Merge pull request #2299 from penibelst/sort-nils

features/embed_filters.feature

@@ -73,3 +73,35 @@ Feature: Embed filters
     Then the _site directory should exist
     And I should see exactly "Page-2, Page-1" in "_site/page-1.html"
     And I should see exactly "Page-2, Page-1" in "_site/page-2.html"
+
+  Scenario: Sort pages by the title
+    Given I have a _layouts directory
+    And I have the following page:
+      | title | layout | content |
+      | Dog | default | Run |
+    And I have the following page:
+      | title | layout | content |
+      | Bird | default | Fly |
+    And I have the following page:
+      | layout | content |
+      | default | Jump |
+    And I have a default layout that contains "{% assign sorted_pages = site.pages | sort: 'title' %}The rule of {{ sorted_pages.size }}: {% for p in sorted_pages %}{{ p.content | strip_html | strip_newlines }}, {% endfor %}"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see exactly "The rule of 3: Jump, Fly, Run," in "_site/bird.html"
+
+  Scenario: Sort pages by the title ordering pages without title last
+    Given I have a _layouts directory
+    And I have the following page:
+      | title | layout | content |
+      | Dog | default | Run |
+    And I have the following page:
+      | title | layout | content |
+      | Bird | default | Fly |
+    And I have the following page:
+      | layout | content |
+      | default | Jump |
+    And I have a default layout that contains "{% assign sorted_pages = site.pages | sort: 'title', 'last' %}The rule of {{ sorted_pages.size }}: {% for p in sorted_pages %}{{ p.content | strip_html | strip_newlines }}, {% endfor %}"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see exactly "The rule of 3: Fly, Run, Jump," in "_site/bird.html"

features/support/env.rb

@@ -28,7 +28,11 @@ def run_jekyll(args)
 end
 
 def slug(title)
+  if title
     title.downcase.gsub(/[^\w]/, " ").strip.gsub(/\s+/, '-')
+  else
+    Time.now.strftime("%s%9N") # nanoseconds since the Epoch
+  end
 end
 
 def location(folder, direction)

lib/jekyll/filters.rb

@@ -190,6 +190,40 @@ module Jekyll
       input.select { |object| object[key] == value }
     end
 
+    # Sort an array of objects
+    #
+    # input - the object array
+    # key - key within each object to filter by
+    # nils ('first' | 'last') - nils appear before or after non-nil values
+    #
+    # Returns the filtered array of objects
+    def sort(input, key = nil, nils = "first")
+      if key.nil?
+        input.sort
+      else
+        case
+        when nils == "first"
+          order = - 1
+        when nils == "last"
+          order = + 1
+        else
+          Jekyll.logger.error "Invalid nils order:",
+            "'#{nils}' is not a valid nils order. It must be 'first' or 'last'."
+          exit(1)
+        end
+
+        input.sort { |a, b|
+          if !a[key].nil? && b[key].nil?
+            - order
+          elsif a[key].nil? && !b[key].nil?
+            + order
+          else
+            a[key] <=> b[key]
+          end
+        }
+      end
+    end
+
     private
     def time(input)
       case input

site/docs/templates.md

@@ -210,6 +210,23 @@ common tasks easier.
         </p>
       </td>
     </tr>
+    <tr>
+      <td>
+        <p class="name"><strong>Sort</strong></p>
+        <p>Sort an array. Optional arguments for hashes: 1.&nbsp;property name 2.&nbsp;nils order (<em>first</em> or <em>last</em>).</p>
+      </td>
+      <td class="align-center">
+        <p>
+         <code class="filter">{% raw %}{{ page.tags | sort }}{% endraw %}</code>
+        </p>
+        <p>
+         <code class="filter">{% raw %}{{ site.posts | sort: 'author' }}{% endraw %}</code>
+        </p>
+        <p>
+         <code class="filter">{% raw %}{{ site.pages | sort: 'title', 'last' }}{% endraw %}</code>
+        </p>
+      </td>
+    </tr>
   </tbody>
 </table>
 </div>

test/test_filters.rb

@@ -152,5 +152,30 @@ class TestFilters < Test::Unit::TestCase
       end
     end
 
+    context "sort filter" do
+      should "return sorted numbers" do
+        assert_equal [1, 2, 2.2, 3], @filter.sort([3, 2.2, 2, 1])
+      end
+      should "return sorted strings" do
+        assert_equal ["10", "2"], @filter.sort(["10", "2"])
+        assert_equal [{"a" => "10"}, {"a" => "2"}], @filter.sort([{"a" => "10"}, {"a" => "2"}], "a")
+        assert_equal ["FOO", "Foo", "foo"], @filter.sort(["foo", "Foo", "FOO"])
+        assert_equal ["_foo", "foo", "foo_"], @filter.sort(["foo_", "_foo", "foo"])
+      end
+      should "return sorted by property array" do
+        assert_equal [{"a" => 1}, {"a" => 2}, {"a" => 3}, {"a" => 4}],
+          @filter.sort([{"a" => 4}, {"a" => 3}, {"a" => 1}, {"a" => 2}], "a")
+      end
+      should "return sorted by property array with nils first" do
+        ary = [{"a" => 2}, {"b" => 1}, {"a" => 1}]
+        assert_equal [{"b" => 1}, {"a" => 1}, {"a" => 2}], @filter.sort(ary, "a")
+        assert_equal @filter.sort(ary, "a"), @filter.sort(ary, "a", "first")
+      end
+      should "return sorted by property array with nils last" do
+        assert_equal [{"a" => 1}, {"a" => 2}, {"b" => 1}],
+          @filter.sort([{"a" => 2}, {"b" => 1}, {"a" => 1}], "a", "last")
+      end
+    end
+
   end
 end