gistfile1.rb

# I have a hash `dates` that I get from "DateTime.now - 7, DateTime.now" in my database.
# I need to turn it into a full week where if the date doesn't exist put a 0 in as the value of the date key.

dates = {"2014-01-15"=>1, "2014-01-17"=>1, "2014-01-18"=>1, "2014-01-19"=>17}

week_hash = {
  "2014-01-13"=>0, 
  "2014-01-14"=>0,
  "2014-01-15"=>1, 
  "2014-01-16"=>0,
  "2014-01-17"=>1, 
  "2014-01-18"=>1, 
  "2014-01-19"=>17
  }

Here is what I came up with

amount = @profile.impressions.where("created_at >= ? and created_at <= ?", DateTime.now - 7, DateTime.now)
dates = {}
(1.week.ago.to_date..Date.today).each {|x| dates[x.strftime("%Y-%m-%d")] = 0 }
dates.merge!(amount.count( :group => "message", :order => "message ASC"))

I'm writing it to an api so I can show how many views a profile had in the past week, so I want it in a full week json bag like so:

"views": [
    {
      "date": "2014-01-12",
      "count": 0
    },
    {
      "date": "2014-01-13",
      "count": 0
    },
    {
      "date": "2014-01-14",
      "count": 0
    },
    {
      "date": "2014-01-15",
      "count": 1
    },
    {
      "date": "2014-01-16",
      "count": 0
    },
    {
      "date": "2014-01-17",
      "count": 1
    },
    {
      "date": "2014-01-18",
      "count": 1
    },
    {
      "date": "2014-01-19",
      "count": 17
    }
  ]

I believe this will work for me.

I do get these warnings though

DEPRECATION WARNING: Relation#calculate with finder options is deprecated. Please build a scope and then call calculate on it instead. (called from show at /Users/johnlong/Projects/yak/app/controllers/api/v1/user_profile_controller.rb:12)
DEPRECATION WARNING: The :distinct option for `Relation#count` is deprecated. Please use `Relation#distinct` instead. (eg. `relation.distinct.count`). (called from show at /Users/johnlong/Projects/yak/app/controllers/api/v1/user_profile_controller.rb:12)

It seems this is where it's coming from

amount.count( :group => "message", :order => "message ASC")

Looks good! Yeah, needing to serialize that data into a JSON object is definitely a different story. One quick thing: you're generating two equivalent dates two different ways at two different times. If your database connection stalls for a few seconds, you could accidentally end up with mismatched results. Just generate your date once, like

week_ago = Date.today - 7

so you don't end up with time mismatches. The deprecation warnings are because that's the old Rails 3.x syntax for .count. Look into the .group and .order methods instead.

Thanks dood! @piersadrian