Add support for URL locale filter to target specific locale

_config.yml

@@ -73,17 +73,14 @@ defaults:
       path: 'content/_en'
     values:
       lang: en
-      base_path: ''
   - scope:
       path: 'content/_es'
     values:
       lang: es
-      base_path: /es
   - scope:
       path: 'content/_fr'
     values:
       lang: fr
-      base_path: /fr
 
 include:
   # dotfiles are excluded by default

_includes/language_picker.html

@@ -24,26 +24,7 @@
   >
     {% for locale in site.languages %}
       <li>
-        {% if page.lang == 'en' %}
-          {% if locale == 'en' %}
-            {% assign locale_url = page.url %}
-          {% elsif locale == page.lang %}
-            {% assign locale_url = page.url %}
-          {% else %}
-            {% assign locale_url = page.url | prepend: locale | prepend: '/' %}
-          {% endif %}
-        {% else %}
-          {% if locale == 'en' and page.lang == 'es' %}
-            {% assign locale_url = page.url | remove_first: 'es/' %}
-          {% elsif locale == 'en' and page.lang == 'fr' %}
-            {% assign locale_url = page.url | remove_first: 'fr/' %}
-          {% elsif locale == page.lang %}
-            {% assign locale_url = page.url %}
-          {% else %}
-            {% assign locale_url = page.url | replace_first: page.lang, locale %}
-          {% endif %}
-        {% endif %}
-        <a href="{{ locale_url | prepend: site.baseurl }}" lang="{{ locale }}">
+        <a href="{{ page.url | delocalize_url | locale_url: locale }}" lang="{{ locale }}">
           {{ site.data.[locale].settings.global.locales[locale] }}
         </a>
       </li>

_plugins/locale_url_filter.rb

@@ -2,14 +2,23 @@ module Jekyll
   module LocaleUrlFilter
     LOCALE_STRING_CONSTANT = '__LOCALE_BASE_URL__'.freeze
 
-    def locale_url(path = '')
+    def locale_url(path = '', locale = nil)
       site_base_url = @context.registers[:site].baseurl
-      locale_prefix = @context.registers[:page]['base_path']
-      site_base_url.to_s + locale_prefix.to_s + path
+      locale ||= @context.registers[:page]['lang']
+      permalink = @context.registers[:site].collections[locale].metadata['permalink']
+      site_base_url.to_s + Jekyll::URL.new(
+        template: permalink,
+        placeholders: { collection: locale, path: path },
+      ).to_s
+    end
+
+    def delocalize_url(path, locale = nil)
+      locale ||= @context.registers[:page]['lang']
+      path.gsub(%r{^/#{locale}/}, '/')
     end
 
     def replace_locale_base_url(input)
-      input.gsub LOCALE_STRING_CONSTANT, locale_url
+      input.gsub(LOCALE_STRING_CONSTANT, locale_url.chomp('/'))
     end
   end
 end

spec/_plugins/locale_url_filter_spec.rb

@@ -0,0 +1,278 @@
+require 'jekyll'
+require './_plugins/locale_url_filter'
+
+class JekyllFilter
+  include Jekyll::LocaleUrlFilter
+
+  def initialize(config, page_data)
+    @site = Jekyll::Site.new(Jekyll::Configuration.from(config))
+    page = Jekyll::Page.new(@site, @site.source, '', 'README.md')
+    page.data.merge!(page_data)
+    @context = Liquid::Context.new(@site.site_payload, {}, site: @site, page: page)
+  end
+end
+
+RSpec.describe Jekyll::LocaleUrlFilter do
+  let(:config) { {} }
+  let(:page_data) { { 'lang' => 'en' } }
+  let(:instance) { JekyllFilter.new(config, page_data) }
+
+  describe '#locale_url' do
+    let(:path) { '' }
+    let(:locale) { nil }
+    subject(:locale_url) { instance.locale_url(path, locale) }
+
+    context 'without site base url' do
+      let(:config) do
+        {
+          'collections' => {
+            'en' => { 'permalink' => '/:path/' },
+            'es' => { 'permalink' => '/:path/' },
+          },
+        }
+      end
+
+      context 'without path' do
+        context 'without locale' do
+          it 'renders without locale' do
+            expect(locale_url).to eq('/')
+          end
+        end
+
+        context 'with locale' do
+          let(:locale) { 'es' }
+
+          it 'renders without locale' do
+            expect(locale_url).to eq('/')
+          end
+        end
+      end
+
+      context 'with path' do
+        let(:path) { '/path/' }
+
+        context 'without locale' do
+          it 'renders without locale' do
+            expect(locale_url).to eq('/path/')
+          end
+        end
+
+        context 'with locale' do
+          let(:locale) { 'es' }
+
+          it 'renders without locale' do
+            expect(locale_url).to eq('/path/')
+          end
+        end
+      end
+    end
+
+    context 'with collection in permalink' do
+      let(:config) do
+        {
+          'collections' => {
+            'en' => { 'permalink' => '/:collection/:path/' },
+            'es' => { 'permalink' => '/:collection/:path/' },
+          },
+        }
+      end
+
+      context 'without path' do
+        context 'without locale' do
+          it 'renders with locale from page data' do
+            expect(locale_url).to eq('/en/')
+          end
+        end
+
+        context 'with locale' do
+          let(:locale) { 'es' }
+
+          it 'renders with locale' do
+            expect(locale_url).to eq('/es/')
+          end
+        end
+      end
+
+      context 'with path' do
+        let(:path) { '/path/' }
+
+        context 'without locale' do
+          it 'renders without locale' do
+            expect(locale_url).to eq('/en/path/')
+          end
+        end
+
+        context 'with locale' do
+          let(:locale) { 'es' }
+
+          it 'renders without locale' do
+            expect(locale_url).to eq('/es/path/')
+          end
+        end
+      end
+    end
+
+    context 'with site base url' do
+      context 'without collection in permalink' do
+        let(:config) do
+          {
+            'baseurl' => 'https://example.com',
+            'collections' => {
+              'en' => { 'permalink' => '/:path/' },
+              'es' => { 'permalink' => '/:path/' },
+            },
+          }
+        end
+
+        context 'without path' do
+          context 'without locale' do
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/')
+            end
+          end
+
+          context 'with locale' do
+            let(:locale) { 'es' }
+
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/')
+            end
+          end
+        end
+
+        context 'with path' do
+          let(:path) { '/path/' }
+
+          context 'without locale' do
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/path/')
+            end
+          end
+
+          context 'with locale' do
+            let(:locale) { 'es' }
+
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/path/')
+            end
+          end
+        end
+      end
+
+      context 'with collection in permalink' do
+        let(:config) do
+          {
+            'baseurl' => 'https://example.com',
+            'collections' => {
+              'en' => { 'permalink' => '/:collection/:path/' },
+              'es' => { 'permalink' => '/:collection/:path/' },
+            },
+          }
+        end
+
+        context 'without path' do
+          context 'without locale' do
+            it 'renders with locale from page data' do
+              expect(locale_url).to eq('https://example.com/en/')
+            end
+          end
+
+          context 'with locale' do
+            let(:locale) { 'es' }
+
+            it 'renders with locale' do
+              expect(locale_url).to eq('https://example.com/es/')
+            end
+          end
+        end
+
+        context 'with path' do
+          let(:path) { '/path/' }
+
+          context 'without locale' do
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/en/path/')
+            end
+          end
+
+          context 'with locale' do
+            let(:locale) { 'es' }
+
+            it 'renders without locale' do
+              expect(locale_url).to eq('https://example.com/es/path/')
+            end
+          end
+        end
+      end
+    end
+  end
+
+  describe '#delocalize_url' do
+    let(:path) { '' }
+    let(:locale) { nil }
+    let(:page_data) { { 'lang' => 'es' } }
+    subject(:delocalized_url) { instance.delocalize_url(path, locale) }
+
+    context 'path not including locale' do
+      let(:path) { '/fr/example/' }
+
+      context 'without locale' do
+        it 'uses page data and does not modify path' do
+          expect(delocalized_url).to eq(path)
+        end
+      end
+
+      context 'with locale' do
+        let(:locale) { 'es' }
+
+        it 'does not modify path' do
+          expect(delocalized_url).to eq(path)
+        end
+      end
+    end
+
+    context 'path including locale' do
+      let(:path) { '/es/example/' }
+
+      context 'without locale' do
+        it 'uses page data and delocalizes url' do
+          expect(delocalized_url).to eq('/example/')
+        end
+      end
+
+      context 'with locale' do
+        let(:locale) { 'es' }
+
+        it 'delocalizes url' do
+          expect(delocalized_url).to eq('/example/')
+        end
+      end
+    end
+  end
+
+  describe '#replace_locale_base_url' do
+    let(:input) { "#{Jekyll::LocaleUrlFilter::LOCALE_STRING_CONSTANT}/help/" }
+    subject(:locale_url) { instance.replace_locale_base_url(input) }
+
+    context 'without site base url' do
+      let(:config) { { 'collections' => { 'en' => { 'permalink' => '/:path/' } } } }
+
+      it 'replaces using page data' do
+        expect(locale_url).to eq('/help/')
+      end
+    end
+
+    context 'with site base url' do
+      let(:config) do
+        {
+          'baseurl' => 'https://example.com',
+          'collections' => { 'en' => { 'permalink' => '/:path/' } },
+        }
+      end
+
+      it 'replaces using page data' do
+        expect(locale_url).to eq('https://example.com/help/')
+      end
+    end
+  end
+end