JGCustomTileOverlay

A custom tile overlay implementation for MKMapKit that uses a local cache to store downloaded tiles. It is used into my app GPX viewer.

App and classes description

The app is an example of JGCustomTileOverlay usage. It displays a map that use this overlay to load tiles. You can access options from top right button, as clearing cache.

Classes :

• ViewController contains UI : map and options button. Check here how I initialize JGCustomTileOverlay and add it to mapView.

• CacheDirectoryManager Singleton class used to manage cache directory where tiles are stored. It provides methods to help using cache directory. If you want to change where tiles are stored, just change it in this class.

• JGCustomTileOverlay contains method to load each tile from cache (if it exists already) or load it from URL (and save it into cache).

Discussion about cache

Cache is stored into Application Support directory so it is managed by user. In GPX viewer, I need that downloaded tiles are not randomly deleted by iOS because user needs them for hiking. However, if you don't need to keep downloaded tiles, you can simply change cache directory.

Don't forget to ...

• Add Allow Arbitrary Loads to YES into App Transport Security Settings in your Info.plist to allow your custom URL template to be loaded.

• Import invalidTile.png in your project. It is displayed when URL template is invalid.

Any suggestions?

As this class is used into my production app GPX viewer, be free to contact me if you have any suggestions how to improve it.