Build Instagram to Master Swift 4 and Firebase

Install and integrate Firebase into an iOS app by creating a Firebase project, adding the iOS app with its bundle ID, configuring CocoaPods, and initializing Firebase in the app delegate.

Learn to enable email sign-in with Firebase authentication, install the Firebase auth library, create users via email and password, and switch to the tab bar after successful authentication.

Sign up new users with firebase authentication by reading email and password from text fields, and store username and email under the firebase user ID in the real-time database.

Validate sign up inputs and disable the sign up button until username, email, and password are non empty, then implement a set user information method to push data to database.

Learn to log users out and enable auto sign-in with Firebase authentication by checking the current user and presenting the sign-in view when needed.

Learn to add captions to posts and save them to the database. Enable the share button only with a photo, then clear inputs and reset the selected image after sharing.

Grab post data from the Firebase database and display it in the home table view by observing child added events and using data snapshots.

Design the home view for an Instagram-style app. Build a prototype post cell in a storyboard, including profile photo, username, post image, and reaction icons, with auto layout constraints.

Design a comment view with a storyboard and a table view that displays comments in dynamic cells, featuring a profile image, username, and comment, all managed within a navigation controller.

Toggle the keyboard with the command key, push the comment field and send button up by adjusting the bottom constraint to the keyboard height, then revert it when it hides.

Create post, user, and comment API classes to observe Firebase data; use a shared API struct for reusable instances, improving flexibility and scalability.

Apply a scalable like system using firebase transaction block to handle concurrent likes, update the post's like count and likes list, and reflect changes in real time.

Decouple views from the database by using a user api observer and current user fetch, feeding header views with safely unwrapped user data. Implement optional chaining to handle asynchronous fetches.

Discover users to follow by designing a discovery view with a table listing profiles, a navigation bar button to access it, and dynamic usernames drawn from the database.

Implement a follow and unfollow button that updates the database via a follow API, observes user relationships, and synchronizes the UI state with cached data.

Observe the database to keep follow states fresh during scrolling, avoiding stale cached data, and update the user object immediately after follow or unfollow to reflect the correct button state.

Update like information efficiently by caching a post object in the controller and passing it by reference to cells, ensuring up-to-date ui without database observers.

Learn to display the news feed by mirroring posts in a feed database and querying it for the home view, with follow and unfollow updates.