v2

GBFS

Go implementation of client, server for GBFS (General Bikeshare Feed Specification).

Usage

Client

import "github.com/petoc/gbfs/v2"

c, err := gbfs.NewClient(gbfs.ClientOptions{
    AutoDiscoveryURL: "http://127.0.0.1:8080/v2/system_id/gbfs.json",
    DefaultLanguage:  "en",
})
if err != nil {
    log.Fatal(err)
}

Get single feed

f := &gbfs.FeedSystemInformation{}
err := c.Get(f)
if err != nil {
    log.Println(err)
}
if f.Data != nil {
    log.Printf("feed=%s system_id=%s", f.Name(), *f.Data.SystemID)
}

Subscribe

Client provides built-in function to handle feed updates.

err := c.Subscribe(gbfs.ClientSubscribeOptions{
    // Languages: []string{"en"},
    // FeedNames: []string{gbfs.FeedNameStationInformation, gbfs.FeedNameFreeBikeStatus},
    Handler: func(c *gbfs.Client, f gbfs.Feed, err error) {
        if err != nil {
            log.Println(err)
            return
        }
        j, _ := json.Marshal(f)
        log.Printf("feed=%s data=%s", f.Name(), j)
    },
})
if err != nil {
    log.Println(err)
}

Subscription options Languages and FeedNames restrict subscription only to selected languages and feeds.

Server

import "github.com/petoc/gbfs/v2"

s, err := gbfs.NewServer(gbfs.ServerOptions{
    SystemID:     "system_id",
    RootDir:      "public",
    BaseURL:      "http://127.0.0.1:8080",
    BasePath:     "v2/system_id",
    Version:      gbfs.V21,
    DefaultTTL:   60,
    FeedHandlers: []*gbfs.FeedHandler{
        // see example for how to add feed handlers
    },
    UpdateHandler: func(s *gbfs.Server, feed gbfs.Feed, path string, err error) {
        if err != nil {
            log.Println(err)
            return
        }
        log.Printf("system=%s ttl=%d version=%s updated=%s", s.Options.SystemID, feed.GetTTL(), feed.GetVersion(), path)
    },
})
if err != nil {
    log.Fatal(err)
}
log.Fatal(s.Start())

Main autodiscovery feed gbfs.json will be constructed from all available feeds in FeedHandlers. After that, all FeedHandlers will be regularly executed after configured TTL. If TTL is not set for individual feeds, it will be inherited from FeedHandler. If TTL is not set even for FeedHandler, DefaultTTL from ServerOptions will be used for feed.

Serving feeds

Feeds can be served as static files with standard webservers (Nginx, Apache, ...) or with simple built-in static file server.

fs, err := gbfs.NewFileServer("127.0.0.1:8080", "public")
if err != nil {
    log.Fatal(err)
}
log.Fatal(fs.ListenAndServe())

License

Licensed under MIT license.