Orbit

Orbit is a tool to store and share URI based on your current location

Development

brew install mongodb
git clone git://github.com/zix2c/orbit.git
npm install vows -g
cd orbit
npm install

Involved projects

• mongoose
• express
• jade
• MongoDB

Heroku

Install the toolbelt utilities

brew install git
sudo gem install foreman
sudo gem install heroku

Create the instance

$ heroku login
Enter your Heroku credentials.
Email: adam@example.com
Password:
heroku create --stack cedar
Creating stark-fog-398... done, stack is cedar
http://stark-fog-398.herokuapp.com/ | git@heroku.com:stark-fog-398.git
Git remote heroku added

Create database

heroku addons:add mongolab:starter

Deploy and run

git push heroku master
heroku ps:scale web=1

Check the process

heroku ps
heroku logs

Layout

The database layout is very simple. (For now) we only need one collection. Examplary save()

db.bookmarks.save(
	{
		url: "http://hackathon.advance-conference.com/",
		title: "Advance Hackathon",
		label: "/",
		location : { lon : 6.98668, lat: 50.94926 },
		created: "2012-04-29T14:15Z",
		expires: "2012-04-29T16:15Z"
	}
);

• url the url we want to share
• title title of the homepage
• label for categorizing and searching/sorting
• location where do we share the bookmark
• created ISO 8601 encoded timestamp when bookmark was created
• expires ISO 8601 encoded timestamp when the entry is purged from database

Indices

Speedup searching for a label

db.orbit.ensureIndex({ label : 1 })

MongoDB supports spatial Indexing

Caveats

1. MongoDB 1.8+ supports spherical geometries.
2. MongoDB assumes that you are using decimal degrees in (longitude, latitude) order. This is the same order used for the GeoJSON spec.
3. All distances use radians. 4.MongoDB doesn't handle wrapping at the poles or at the transition from -180° to +180° longitude but raises an error. 5.Earth-like bounds are [-180, 180), valid values for latitude are between -90° and 90°.

Creating the spatial index

db.orbit.ensureIndex({ location : "2d" })
var earthRadius = 6378 // km
var range = 3000 // km

Searching for a bookmark near a location

distances = db.runCommand({ geoNear : "points", near : [0, 0], spherical : true, maxDistance : range / earthRadius /* to radians */ }).results

Scaffolding

Start mongodb daemon

$ mongod run --config /usr/local/Cellar/mongodb/2.0.4-x86_64/mongod.conf

Start mongoDB shell and store an exampe bookmark

$ mongo
> db.bookmarks.save(
	{
		url: "http://hackathon.advance-conference.com/",
		title: "Advance Hackathon",
		label: "/",
		location : { lon : 6.98668, lat: 50.94926 },
		created: "2012-04-29T14:15Z",
		expires: "2012-04-29T16:15Z"
	}
);

Mongoose

Search for label only

ItemModel.find( {label: 'global'} , function(err, docs){ /* code */ });

Search for a location

ItemModel.find({location : { $near : [23, 56], $maxDistance: 30 }} , function(err, docs){ /* code */ });

Seach for a label and location

ItemModel.find({label: 'global', location : { $near : [23, 56], $maxDistance: 30 }} , function(err, docs){ /* code */ });

API

Get bookmarklet and store the location

GET http://orbit2.herokuapp.com/?bookmarklet=true&lat=x&lon=y&title=...&url=...
Accept: text/html
=> html, 200

Show index (user types orbit domain in address bar)

GET http://orbit2.herokuapp.com/
Accept: text/html
=> html, 200

Get bookmarks at given lat,lon in circle of radius r

GET http://orbit2.herokuapp.com/?lat=x&lon=y&radius=r
Accept: application/json
=> json, 200