What is a Diffable data source?

What is a Diffable data source?

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. Generate the current state of the data.

When would you use a Diffable data source?

A diffable data source is an object that replaces your table view’s current UITableViewDataSource object. This means that it will supply your table view with the number of sections and items it needs to render, and it supplies your table view with the cells it needs to display.

What is swift UICollectionView?

The Collection View provides a flexible way to present content to the user. Similar to a table view, a collection view gets data from custom data source objects and displays it using a combination of cell, layout, and supplementary views.

What is collection reusable view?

This class is like UICollectionViewCell , except it’s usually used to display headers and footers. Like cells, UICollectionView places them in a reuse queue rather than deleting them when they scroll out of the visible bounds.

What is collection view layout?

This object manages the layout information for an item inside of a collection view. Layout objects (like cells) should create instances of this object when the collection view asks them to do so. Then, the collection view uses that information to position cells and supplementary views, if provided.

What is Table View delegate?

func tableView(UITableView, willDisplay: UITableViewCell, forRowAt: IndexPath) Tells the delegate the table view is about to draw a cell for a particular row.

What is difference between Tableview and collection?

Collection view can represent cells in multiple columns and rows. Table view presents data in multiple rows arranged in a single column, the cell design is fit as a row. However, collection view can create rows and columns, it can design cells in various ways, even if they are not necessarily rows.

How does swift implement UICollectionView?

The main steps of creating your first UICollectionView based screen are these:

1. Drag a UICollectionView object to your view controller.
2. Set proper constraints on the collection view.
3. Set dataSource & delegate of the collection view.
4. Prototype your cell layout inside the controller.

Which class object is used to manage data and provide cells for a collection view?

UICollectionView
An object that manages an ordered collection of data items and presents them using customizable layouts.

What are the two common collection view layout types?

There are two general types of collection view layouts:

• Layouts whose computations are independent of the content. This is the “simple” case you know from UITableView and UICollectionViewFlowLayout .
• Layouts that need to do content-dependent computations. Our calendar view is an example of this type.

How do I set collection view layout?

Open the Storyboard, select the collection view in the attributes inspector change the layout from flow to custom. Below the layout field a new field will appear where you can set the class. Type the name of our subclass. Now open the ViewController.

When to use a diffable data source in an app?

Using a diffable data source in your apps. Some best-practices to consider when using a diffable data source. By the end of this article, you will know exactly how to use diffable data sources and what their caveats are. A diffable data source is an object that replaces your table view’s current UITableViewDataSource object.

What does nsdiffabledatasourcesnapshot reference in diffable data source?

NSDiffableDataSourceSnapshot stores your sections and items, which the diffable data source references to understand how many sections and cells to display. Just like you created a type alias for UICollectionViewDiffableDataSource, you can create a Snapshot type alias as well.

Which is the generic type for uitableviewdiffabledatasource?

The UITableViewDiffableDataSource class has two generic types, one for the section identifier and one for the item. Both are constrained so that whatever type fills the generic type must conform to Hashable. If you’re not familiar with generics, check out this post I wrote as an introduction to generics in Swift.

What does diffable mean in the collection view?

The diffable part of UICollectionViewDiffableDataSource means that whenever you update the items you’re displaying, the collection view will automatically calculate the difference between the updated collection and the one previously shown.