UITableView + Cache

https://github.com/Kilograpp/UITableView-Cache

UITableView cell cache that cures scroll-lags on a cell instantiating.

Introduction

UITableView+Cache is a light UITableView category that purges scroll-lag that occurs on a new cell instantiation during scroll. It makes UITableView instantiate and cache cells before cellForRow:atIndexPath: call. It also provides simple interface very similar to existing registerClass/registerNib one.

Installation

CocoaPods

	pod 'UITableView+Cache'

Carthage

	github "Kilograpp/UITableView-Cache" "master"

Manual importing

Just add all files from src directory to your project.

Usage

When registering custom cells, call overriden registerClass/registerNib method instead of a default. UITableView+Cache swizzles dequeueReusableCellWithIdentifier methods with a private one that uses its own cache and implements registerClass/registerNib mechanism on itself. When dequeueReusableCellWithIdentifier is called and returns nil - the cache is asked for a cell. If cache is empty then cell is created using registered class or nib.

Swift 3

import UITableView_Cache

...

override func viewDidLoad() {
	super.viewDidLoad()

	self.tableView.registerClass(TableViewCodeCell.self, forCellReuseIdentifier: "MyReuseIdentifier", cacheSize: 10)
	self.tableView.registerNib(TableViewCodeCell.nib, forCellReuseIdentifier: "MyReuseIdentifier", cacheSize: 10)
}

...

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
	let cell = self.tableView.dequeueReusableCellWithIdentifier("MyReuseIdentifier") as! TableViewCodeCell
	return cell
}

Objective-C

- (void)viewDidLoad {
	[super viewDidLoad];

	[self.tableView registerClass:[TableViewCodeCell class] forCellReuseIdentifier:@"MyReuseIdentifier" cacheSize:10];
	[self.tableView registerNib:[TableViewNibCell nib] forCellReuseIdentifier:@"MyNibReuseIdentifier" cacheSize:10];
}

...

- (MyCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	MyCell* cell = [tableView dequeueReusableCellWithIdentifier:@"MyReuseIdentifier"];
	return cell;
}

Make sure to call dequeueReusableCellWithIdentifier:reuseIdentifier method and NOT dequeueReusableCellWithIdentifier:reuseIdentifier:forIndexPath: one. They perform different logic and a crash will occure on wrong method use.

Storyboards

Storyboards are not supported, cached cells should be registered from code. Nevertheless, if you strongly require storyboard usage then you could swizzle basic UITableView's registerNib/registerClass methods for your own and call. But I won't recommend this solution for it tampers UITableView mechanism.

Best Practises

As you know any cache consumes some memory. Best advice I could give is to keep track of your tableViews and free them as soon as possible. Having too many tableViews may cause memory pressure on your app.

License

UITableView+Cache is available under the MIT license. See the LICENSE file for more info.

Author

Mehdzor