1 files changed, 14 insertions, 0 deletions
diff --git a/app/models/nutrient_measurement.rb b/app/models/nutrient_measurement.rb
index f1d6d5b..1139af7 100644
--- a/app/models/nutrient_measurement.rb
+++ b/app/models/nutrient_measurement.rb
@@ -1,4 +1,18 @@
 class NutrientMeasurement < ApplicationRecord
+  NUTRIENT_FIELDS = %i[
+    nno3 p k ca mg s na cl si fe zn b mn cu mo nnh4
+  ].freeze
+
   validates :measured_on, presence: true
   validates :measured_on, uniqueness: true
+
+  def self.data_series_for(*nutrients)
+    nutrients.map do |formula|
+      { name: formula, data: self.order(:measured_on).pluck(:measured_on, formula) }
+    end
+  end
+
+  def self.nutrient_fields
+    NUTRIENT_FIELDS
+  end
 end