SwiftSimpleMemo

Swiftsimememo? ️

Simple Memo App with Uikit & Swiftui

Todo

Basic function

• Memo list
• Notice registration
• Delete notes
• Memo modification
• Storage storage
• Note sharing

Additional function

• Image Notes Registration
• Image implementation in the detail view of the image
• Memo alignment
  
  

Today I learned

• Data renewal

  • ViewController Method viewWillAppear -In the sheet form that supports from iOS13 to default, it cannot be used.
  • Notification (observer pattern)

• If there is a place that does not give constraint in Storyboard, a red line will appear.

• Core data

  • Framework for preserving and caching data inside the terminal

  • Tasks that cause UI blocks can be run in the background

  • Helps to match the view between the view (table view, collection view, etc.) and the data

  • It is easy to create data crud without the need for DB management and easy for version management.

  • Core Data Stack

    • There are several classes that can be managed after creating the Core Data Model, which is called the Core Data Stack.
    • One class with NSPersistentContainer model, context, coordinator

• Delegate

  • DELEGATION is a design pattern that allows a class or structure to hand over part of the responsibility to another instance.
  • How to implement delegate
    • Storyboard
    • Protocol expansion through extension

• Escaping Closure (Swift)

  • The function delivered as the argument of the function is returned and the scope disappears, but the scope is escaping and stored in the outer variable even after the function ends.
    For example, use an escape closure when receiving the completed handler as an argument that is executed when it is completed after the asynchronous work processing.
  • If you refer to self in the escape closure, the self must be explicitly displayed or included in the capture list. In addition, in the case of the escape closure, the Weak Reference should be included in the capture list so that the memory rick does not occur due to strong reference.

• Strong reference cycle (swift)

  • Even if the variable is declared as NIL by strong reference between two or more instances, the ARC is not 0, so the memory leak is generated without being released.

  • Solution

    1. Use weak reference
       Variables or properties allocated before declaring weak keywords have a weak reference, so when you declare a variable that strongly refer to that instance as NIL, the ARC can be released without stopping.

    2. Use of smile
       Unlike the Weak Reference, it is used in the same or longer than the life of an instance. Unlike weak reference, it is used when it is expected to always refer to the value.