

Test reactive programming in iOS using the Combine framework by writing a basic XCTest in a playground to verify a just publisher emits a value, using an expectation and timeout.

Demonstrates integration testing of the Http client by fetching movies from a real service, using a unit test without mocks, with expectations and cancellables to handle async results.