CoreGPX 0.9.0

CoreGPX 0.9.0

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Maintained by Vincent Neo.

CoreGPX 0.9.0

Parse and generate GPX files easily on iOS, watchOS & macOS.

What is CoreGPX?

CoreGPX is a port of iOS-GPX-Framework to Swift language.

CoreGPX currently supports all GPX tags listed in GPX v1.1 schema. It can generate and parse GPX v1.1 compliant files on iOS, macOS and watchOS.

As it makes use of XMLParser for parsing GPX files, CoreGPX is fully dependent on the Foundation API only.

Features

  • Successfully outputs string that can be packaged into a GPX file
  • Parses GPX files using native XMLParser
  • Support for iOS, macOS & watchOS
  • (new) Supports Codable in essential classes
  • (new) Enhanced full support for GPXExtensions for both parsing and creating.
  • (new) Lossy GPX compression. Check out GPXCompressor for an implementation of this new feature.

Documentation

CoreGPX is documented using jazzy.

Documentation Status

You can read the documentation here, which documents most of the important features that will be used for parsing and creating of GPX files.

Installation

CoreGPX supports CocoaPods, Carthage, as well as Swift Package Manager, such that you can install it, any way you want.

To install using CocoaPods, simply add the following line to your Podfile:

pod 'CoreGPX'

CoreGPX works with Carthage as well, simply add the following line to your Cartfile:

github "vincentneo/CoreGPX"

How to parse?

Parsing of GPX files is done by initializing GPXParser.

There are five ways of initializing GPXParser, and these are three main ways of initializing:

You can initialize with a URL:

guard let gpx = GPXParser(withURL: inputURL)?.parsedData() else { return }

With path:

guard let gpx = GPXParser(withPath: inputPath)?.parsedData() else { return } // String type

With Data:

let gpx = GPXParser(withData: inputData).parsedData()

.parsedData() returns a GPXRoot type, which contains all the metadata, waypoints, tracks, routes, and extensions(if any), which you can expect from a GPX file, depending on what that file contains.

Making use of parsed GPX data

guard let gpx = GPXParser(withURL: inputURL)?.parsedData() else { return // do things here when failed }
        
// waypoints, tracks, tracksegements, trackpoints are all stored as Array depends on the amount stored in the GPX file.
for waypoint in gpx.waypoints {  // for loop example, every waypoint is written
    print(waypoint.latitude)     // prints every waypoint's latitude, etc: 1.3521, as a Double object
    print(waypoint.longitude)    // prints every waypoint's longitude, etc: 103.8198, as a Double object
    print(waypoint.time)         // prints every waypoint's date, as a Date object
    print(waypoint.name)         // prints every waypoint's name, as a String
}
    print(gpx.metadata?.desc)    // prints description given in GPX file metadata tag
    print(gpx.metadata?.name)    // prints name given in GPX file metadata tag

How to create?

You will first start off with a GPXRoot.

Initializing GPXRoot

let root = GPXRoot(creator: "Your app name here!") // insert your app name here

Now, you can start adding things to your GPXRoot. This includes your metadata, waypoints, tracks, routes, as well as extensions(if any).

Adding waypoints to GPXRoot

root.add(waypoints: arrayOfWaypoints) // adds an array of waypoints
root.add(waypoint: singleWaypoint)    // adds a single waypoint

Adding tracks to GPXRoot

root.add(tracks: arrayOfTracks)       // adds an array of tracks
root.add(track: singleTrack)          // adds a single track

Adding routes to GPXRoot

root.add(routes: arrayOfRoutes)       // adds an array of routes
root.add(route: singleRoute)          // adds a single route

Adding metadata to GPXRoot

let metadata = GPXMetadata()
metadata.name = "Your Name Here"
metadata.desc = "Description of your GPX file"
root.metadata = metadata              // adds metadata stuff

Example of application of GPXRoot

let root = GPXRoot(creator: "Your app name here!")
var trackpoints = [GPXTrackPoint]()

let yourLatitudeHere: CLLocationDegrees = 1.3521
let yourLongitudeHere: CLLocationDegrees = 103.8198
let yourElevationValue: Double = 10.724

let trackpoint = GPXTrackPoint(latitude: yourLatitudeHere, longitude: yourLongitudeHere)
trackpoint.elevation = yourElevationValue
trackpoint.time = Date() // set time to current date
trackpoints.append(trackpoint)

let track = GPXTrack()                          // inits a track
let tracksegment = GPXTrackSegment()            // inits a tracksegment
tracksegment.add(trackpoints: trackpoints)      // adds an array of trackpoints to a track segment
track.add(trackSegment: tracksegment)           // adds a track segment to a track
root.add(track: track)                          // adds a track

print(root.gpx())				// prints the GPX formatted string

This would be what you get from root.gpx() in the above example:

<?xml version="1.0" encoding="UTF-8"?>
<gpx xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.topografix.com/GPX/1/1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd" version="1.1" creator="Your app name here!">
	<trk>
		<trkseg>
			<trkpt lat="1.352100" lon="103.819800">
				<ele>10.724</ele>
				<time>2019-02-12T05:38:19Z</time>
			</trkpt>
		</trkseg>
	</trk>
</gpx>
  • .gpx() of GPXRoot outputs a String which can then be packaged as a .GPX file.
  • .OutputToFile(saveAt:fileName:) directly saves GPX contents to a URL specified.

Dealing with Extensions

Extensions in GPX files are represented as GPXExtensions in CoreGPX.

Accessing GPX Files's extensions

Once a GPX file is parsed, you can access the extensions, by using subscript, with the tag name.

  • Use extensions["tagNameHere"] to get a GPXExtensionElement, which will contain various data parsed. Alternatively, use get(from parent: String?) to get a dictionary of extension data parsed.

Writing GPX extensions

  • Firstly, initialize GPXRoot using init(withExtensionAttributes:, schemaLocation:) to initialize with extension schema information on the main gpx header tag.
  • Secondly, initialize GPXExtensions whenever needed, to be added to the GPXRoot/or other elements, when needed.
  • Use function append(at parent: String?, contents: [String : String]) to write extension data. If no parent, use nil.

To know more, please do read the documentation for GPXExtensions and GPXExtensionsElement.

Example

To know in depth of what CoreGPX can bring, do check out the Example app. To run the example project, simply clone the repo, and try it out straight away!

Contributing

Contributions to this project will be more than welcomed. Feel free to add a pull request or open an issue. If you require a feature that has yet to be available, do open an issue, describing why and what the feature could bring and how it would help you!

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License

CoreGPX is available under the MIT license. See the LICENSE file for more info.