Scaffold for Statistics block on Landing pages

app/assets/javascripts/dependencies.js

@@ -8,3 +8,5 @@
 //= require govuk_publishing_components/components/step-by-step-nav
 //= require govuk_publishing_components/components/table
 //= require govuk_publishing_components/components/tabs
+
+//= require govuk_publishing_components/components/chart

app/models/block/statistics.rb

@@ -0,0 +1,69 @@
+require "csv"
+
+module Block
+  class Statistics < Block::Base
+    STATISTICS_DATA_PATH = "lib/data/landing_page_content_items/statistics".freeze
+
+    def title
+      data["title"]
+    end
+
+    def x_axis_label
+      data["x_axis_label"]
+    end
+
+    def y_axis_label
+      data["y_axis_label"]
+    end
+
+    def hide_legend
+      data["hide_legend"]
+    end
+
+    def x_axis_keys
+      @x_axis_keys ||= csv_rows.map { |row| row[row.keys.first] }.uniq
+    end
+
+    def rows
+      row_lines.map do |key, value|
+        {
+          label: key.to_s,
+          values: value[:values],
+        }
+      end
+    end
+
+    def data_source_link
+      data["data_source_link"]
+    end
+
+  private
+
+    def row_lines
+      csv_rows.each_with_object({}) do |row, lines|
+        label = row.keys.first
+        variable_name = row.values.second
+        value = row.values.last
+        if lines.key?(variable_name)
+          lines[variable_name][:values] << value.to_i
+        else
+          lines[variable_name] = {
+            label:,
+            values: [
+              value.to_i,
+            ],
+          }
+        end
+      end
+    end
+
+    def csv_rows
+      rows = CSV.read(csv_file_path, headers: true).map(&:to_h)
+      rows.each(&:deep_symbolize_keys!)
+    end
+
+    def csv_file_path
+      @csv_file_path ||= Rails.root.join("#{STATISTICS_DATA_PATH}/#{data['csv_file']}")
+    end
+  end
+end

app/views/landing_page/blocks/_statistics.html.erb

@@ -0,0 +1,13 @@
+<%
+  add_gem_component_stylesheet("chart")
+%>
+
+<%= render "govuk_publishing_components/components/chart", {
+  chart_heading: block.title,
+  h_axis_title: block.x_axis_label,
+  v_axis_title: block.y_axis_label,
+  hide_legend: block.hide_legend,
+  keys: block.x_axis_keys,
+  rows: block.rows,
+} %>
+<%= link_to block.data["data_source_link_text"], block.data_source_link %>

lib/data/landing_page_content_items/landing_page.yaml

@@ -167,6 +167,21 @@ blocks:
           - type: govspeak
             inverse: true
             content: <h2><a href="http://gov.uk">Title 2 govspeak title goes here</a></h2>
+- type: statistics
+  title: "Chart to visually represent some data"
+  x_axis_label: "X Axis"
+  y_axis_label: "Y Axis"
+  hide_legend: true
+  csv_file: "data_one.csv"
+  data_source_link_text: "Data source"
+  data_source_link: https://www.ons.gov.uk/economy/grossdomesticproductgdp/timeseries/ihyq/qna
+- type: statistics
+  title: "Chart to visually represent some more data"
+  x_axis_label: "X Axis"
+  y_axis_label: "Y Axis"
+  csv_file: "data_two.csv"
+  data_source_link_text: "Data source"
+  data_source_link: https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23
 - type: share_links
   links:
     - href: "/twitter-share-link"

lib/data/landing_page_content_items/statistics/data_one.csv

@@ -0,0 +1,7 @@
+Date,variable,value
+2024-01-01,variable_name,10
+2024-02-01,variable_name,11
+2024-03-01,variable_name,12
+2024-04-01,variable_name,13
+2024-05-01,variable_name,14
+2024-06-01,variable_name,15

lib/data/landing_page_content_items/statistics/data_two.csv

@@ -0,0 +1,7 @@
+Date,variable,value
+2023-01-01,variable_name,20
+2023-02-01,variable_name,21
+2023-03-01,variable_name,22
+2023-01-01,variable_name_two,23
+2023-02-01,variable_name_two,24
+2023-03-01,variable_name_two,25

spec/fixtures/landing_page.yaml

@@ -109,7 +109,7 @@ blocks:
     card_content:
       blocks:
         - type: govspeak
-          inverse: true 
+          inverse: true
           content: <h2><a href="http://gov.uk">Title 2 govspeak title goes here</a></h2>
   - type: card
     image:
@@ -146,3 +146,10 @@ blocks:
           - type: govspeak
             inverse: true
             content: <h2><a href="http://gov.uk">Title 2 govspeak title goes here</a></h2>
+- type: statistics
+  title: "Chart to visually represent data"
+  x_axis_label: "X Axis"
+  y_axis_label: "Y Axis"
+  csv_file: "data_one.csv"
+  data_source_link_text: "Data source"
+  data_source_link: https://www.example.com

spec/fixtures/landing_page_statistics_data/data_one.csv

@@ -0,0 +1,7 @@
+Date,variable,value
+2024-01-01,variable_name,10
+2024-02-01,variable_name,11
+2024-03-01,variable_name,12
+2024-04-01,variable_name,13
+2024-05-01,variable_name,14
+2024-06-01,variable_name,15

spec/fixtures/landing_page_statistics_data/data_two.csv

@@ -0,0 +1,7 @@
+Date,variable,value
+2024-01-01,variable_name,10
+2024-02-01,variable_name,11
+2024-03-01,variable_name,12
+2024-01-01,variable_name_two,13
+2024-02-01,variable_name_two,14
+2024-03-01,variable_name_two,15

spec/models/block/statistics_spec.rb

@@ -0,0 +1,107 @@
+RSpec.describe Block::Statistics do
+  let(:blocks_hash) do
+    {
+      "type" => "statistics",
+      "title" => "Chart to visually represent data",
+      "x_axis_label" => "X Axis",
+      "y_axis_label" => "Y Axis",
+      "csv_file" => "data_one.csv",
+      "data_source_link_text" => "Data source",
+      "data_source_link" => "https://www.example.com",
+    }
+  end
+
+  before do
+    Block::Statistics.send(:remove_const, "STATISTICS_DATA_PATH")
+    Block::Statistics.const_set("STATISTICS_DATA_PATH", "spec/fixtures/landing_page_statistics_data")
+  end
+
+  after do
+    Block::Statistics.send(:remove_const, "STATISTICS_DATA_PATH")
+    Block::Statistics.const_set("STATISTICS_DATA_PATH", "lib/data/landing_page_content_items/statistics")
+  end
+
+  describe "statistics content" do
+    describe "#title" do
+      it "gets statistics title" do
+        expect(described_class.new(blocks_hash).title).to eq("Chart to visually represent data")
+      end
+    end
+
+    describe "#x_axis_label" do
+      it "gets the label for the x-axix" do
+        expect(described_class.new(blocks_hash).x_axis_label).to eq("X Axis")
+      end
+    end
+
+    describe "#y_axis_label" do
+      it "gets the label for the y-axis" do
+        expect(described_class.new(blocks_hash).y_axis_label).to eq("Y Axis")
+      end
+    end
+  end
+
+  describe "chart data" do
+    describe "#data_source_link" do
+      it "returns the link to the external data source" do
+        expect(described_class.new(blocks_hash).data_source_link).to eq("https://www.example.com")
+      end
+    end
+
+    describe "#x_axis_keys" do
+      it "gets all of the x-axis data points" do
+        expected_keys = %w[
+          2024-01-01
+          2024-02-01
+          2024-03-01
+          2024-04-01
+          2024-05-01
+          2024-06-01
+        ]
+
+        expect(described_class.new(blocks_hash).x_axis_keys).to eq(expected_keys)
+      end
+
+      it "gets all of the unique x-axis data points" do
+        expected_keys = %w[
+          2024-01-01
+          2024-02-01
+          2024-03-01
+        ]
+        blocks_hash["csv_file"] = "data_two.csv"
+
+        expect(described_class.new(blocks_hash).x_axis_keys).to eq(expected_keys)
+      end
+    end
+
+    describe "#rows" do
+      it "gets the rows for one line of data" do
+        expected_rows = [
+          {
+            label: "variable_name",
+            values: [10, 11, 12, 13, 14, 15],
+          },
+        ]
+
+        expect(described_class.new(blocks_hash).rows).to eq(expected_rows)
+      end
+
+      it "gets the rows for multiple lines of data" do
+        expected_rows = [
+          {
+            label: "variable_name",
+            values: [10, 11, 12],
+          },
+          {
+            label: "variable_name_two",
+            values: [13, 14, 15],
+          },
+        ]
+
+        blocks_hash["csv_file"] = "data_two.csv"
+
+        expect(described_class.new(blocks_hash).rows).to eq(expected_rows)
+      end
+    end
+  end
+end