ELLocation

ELLocation provides the ELLocation module.

ELLocation is intended to be a wrapper around iOS's location services. Its goal is to provide convenient and concise wrappers to access CLLocationManager and friends. ELLocation is also designed to work well with, and to utilize other libraries in TheHolyGrail, or THG for short.

A quick word about dependencies

ELLocation/ELLocation depends on ELFoundation/ELFoundation.

THG projects are designed to live side-by-side in the file system, like so:

• \MyProject
• \MyProject\ELFoundation
• \MyProject\KillerRabbit

Common Usage

ELLocation can be used for authorizing for location services and for setting up an object to receive location updates.

Authorization

Important Note: iOS requires that you add NSLocationWhenInUseUsageDescription and/or NSLocationAlwaysUsageDescription key to the Info.plist file for your app as per your needs. If you miss this step, nothing will work and there will be no message to indicate why.

iOS requires an app to request authorization from the user for the kind of location services it needs to use. With ELLocation the API looks like the following:

if let anError = LocationAuthorizationService().requestAuthorization(.WhenInUse) {
    //TODO: Client needs to process error and re-request auth
} else {
    startLocationUpdates()
}

Location Updates

In order for a caller to get location updates it must do the following:

func startLocationUpdates() {
    // Set up the request
    let request = LocationUpdateRequest(accuracy: .Good) { (success, location, error) -> Void in
        if success {
            if let actualLocation = location {
                print("LISTENER 1: success! location is (\(actualLocation.coordinate.latitude), \(actualLocation.coordinate.longitude))")
            }
        } else {
            if let theError = error {
                print("LISTENER 1: error is \(theError.localizedDescription)")
            }
        }
    }
    
    // Register the listener
    if let addListenerError = LocationUpdateService().registerListener(self, request: request) {
        print("LISTENER 1: error in adding the listener. error is \(addListenerError.localizedDescription)")
    } else {
        print("LISTENER 1 ADDED")
    }
}

Note that there can be an error in setting up the request and that is returned right away rather than in the handler block. You should check for that.

It is also possible to limit the callback frequency using the updateFrequency parameter of LocationUpdateRequest like so:

let request = LocationUpdateRequest(accuracy: .Good, updateFrequency: .ChangesOnly, ...)

Combining accuracy: .Coarse with updateFrequency: .ChangesOnly, along with requestAuthorization(.Always) yields the lowest battery usage, at the expense of less accurate location data and infrequent updates.

Contributions

We appreciate your contributions to all of our projects and look forward to interacting with you via Pull Requests, the issue tracker, via Twitter, etc. We're happy to help you, and to have you help us. We'll strive to answer every PR and issue and be very transparent in what we do.

When contributing code, please refer to our Dennis.

THG's Primary Contributors

Dr. Sneed (@bsneed)
Steve Riggins (@steveriggins)
Sam Grover (@samgrover)
Angelo Di Paolo (@angelodipaolo)
Cody Garvin (@migs647)
Wes Ostler (@wesostler)

License

The MIT License (MIT)

Copyright (c) 2015 Walmart, TheHolyGrail, and other Contributors

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.