Question: What Is Datasource In Swift?

What is reuseIdentifier in Swift?

As per the Apple’s doc – reuseIdentifier is a string used to identify the cell object if it is to be reused for drawing multiple rows of a table view.

Pass nil if the cell object is not to be reused.

You should use the same reuse identifier for all cells of the same form.


What is data source in Swift?

To manage the data, you provide the table with a data source object—that is, an object that implements the UITableViewDataSource protocol. A data source object responds to data-related requests from the table. It also manages the table’s data directly, or coordinates with other parts of your app to manage that data.

What is Diffable data source?

Overview. A diffable data source object is a specialized type of data source that works together with your table view object. It provides the behavior you need to manage updates to your table view’s data and UI in a simple, efficient way.

How do delegates work in Swift?

A delegate is an object that acts on behalf of, or in coordination with, another object when that object encounters an event in a program. The delegating object is often a responder object–that is, an object inheriting from NSResponder in AppKit or UIResponder in UIKit–that is responding to a user event.

What is delegate and protocol in iOS?

Protocols are a way to specify a set of methods you want a class to implement if it wants to work with one of your classes. Delegates and Data Sources like UITableViewDelegate and UITableViewDataSource are protocols indeed. … You can also declare some optional methods by declaring them after the @optional specifier.

What are the methods of delegation?

Put these seven delegation strategies into practice and watch as your organization’s efficiency increases:Learn to let go. … Establish a firm priority system. … Play to your workers’ strengths. … Always include instructions. … Don’t be afraid to teach new skills. … Trust, but verify.More items…•May 7, 2015

What is reuse identifier in Xcode?

A reuse identifier is a string that you assign to each prototype cell of your table. In your storyboard, select your prototype cell and assign a nonempty value to its identifier attribute. Each cell in a table view must have a unique reuse identifier. … method, passing the reuse identifier for the cell you want.

How do you delegate in Objective C?

Objective C Delegation by ExampleCreate a protocol.Create a delegate property in the class that performs the assigned task.Once the task is complete, delegate property to be used to return the result.Implement the protocol.

What is datasource and delegate in Swift?

The data source provides information about what to display, like how many rows, and what goes in each row. The delegate tells the tableview what to do when the user selects a row, or whether the user is allowed to edit a row, and other things like that.

What is difference between delegate and datasource in IOS?

A data source is almost identical to a delegate. The difference is in the relationship with the delegating object. Instead of being delegated control of the user interface, a data source is delegated control of data.

What is UITableViewDelegate?

UITableViewDelegate is a protocol you implement on your class to receive UITableView events. … The UITableViewDelegate protocol declares a method that the delegate must implement to return a cell object that the table view uses when drawing a particular row.

Why delegates are weak in Swift?

With using lazy keyword we are not initializing delegate which means there is no memory leak right now. Let’s break that. Object will be created and there will be memory leak. … Therefore, if the object conforming to the protocol needs to be stored in a weak property then the protocol must be a class-only protocol.

What is difference between protocol and delegate in Swift?

Protocol is a set of methods (either optional or required) that would be implemented by the class which conforms to that protocol. While, delegate is the reference to that class which conforms to that protocol and will adhere to implement methods defined in protocol. Have a look at this Apple doc for more detail.

Why delegates are weak iOS?

For delegation patters in iOS, the delegated object is the parent, because there is no need for the delegate caller to exist without the delegated object. … When you define a delegate object as property, it’s used a weak reference in the object it is defined in(lets say A, i.e. the delegate object is a property of A).

What is delegate in Swift?

Delegation is used for everything from handling table view events using UITableViewDelegate , to modifying cache behavior using NSCacheDelegate . The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way.

What is dequeueReusableCell in Swift?

dequeueReusableCell(withIdentifier:) Returns a reusable table-view cell object located by its identifier. Availability. Declaration. Parameters. Return Value.

What is a delegate iOS?

Delegate is simply just a means of communication between objects of iOS applications. You can think delegation as a simple way of connecting objects and communicate with each other. In other words we can say that delegate allows one object to send message to other object when any event occurs.