event-search

Search Facebook events by location (as a service)

A Express.js-based webservice to get public Facebook events by location and distances, as well as search terms. It can be used as a starting point for an location-based app for example.

Motivation

As Facebook has discontinued the FQL query API for all apps created after 2014-04-30, it has gotten much more complicated to search for public Facebook events by location and distances. This is the reason why this project was created.

Basics

The implementation of facebook-events-by-location-core, which is used for providing the Facebook events search functionality, 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={query}&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
• 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.

Installation

As NPM package

The application can be installed via

npm install facebook-events-by-location

in the root directory, and either started with

npm start or node index.js.

Git

To clone the repository, use

git clone https://github.com/tobilg/facebook-events-by-location.git

and run cd facebook-events-by-location && npm i && npm start to install the dependencies and run the web service.

As Docker microservice

You can build the Docker image via docker build -t <yourTag> . locally if you like. Also, there's an official image (called tobilg/facebook-event-search) in the Docker hub.

The service can be launched via Docker like this:

docker run -d --name fb-event-search -p 3000:3000 tobilg/facebook-event-search

This would expose the app on port 3000 on the Docker host. If you want to specify another port for the app, you can use -e "PORT0=10000" together with --net="host" (be aware of the security implications of host networking).

Environment variables

You can use the following environment variables to influence the application:

• FEBL_ACCESS_TOKEN: Used to define a general App Access Token to be used for the requests to the Graph API. This is overridden if the request specifies an accessToken parameter. If it's not specified, every request to /events needs to contain an accessToken parameter.
• FEBL_CORS_WHITELIST: You can pass a comma-separated domain whitelist to enable CORS headers (e.g. http://www.test.com,http://www.test.org). If you don't specify this variable, CORS will be enabled on all origins.
• HOST: The IP address the Express application should bind to. Default is 0.0.0.0 (all available IP addresses).
• PORT0: The port on which the application should run. Default is 3000.

API

The basic endpoint is GET /events, but there's also a GET /health endpoint to enable health checks.

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

Non-mandatory parameters

• query: The term(s) on which you want to narrow down your location search (this only filters the places, not the events itself!).
• accessToken: The App Access Token to be used for the requests to the Graph API.
• distance: The distance in meters (it makes sense to use smaller distances, like max. 2500). Default is 100.
• 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.
• version: The version of the Graph API to use. Default is v2.7.
• since: The start of the range to filter results. Format is Unix timestamp or strtotime data value, as accepted by FB Graph API.
• until: The end of the range to filter results.

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:3000/events?lat=40.710803&lng=-73.964040&distance=100&sort=venue&accessToken=YOUR_APP_ACCESS_TOKEN (make sure you replace YOUR_APP_ACCESS_TOKEN with a real access token!)

Sample output (shortened)

{
    "events": [{
        "id": "163958810691757",
        "name": "3Bridge Records presents inTRANSIT w/ David Kiss, Deep Woods, Eric Shans",
        "coverPicture": "https://scontent.xx.fbcdn.net/t31.0-8/s720x720/13679859_10153862492796325_8533542782240254857_o.jpg",
        "profilePicture": "https://scontent.xx.fbcdn.net/v/t1.0-0/c133.0.200.200/p200x200/13872980_10153862492796325_8533542782240254857_n.jpg?oh=a46813bbf28ad7b8bffb88acd82c7c71&oe=581EF037",
        "description": "Saturday, August 20th.\n\nJoin the 3Bridge Records team for another night of sound and shenanigans - as we send Deep Woods & David Kiss out to Burning Man & belatedly celebrate Slav Ka's debut release on the label - \"Endless\" - out May 14th, featuring a remix by Mr. Shans.\n\nDavid Kiss (House of Yes)\nhttps://soundcloud.com/davidkiss\n\nDeep Woods (3Bridge Records)\nhttps://soundcloud.com/deep-woods\n\nEric Shans (3Bridge Records)\nhttps://soundcloud.com/eric-shans\n\nSlav Ka (3Bridge Records)\nhttps://soundcloud.com/slinkyslava\n\nFree before 12, $10 after (+ 1 comp well drink). $5 presale available on RA.\n\nhttps://www.residentadvisor.net/event.aspx?863815\n\nStay dope, Brooklyn.",
        "distance": "203",
        "startTime": "2016-08-20T22:00:00-0400",
        "timeFromNow": 481946,
        "stats": {
            "attending": 44,
            "declined": 3,
            "maybe": 88,
            "noreply": 1250
        },
        "venue": {
            "id": "585713341444399",
            "name": "TBA Brooklyn",
            "coverPicture": "https://scontent.xx.fbcdn.net/v/t1.0-9/s720x720/13932666_1397749103574148_4391608711361541993_n.png?oh=2d82be3a458d1ce9ac8fab47cdbc6e26&oe=585E6545",
            "profilePicture": "https://scontent.xx.fbcdn.net/v/t1.0-1/p200x200/12049351_1300865083262551_8221231831784471629_n.jpg?oh=a30798841ad60dfe5cfabaa4e803c3ad&oe=5854DFB9",
            "location": {
                "city": "Brooklyn",
                "country": "United States",
                "latitude": 40.711217064583,
                "longitude": -73.966384349735,
                "state": "NY",
                "street": "395 Wythe Ave",
                "zip": "11249"
            }
        }
    },
    ... 
    ],
    "metadata": {
        "venues": 1,
        "venuesWithEvents": 1,
        "events": 4
    }
}