phpGPX

Simple library written in PHP for reading and creating GPX files.

Library is currently marked as Release Candidate but is already used in production on several projects without any problems. Documentation is available using GitHub pages generated by Jekyll.

Contribution and feedback is welcome! Please check the issues for TODO. I will be happy every feature or pull request.

Repository branches:

• master: latest stable version
• develop: works on 2.x

Features

• Full support of official specification.
• Statistics calculation.
• Extensions.
• JSON & XML & PHP Array output.

Supported Extensions

• Garmin TrackPointExtension: http://www.garmin.com/xmlschemas/TrackPointExtension/v1

Stats calculation

• (Smoothed) Distance (m)
• Average speed (m/s)
• Average pace (s/km)
• Min / max altitude (m)
• (Smoothed) Elevation gain / loss (m)
• Start / end (DateTime object)
• Duration (seconds)

Installation

You can easily install phpGPX library with composer. There is no stable release yet, so please use release candidates.

composer require sibyx/phpgpx:@1.1.2

Examples

Open GPX file and load basic stats

<?php
use phpGPX\phpGPX;

$gpx = new phpGPX();
	
$file = $gpx->load('example.gpx');
	
foreach ($file->tracks as $track)
{
    // Statistics for whole track
    $track->stats->toArray();
    
    foreach ($track->segments as $segment)
    {
    	// Statistics for segment of track
    	$segment->stats->toArray();
    }
}

Writing to file

<?php
use phpGPX\phpGPX;

$gpx = new phpGPX();
	
$file = $gpx->load('example.gpx');

// XML
$file->save('output.gpx', phpGPX::XML_FORMAT);
	
//JSON
$file->save('output.json', phpGPX::JSON_FORMAT);

Creating file from scratch

<?php

use phpGPX\Models\GpxFile;
use phpGPX\Models\Link;
use phpGPX\Models\Metadata;
use phpGPX\Models\Point;
use phpGPX\Models\Segment;
use phpGPX\Models\Track;

require_once '/vendor/autoload.php';

$sample_data = [
	[
		'longitude' => 9.860624216140083,
		'latitude' => 54.9328621088893,
		'elevation' => 0,
		'time' => new \DateTime("+ 1 MINUTE")
	],
	[
		'latitude' => 54.83293237320851,
		'longitude' => 9.76092208681491,
		'elevation' => 10.0,
		'time' => new \DateTime("+ 2 MINUTE")
	],
	[
		'latitude' => 54.73327743521187,
		'longitude' => 9.66187816543752,
		'elevation' => 42.42,
		'time' => new \DateTime("+ 3 MINUTE")
	],
	[
		'latitude' => 54.63342326167919,
		'longitude' => 9.562439849679859,
		'elevation' => 12,
		'time' => new \DateTime("+ 4 MINUTE")
	]
];

// Creating sample link object for metadata
$link = new Link();
$link->href = "https://sibyx.github.io/phpgpx";
$link->text = 'phpGPX Docs';

// GpxFile contains data and handles serialization of objects
$gpx_file = new GpxFile();

// Creating sample Metadata object
$gpx_file->metadata = new Metadata();

// Time attribute is always \DateTime object!
$gpx_file->metadata->time = new \DateTime();

// Description of GPX file
$gpx_file->metadata->description = "My pretty awesome GPX file, created using phpGPX library!";

// Adding link created before to links array of metadata
// Metadata of GPX file can contain more than one link
$gpx_file->metadata->links[] = $link;

// Creating track
$track = new Track();

// Name of track
$track->name = "Some random points in logical order. Input array should be already ordered!";

// Type of data stored in track
$track->type = 'RUN';

// Source of GPS coordinates
$track->source = "MySpecificGarminDevice";

// Creating Track segment
$segment = new Segment();


foreach ($sample_data as $sample_point)
{
	// Creating trackpoint
	$point = new Point(Point::TRACKPOINT);
	$point->latitude = $sample_point['latitude'];
	$point->longitude = $sample_point['longitude'];
	$point->elevation = $sample_point['elevation'];
	$point->time = $sample_point['time'];

	$segment->points[] = $point;
}

// Add segment to segment array of track
$track->segments[] = $segment;

// Recalculate stats based on received data
$track->recalculateStats();

// Add track to file
$gpx_file->tracks[] = $track;

// GPX output
$gpx_file->save('CreatingFileFromScratchExample.gpx', \phpGPX\phpGPX::XML_FORMAT);

// Serialized data as JSON
$gpx_file->save('CreatingFileFromScratchExample.json', \phpGPX\phpGPX::JSON_FORMAT);

// Direct GPX output to browser

header("Content-Type: application/gpx+xml");
header("Content-Disposition: attachment; filename=CreatingFileFromScratchExample.gpx");

echo $gpx_file->toXML()->saveXML();
exit();

Currently, supported output formats:

• XML
• JSON

Configuration

Use the static constants in phpGPX to modify behaviour.

/**
 * Create Stats object for each track, segment and route
 */
public static $CALCULATE_STATS = true;

/**
 * Additional sort based on timestamp in Routes & Tracks on XML read.
 * Disabled by default, data should be already sorted.
 */
public static $SORT_BY_TIMESTAMP = false;

/**
 * Default DateTime output format in JSON serialization.
 */
public static $DATETIME_FORMAT = 'c';

/**
 * Default timezone for display.
 * Data are always stored in UTC timezone.
 */
public static $DATETIME_TIMEZONE_OUTPUT = 'UTC';

/**
 * Pretty print.
 */
public static $PRETTY_PRINT = true;

/**
 * In stats elevation calculation: ignore points with an elevation of 0
 * This can happen with some GPS software adding a point with 0 elevation
 */
public static $IGNORE_ELEVATION_0 = true;

/**
 * Apply elevation gain/loss smoothing? If true, the threshold in
 * ELEVATION_SMOOTHING_THRESHOLD and ELEVATION_SMOOTHING_SPIKES_THRESHOLD (if not null) applies
 */
public static $APPLY_ELEVATION_SMOOTHING = false;

/**
 * if APPLY_ELEVATION_SMOOTHING is true
 * the minimum elevation difference between considered points in meters
 */
public static $ELEVATION_SMOOTHING_THRESHOLD = 2;

/**
 * if APPLY_ELEVATION_SMOOTHING is true
 * the maximum elevation difference between considered points in meters
 */
public static $ELEVATION_SMOOTHING_SPIKES_THRESHOLD = null;

/**
 * Apply distance calculation smoothing? If true, the threshold in
 * DISTANCE_SMOOTHING_THRESHOLD applies
 */
public static $APPLY_DISTANCE_SMOOTHING = false;

/**
 * if APPLY_DISTANCE_SMOOTHING is true
 * the minimum distance between considered points in meters
 */
public static $DISTANCE_SMOOTHING_THRESHOLD = 2;

I wrote this library as part of my job in Backbone s.r.o..

License

This project is licensed under the terms of the MIT license.