itolosa/ruby-fb-events-by-location

Ruby Search Facebook events by location

NOTE: This is a Ruby version based on Tobilg Facebook Event By Location. Some concepts and parts of that code could have been used in this project.

As Facebook has discontinued the FQL query API for all apps created after 2014-04-30, it has gotten much more complicated to get public Facebook events by passing a location.

This implementation uses regular Facebook Graph API calls in a three-step approach to get the events:

1. Search for places in the radius of the passed coordinate and distance (/search?type=place&q=*&center={coordinate}&distance={distance})
2. Use the places to query for their events in parallel (/?ids={id1},{id2},{id3},...)
3. Unify, filter and sort the results from the parallel calls and return them to the client

###Known limitations

• The Graph API has some "instabilities" with search results. It's possible that the amount of results returned can vary between calls within seconds
• Undocumented usage of the q parameter (q=* produced more results than q= or just omitting the q parameter)
• The /search endpoint "magically" limits the number of results, independent from the distance used (larger distance doesn't guarantee more results)
• Rate limiting will apply, but I experienced no call blocks within a reasonable amount of service requests. Be aware that the way this application works, there are potentially hundreds of (counted) Graph API calls per request to /events.

Git

To clone the repository, use

git clone https://github.com/itolosa/ruby-fb-events-by-location.git

and run cd ruby-fb-events-by-location && bundle install && rackup to install the dependencies and run the web service.

##API The basic endpoint is /events, the port of the application can be set via environment variable.

###Query paramenters Mandatory parameters are the following:

• lat: The latitude of the position/coordinate the events shall be returned for
• lng: The longitude of the position/coordinate the events shall be returned for
• dist: The distance in meters (it makes sense to use smaller distances, like max. 2500)
• access_token: The App Access Token to be used for the requests to the Graph API

Non-mandatory parameters

• sort: The results can be sorted by time, distance, venue or popularity. If omitted, the events will be returned in the order they were received from the Graph API

###Query results The response will be application/json and contain an events property containing the array of event objects, as well as a metadata property with some stats. See below for an example.

###Sample call

http://localhost:9292/api/events?access_token=<your-access-token>&lat=-33.4475741&lng=-70.6372606&q_sort=&dist=10000 (make sure you replace <your-access-token> with a real access token!)

###Sample output (shortened)

{
    "events": [
        {
            "venueId": "460616340718401",
            "venueName": "Baby's All Right",
            "venueCoverPicture": "https://scontent.xx.fbcdn.net/hphotos-xfa1/t31.0-8/s720x720/12265652_847575375355827_6601509754180711535_o.jpg",
            "venueProfilePicture": "https://scontent.xx.fbcdn.net/hprofile-xft1/v/t1.0-1/p200x200/1480734_642185745894792_5820988503650852577_n.png?oh=fc70de542d587b32e7a8a9183ddb0560&oe=56E4082D",
            "venueLocation": {
                "city": "Brooklyn",
                "country": "United States",
                "latitude": 40.70998,
                "longitude": -73.9634705,
                "state": "NY",
                "street": "146 Broadway",
                "zip": "11211"
            },
            "eventId": "1671296009750385",
            "eventName": "Baby's All Basel | Dec 2 - 6 | Baby's All Right Miami Pop Up",
            "eventCoverPicture": "https://scontent.xx.fbcdn.net/hphotos-xpa1/v/t1.0-9/s720x720/12249784_1002625069800744_6143497234204516409_n.png?oh=6e5b3eaa2a369d819d160560173cdbea&oe=56E61E88",
            "eventProfilePicture": "https://scontent.xx.fbcdn.net/hphotos-xpa1/v/t1.0-0/c120.0.200.200/p200x200/12249784_1002625069800744_6143497234204516409_n.png?oh=9bc7c7dcd65934ab74010a890d9ac070&oe=56F5E8D3",
            "eventDescription": "POPLIFE Presents:\n\nBABY'S ALL BASEL\n\nBrooklyn's Baby's All Right is touching down in Miami for a week full of live music & parties!\n\nGet involved in all the fun:\nhttp://epop.life/BabysMiami\n\n21+ \n\n#BabysMiami",
            "eventStarttime": "2015-12-02T17:00:00-0800",
            "eventDistance": "103",
            "eventTimeFromNow": 884065,
            "eventStats": {
                "attendingCount": 143,
                "declinedCount": 0,
                "maybeCount": 96,
                "noreplyCount": 1117
            }
        },
        ...
    ],
    "metadata": {
        "venues": 350,
        "venuesWithEvents": 7,
        "events": 23
    }
}