Join Scott Gardner for an in-depth discussion in this video Delegation, part of Swift 3 Essential Training: Beyond the Basics.
- [Instructor] I'll continue to build upon the examples…in the playground I've used throughout this chapter.…I've added the definition of a Cart class…that has an items property defaulted to…an empty array of LineItemable and an addItem method.…A common design pattern found…in software engineering is delegation.…A type instance can hand-off, or delegate,…responsibilities to an instance of another type.…Protocols are a great way to specify…that a delegate can fulfill the responsibilities.…I want a Cart instance to be able to delegate…the responsibility of calculating a subtotal…of its items property, rather than including that logic…in the Cart class itself.…
This separation of concerns will help keep…the Cart class focused on just being a cart,…and not get bloated with extended responsibilities…to cater to the needs of a purchase transaction.…I'll define a CartDelegate protocol that requires…a subtotalFor items method.…Next, I'll define a calculator struct…that adopts and conforms to CartDelegate,…using the reduce method to sum…
- Adding source files, resources, links, and literals
- Adding pages to a playground
- Using overflow operators and bitwise operators
- Using ranges with strings
- Creating complex sequences
- Chaining higher-order functions
- Defining lazy properties
- Using failable initializers
- Mutating methods
- Working with singletons
- Nesting function types
- Creating error types and recursive enumerations
- Extending concrete types
- Referencing selectors and key paths
- Working with protocol-oriented programming
- Defining class-only protocols and optional protocols
- Using option sets, type checking, and casting operators
Skill Level Intermediate
Core Data for iOS and macOS Enterprise Developerswith Jon Bott1h 46m Intermediate
Distributing Your iOS App for Testing with TestFlightwith Ron Buencamino35m 10s Intermediate
iOS App Development: Test-Driven Developmentwith Harrison Ferrone2h 14m Intermediate
3. Strings and Characters
4. Sequences and Collections
5. Control Flow
6. Value and Reference Types
9. Access Control
Understand access control3m 47s
Next steps1m 2s
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.