Converting data

Representing a Feed

The cosm-rb library makes it easy to convert Ruby objects into Cosm ones.

feed = Cosm::Feed.new # initialize a new Feed object
feed.title = "My Cosm Feed"
feed.datastreams = [Cosm::Datastream.new(:id => 'test')] # Let's give it one datastream with id 'test'

Let's see what it looks like:

feed.to_json
=> {"title":"Test feed","version":"1.0.0","datastreams":[{"id":"test"}]}

You can also represent objects in Cosm xml and csv

Parsing a feed

The cosm-rb library makes it easy to convert Cosm data into a Ruby object

Parsing a Datastream using json

json = <<-EOJSON
  {   
      "max_value": "658.0",
      "current_value": "14",
      "datapoints": [{
          "value": "1",
          "at": "2011-03-02T15:59:56.895922Z"
      },  
      {   
          "value": "1",
          "at": "2011-03-02T16:00:07.188648Z"
      },  
      {   
          "value": "2",
          "at": "2011-03-02T16:00:18.416500Z"
      }], 
      "min_value": "0.0",
      "id": "0",
      "tags": ["humidity", "Temperature", "freakin lasers"],
      "version": "1.0.0",
      "unit": {
          "label": "percentage",
          "symbol": "%",
          "type": "derived SI" 
      },  
      "at": "2011-02-16T16:21:01.834174Z"
  }
EOJSON

datastream = Cosm::Datastream.new(json)
datastream.to_xml # =>
# <?xml version="1.0" encoding="UTF-8"?>
# <eeml xmlns="http://www.eeml.org/xsd/0.5.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="0.5.1" xsi:schemaLocation="http://www.eeml.org/xsd/0.5.1 http://www.eeml.org/xsd/0.5.1/0.5.1.xsd">
#   <environment creator="" updated="2011-02-16T16:21:01.834174Z" id="">
#     <data id="0">
#       <tag>freakin lasers</tag>
#       <tag>humidity</tag>
#       <tag>Temperature</tag>
#       <current_value at="2011-02-16T16:21:01.834174Z">14</current_value>
#       <max_value>658.0</max_value>
#       <min_value>0.0</min_value>
#       <unit type="derived SI" symbol="%">percentage</unit>
#       <datapoints>
#         <value at="2011-03-02T15:59:56.895922Z">1</value>
#         <value at="2011-03-02T16:00:07.188648Z">1</value>
#         <value at="2011-03-02T16:00:18.416500Z">2</value>
#       </datapoints>
#     </data>
#   </environment>
# </eeml>