Remove link from minimal

- whilst this seemed like a good idea at the time, it presents some issues, notably that the chart has nothing that indicates it is a link and can be clicked on
- better to remove the link entirely and provide better guidance on how minimal mode should be used i.e. manage linking to or showing more data at an application level, rather than the component level

app/assets/stylesheets/govuk_publishing_components/components/_chart.scss

@@ -40,28 +40,3 @@
     text-align: center;
   }
 }
-
-.gem-c-chart__minimal-link {
-  position: absolute;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 100%;
-
-  &:focus {
-    background: transparent; // overrides govuk-link background, which obscures the graph
-
-    &::after {
-      content: "";
-      position: absolute;
-      top: 0;
-      left: 0;
-      width: 100%;
-      height: 100%;
-      border-top: solid 1px $govuk-focus-colour;
-      border-left: solid 3px $govuk-focus-colour;
-      border-right: solid 3px $govuk-focus-colour;
-      box-sizing: border-box;
-    }
-  }
-}

app/views/govuk_publishing_components/components/_chart.html.erb

@@ -13,7 +13,6 @@
   keys ||= []
   chart_overview ||= nil
   minimal ||= false
-  minimal_link ||= nil
   hide_legend ||= minimal
   link ||= false
   height ||= 400
@@ -42,9 +41,6 @@
   enableInteractivity = false if minimal
   textPosition = nil
   textPosition = 'none' if minimal
-  if minimal && !minimal_link
-    raise ArgumentError, "Minimal version must include a link"
-  end
 
   chart_library_options = {
     chartArea: { width: '80%', height: '60%' },
@@ -171,10 +167,5 @@
         </p>
       <% end %>
     <% end %>
-    <% if minimal %>
-      <%= link_to(minimal_link, class: "govuk-link gem-c-chart__minimal-link") do %>
-        <span class="govuk-visually-hidden"><%= chart_heading %></span>
-      <% end %>
-    <% end %>
   <% end %>
 <% end %>

app/views/govuk_publishing_components/components/docs/chart.yml

@@ -243,10 +243,11 @@ examples:
             - 80
   minimal_version:
     description: |
-      The minimal version presents a simplified version of the chart and should only be used where the user is then directed to a more detailed view of the data. Specifically, minimal mode:
+      The minimal version presents a simplified version of the chart. This should only be used where there is not enough space to display a full chart, and the user is then given an option to see more information about the chart, for example by including a link next to the chart component. This must be part of the page, as this is not provided by the component itself.
 
-      - turns the chart into a link that should point to a page with a full version of the chart with all data
-      - hides the chart heading, but uses the text as the text for the link
+      Specifically, minimal mode:
+
+      - hides the chart heading
       - removes the legend and X and Y axis values
       - removes the data table and link to the data (if supplied) beneath the chart
       - removes the part of the visually hidden accessibility message that links to the table
@@ -257,7 +258,6 @@ examples:
       h_axis_title: Day
       v_axis_title: Views
       minimal: true
-      minimal_link: "https://www.gov.uk"
       chart_overview: This is a graph of views per day
       keys:
         - 1st
@@ -296,7 +296,6 @@ examples:
       h_axis_title: Day
       v_axis_title: Views
       minimal: true
-      minimal_link: "https://www.gov.uk"
       chart_overview: This is a graph of views per day
       height: 200
       keys:

spec/components/chart_spec.rb

@@ -109,24 +109,15 @@ def component_name
   it "renders a minimal version" do
     data[:minimal] = true
     data[:link] = "https://should.not.be.shown"
-    data[:minimal_link] = "https://www.gov.uk"
     data[:chart_overview] = "This is a chart showing a rise in sea levels in the last ten years"
     render_component(data)
 
     assert_select ".gem-c-chart.gem-c-chart--minimal"
     assert_select ".gem-c-chart__chart[aria-hidden='true']"
     assert_select '.gem-c-chart .govuk-link[href="https://should.not.be.shown"]', false
-    assert_select '.gem-c-chart .gem-c-chart__minimal-link[href="https://www.gov.uk"]'
     assert_select ".gem-c-chart__chart .govuk-visually-hidden", false
   end
 
-  it "does not render a minimal version if a link is not supplied" do
-    data[:minimal] = true
-    expect {
-      render_component(data)
-    }.to raise_error("Minimal version must include a link")
-  end
-
   it "only calls an external script once" do
     render_component(data)
     data[:classes] = "" # need to 'reset' this otherwise it carries from the first component and breaks shared_helper