Highcharts - Rails array includes empty date entries - ruby-on-rails

Question

I'm working on a Rails 3.1.1 app with a dashboard of various line graphs using Highcharts. I implemented the sample code in Railcast 223 (highcharts) -- and everything works as expected. But on days when no entries exists, the array plots a 0 value -- but I'm only looking to line graph actual records.
Its not an issue with the Railscast because they sample has multiple Order entries each day. It appears to be the same issue posted by another user (Thomas)...though his code didn't work in my situation.
Index view:
$(function () {
new Highcharts.Chart({
chart: { renderTo: 'orders_chart' },
title: { text: 'Orders by Day' },
xAxis: { type: 'datetime' },
yAxis: {
title: { text: 'Dollars' }
},
tooltip: {
formatter: function () {
return Highcharts.dateFormat("%B %e %Y", this.x) + ': ' +
'$' + Highcharts.numberFormat(this.y, 2);
}
},
series: [{
pointInterval: <%= 1.day * 1000 %>,
pointStart: <%= 3.weeks.ago.at_midnight.to_i * 1000 %>,
data: <%= (3.weeks.ago.to_date..Date.today).map { |date| Order.total_on(date).to_f}.inspect %>
}]
});
});
class Order < ActiveRecord::Base
def self.total_on(date)
where("date(purchased_at) = ?",date).sum(:total_price)
end
end
Any input would be greatly appreciate -- new to rails and have already found the 100 ways the don't work! Thanks!

Answer 1

If you want nothing to be graphed but the date to still show up, then change any zeroes to a javascript null. If you want to not graph those days, then you should reject them from the array before output.
So:
(3.weeks.ago.to_date..Date.today).map{|date| total=Order.total_on(date).to_f; total.zero? ? "null" : total }.inspect
Or:
(3.weeks.ago.to_date..Date.today).map{|date| Order.total_on(date).to_f}.reject(&:zero?).inspect