feat: add archive banner based on semester date range

Agent-Logs-Url: https://github.com/berkeley-cdss/berkeley-class-site/sessions/b541e009-643e-4e51-a543-e291bb28f017

Co-authored-by: cycomachead <1505907+cycomachead@users.noreply.github.com>

Author: Copilot

_config.yml

@@ -36,6 +36,8 @@ gradescope_course_id: 123456 # you can find this in the Gradescope URL after /co
 bcourses_course_id: 123456 # Same as above, but for bCourses. Leave blank if not in use...
 ed_course_id: 123456 # Again, same as above.
 sememster: spYY | suYY | faYY # set for the current seemester
+semester_start_date: '2025-01-21' # Required for the archive banner logic (YYYY-MM-DD)
+semester_end_date: '2025-05-09' # Required for the archive banner logic (YYYY-MM-DD)
 # TODO(setup): Set this to the file path of your course logo image, or leave it blank to display your course name.
 # To edit the size and positioning of the logo/course name, see _sass/custom/course_overrides.scss
 logo: /assets/images/berkeley_walking_bear.png
@@ -45,6 +47,7 @@ course_department: dsus
 # This should be the page of all class archives
 # Typically just / for DS courses (with a visible index page), or /archives if you're hosting your own, or a link to the inst.eecs page
 # If you have no archive page, comment this line out or leave blank.
+# We recommend listing archived offerings as "Archive" or "Not Updated" in course listings.
 class_archive_path: /
 
 # TODO(setup): Remove this line if your favicon is named favicon.ico and is in the root directory,

_includes/header_custom.html

@@ -0,0 +1,46 @@
+<div id="archive-banner" class="archive-banner" role="status">
+  This site is archived. Please check:
+  <a id="archive-banner-link" class="archive-banner-link" href="#"></a>
+</div>
+
+<script>
+  (() => {
+    const semesterStart = {{ site.semester_start_date | jsonify }};
+    const semesterEnd = {{ site.semester_end_date | jsonify }};
+    const archivePath = {{ site.class_archive_path | jsonify }};
+
+    if (!semesterStart || !semesterEnd || !archivePath) {
+      return;
+    }
+
+    const parseDate = (value) => {
+      const parsed = new Date(value);
+      return Number.isNaN(parsed.getTime()) ? null : parsed;
+    };
+
+    const startDate = parseDate(semesterStart);
+    const endDate = parseDate(semesterEnd);
+    if (!startDate || !endDate) {
+      return;
+    }
+
+    endDate.setHours(23, 59, 59, 999);
+    const currentDate = new Date();
+    const isOutsideSemester = currentDate < startDate || currentDate > endDate;
+    if (!isOutsideSemester) {
+      return;
+    }
+
+    const archiveUrl = new URL(archivePath, window.location.origin).toString();
+    const banner = document.getElementById('archive-banner');
+    const archiveLink = document.getElementById('archive-banner-link');
+    if (!banner || !archiveLink) {
+      return;
+    }
+
+    archiveLink.href = archiveUrl;
+    archiveLink.textContent = archiveUrl;
+    banner.style.display = 'block';
+    document.body.classList.add('archive-banner-visible');
+  })();
+</script>

_plugins/config_validator.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'date'
+
 # A UC Berkeley-specific validator for Jekyll sites
 # This class validates the following options:
 # 1) Ensures required attributes are present in the config file.
@@ -44,7 +46,9 @@ class ConfigValidator
       url: :validate_clean_url,
       baseurl: :validate_semester_format,
       course_department: :inclusion_validator,
-      color_scheme: :inclusion_validator
+      color_scheme: :inclusion_validator,
+      semester_start_date: :validate_iso8601_date,
+      semester_end_date: :validate_iso8601_date
     }.freeze
 
     attr_accessor :config, :errors
@@ -61,13 +65,15 @@ def validate
         send(validator, key, config[key.to_s]) if @config.key?(key.to_s)
       end
 
+      validate_semester_date_range
+
       raise ConfigValidationError, errors if errors.length.positive?
 
       puts 'Passed Berkeley YAML Config Validations'
     end
 
     def validate_keys!
-      required_keys = %i[baseurl course_department]
+      required_keys = %i[baseurl course_department semester_start_date semester_end_date]
       required_keys.each do |key|
         errors << "#{key} is missing from site config" unless @config.key?(key.to_s)
       end
@@ -95,6 +101,27 @@ def inclusion_validator(key, value)
       allowed = self.class.const_get("VALID_#{key.upcase}")
       errors << "`#{key}` must be one of #{allowed} (not '#{value}')" unless allowed.include?(value)
     end
+
+    def validate_iso8601_date(key, value)
+      return if parse_iso8601_date(value)
+
+      errors << "`#{key}` must be a valid ISO-8601 date string (YYYY-MM-DD), not '#{value}'"
+    end
+
+    def validate_semester_date_range
+      start_date = parse_iso8601_date(config['semester_start_date'])
+      end_date = parse_iso8601_date(config['semester_end_date'])
+      return unless start_date && end_date
+      return unless start_date > end_date
+
+      errors << '`semester_start_date` must be on or before `semester_end_date`'
+    end
+
+    def parse_iso8601_date(value)
+      Date.iso8601(value.to_s)
+    rescue Date::Error
+      nil
+    end
   end
 end
 

_sass/custom/custom.scss

@@ -137,9 +137,34 @@ p.note::before {
     @include btn-color($white, #6929c4);
   }
 
-  .btn-officehours{
-    @include btn-color($white, #009d9a);
-  }
+.btn-officehours{
+  @include btn-color($white, #009d9a);
+}
+
+.archive-banner {
+  display: none;
+  position: fixed;
+  top: 0;
+  right: 0;
+  left: 0;
+  z-index: 999;
+  padding: 0.75rem 1rem;
+  background-color: #d02670;
+  color: #fff;
+  font-weight: 700;
+  text-align: center;
+}
+
+.archive-banner-link,
+.archive-banner-link:visited {
+  color: #fff;
+  font-weight: 700;
+  text-decoration: underline;
+}
+
+body.archive-banner-visible {
+  padding-top: 3rem;
+}
 
 @if $color-scheme == dark {
   @include dark-mode-overrides;

spec/jekyll/config_validator_spec.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_relative '../../_plugins/config_validator'
+
+RSpec.describe Jekyll::ConfigValidator do
+  let(:base_config) do
+    {
+      'baseurl' => '/sp26',
+      'course_department' => 'dsus',
+      'semester_start_date' => '2026-01-21',
+      'semester_end_date' => '2026-05-09'
+    }
+  end
+
+  it 'validates with required semester dates present' do
+    validator = described_class.new(base_config)
+
+    expect { validator.validate }.not_to raise_error
+  end
+
+  it 'requires semester_start_date and semester_end_date' do
+    config = base_config.except('semester_start_date', 'semester_end_date')
+    validator = described_class.new(config)
+
+    expect { validator.validate }
+      .to raise_error(ConfigValidationError, /semester_start_date is missing.*semester_end_date is missing/m)
+  end
+
+  it 'validates ISO-8601 semester dates' do
+    validator = described_class.new(base_config.merge('semester_start_date' => 'spring-2026'))
+
+    expect { validator.validate }
+      .to raise_error(ConfigValidationError, /`semester_start_date` must be a valid ISO-8601 date string/)
+  end
+
+  it 'requires the start date to be on or before the end date' do
+    validator = described_class.new(base_config.merge('semester_start_date' => '2026-06-01'))
+
+    expect { validator.validate }
+      .to raise_error(ConfigValidationError, /`semester_start_date` must be on or before `semester_end_date`/)
+  end
+end