Offline Content for iOS

Last updated: 6/14/2023

1. Developing on the new Arm-based Apple Silicon (M1) Macs requires building and running on a physical iOS device or using an iOS simulator running iOS 13.7, e.g. iPhone 11. This is a temporary limitation in Google Maps SDK for iOS, and as such also a limitation in MapsIndoors, due to the dependency to Google Maps.
2. Note: Due to a bug in CocoaPods it is necessary to include the post_install hook in your Podfile described in the PodFile post_install wiki.

Cacheable Data

MapsIndoors has three levels of caching:

1. Basic Data: All descriptions, geometries and metadata about POIs, rooms, areas, buildings and venues.
2. Detailed Data: The same as Basic Data, plus images referenced by the data.
3. Full Dataset: The same as Detailed Data, plus Map Tiles.

Full Dataset caching requires that Map Tiles are prepared specifically for this purpose. Contact MapsPeople in order to arrange this.

Automatic Caching

Out of the box, MapsIndoors automatically caches all basic data for the active dataset on the device, whereas images and Map Tiles are cached only as they are used.

This means all MapsIndoors-specific data is cached automatically, but images are only cached after they have been needed for map display. Likewise, Map Tiles are only cached when needed for map display, so all parts of the map that has been shown are cached. Areas and Zoom Levels that have not been shown as part of user interaction are not cached.

Tweaking Caching Behaviour

Applications have a few ways to change the default caching behaviour:

The synchronization process can be started manually:

MapsIndoors.synchronizeContent { (error) in
    ...
}

The level of caching can be changed:

let dataSetManager = MapsIndoors.dataSetCacheManager
let dataSet = dataSetManager.dataSetForCurrentMapsIndoorsAPIKey()
dataSetManager.setCachingScope(.cachingScope_Full, cacheItem: dataSet!.cacheItem)

Bundling of Data in the Application

If needed, it is possible to bundle one MapsIndoors dataset to make your app work better in offline or poor network conditions. Please note that while MapsIndoors content can be used offline, Google Maps does not provide offline features. Outdoor wayfinding and Google Places searches will be unavailable and the surrounding map may be unavailable unless it has been cached.

In your app targets build phases, add a "Run Script" build phase containing the following command:

${SRCROOT}/Pods/MapsIndoors/Scripts/derive_ressources.sh --api-key=YOUR_MAPSINDOORS_API_KEY --language=en

Replace:

• YOUR_MAPSINDOORS_API_KEY with your MapsIndoors API key.
• en with any one of the languages that your MapsIndoors Solution supports (Two letter ISO-639-1 language code). If you only have one language deployed you may remove this input parameter entirely

Depending on the overall size of your MapsIndoors deployment, this may take some time, so during development you might want to check the "Run script only when installing" option. This means that content will only be bundled when archiving for e.g. a release.

Caching of Multiple Datasets

Available in SDK version 3.9 and later

The most common use of MapsIndoors involves only one dataset, but for large deployments, data may be partitioned into multiple datasets.

Offline caching of multiple simultaneous datasets is fully supported, and is mostly limited by the available storage space on device.

NOTE: Only one dataset is active at any point in time.

Management of multiple datasets is done via MPDataSetCacheManager, which allows querying, adding, modifying and removing datasets.

Listing Managed Datasets

All datasets currently managed are accessible via the MapsIndoors.dataSetCacheManager.managedDataSets collection:

for ds in MapsIndoors.dataSetCacheManager.managedDataSets {
    print( "\(ds.name): size \(ds.cacheItem.syncSize)" )
}

This can be used to build a management user interface, and information about individual datasets can be accessed from the MPDataSetCache and MPDataSetCacheItem classes.

Adding Datasets for Offline Caching

Datasets are scheduled for caching using one of the MapsIndoors.dataSetCacheManager.addDataSet() variants:

MapsIndoors.dataSetCacheManager.addDataSet("API Key")
MapsIndoors.dataSetCacheManager.addDataSet("API Key", cachingScope: .cachingScope_Basic)

The current MapsIndoors API key is automatically added as a managed dataset with cachingScope_Basic.

Removing Datasets

Datasets are removed from caching using MapsIndoors.dataSetCacheManager.removeDataSet():

MapsIndoors.dataSetCacheManager.removeDataSet(MPDataSetCache)

NOTE: The currently active dataset is not removed.

Changing Caching Parameters

To change the extent of caching, for example in a management menu:

let dataSetManager = MapsIndoors.dataSetCacheManager
let dataSet = dataSetManager.dataSetForCurrentMapsIndoorsAPIKey()
dataSetManager.setCachingScope( .cachingScope_Detailed, cacheItem: dataSet?.cacheItem )

Determining the Caching Size of a Dataset

The estimated and cached size of a dataset is available via:

dataSet?.cacheItem.cachedSize
dataSet?.cacheItem.syncSize

To refesh or get the size of a synced dataset:

dataSetManager.fetchSyncSizes(for: [dataSet], delegate: self)

This is an asynchronous process, and a MPDataSetCacheManagerSizeDelegate is needed for getting information about progress and results.

Synchronizing Data with MPDataSetCacheManager

The MPDataSetCacheManagerallows for finegrained control which datasets are synchronized, and allows for cancellation:

// Sync allmanaged datasets:
dataSetManager.synchronizeContent()

// Synchronize specific datasets:
dataSetManager.synchronizeCacheItems([dataSet.cacheItem, ...])

// Cancellation:
dataSetManager.cancelSynchronization()