Adding Prev/Next functionality to all lists of pages (sections, taxonomies, etc)

diff --git a/hugolib/pagesPrevNext.go b/hugolib/pagesPrevNext.go
new file mode 100644 (file)
index 0000000..5a7bc38
--- /dev/null
+++ b/hugolib/pagesPrevNext.go
@@ -0,0 +1,38 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Simple Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://opensource.org/licenses/Simple-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+func (p Pages) Prev(cur *Page) *Page {
+       for x, c := range p {
+               if c.UniqueId() == cur.UniqueId() {
+                       if x == 0 {
+                               return p[len(p)-1]
+                       }
+                       return p[x-1]
+               }
+       }
+       return nil
+}
+
+func (p Pages) Next(cur *Page) *Page {
+       for x, c := range p {
+               if c.UniqueId() == cur.UniqueId() {
+                       if x < len(p)-1 {
+                               return p[x+1]
+                       }
+                       return p[0]
+               }
+       }
+       return nil
+}

diff --git a/hugolib/pagesPrevNext_test.go b/hugolib/pagesPrevNext_test.go
new file mode 100644 (file)
index 0000000..4bcfd6e
--- /dev/null
+++ b/hugolib/pagesPrevNext_test.go
@@ -0,0 +1,96 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Simple Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://opensource.org/licenses/Simple-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+import (
+       "testing"
+
+       "github.com/spf13/cast"
+       "github.com/stretchr/testify/assert"
+)
+
+type pagePNTestObject struct {
+       path   string
+       weight int
+       date   string
+}
+
+var pagePNTestSources = []pagePNTestObject{
+       {"/section1/testpage1.md", 5, "2012-04-06"},
+       {"/section1/testpage2.md", 4, "2012-01-01"},
+       {"/section1/testpage3.md", 3, "2012-04-06"},
+       {"/section2/testpage4.md", 2, "2012-03-02"},
+       {"/section2/testpage5.md", 1, "2012-04-06"},
+}
+
+func preparePagePNTestPages(t *testing.T) Pages {
+       var pages Pages
+       for _, s := range pagePNTestSources {
+               p, err := NewPage(s.path)
+               if err != nil {
+                       t.Fatalf("failed to prepare test page %s", s.path)
+               }
+               p.Weight = s.weight
+               p.Date = cast.ToTime(s.date)
+               p.PublishDate = cast.ToTime(s.date)
+               pages = append(pages, p)
+       }
+       return pages
+}
+
+func TestPrev(t *testing.T) {
+       pages := preparePageGroupTestPages(t)
+       assert.Equal(t, pages.Prev(pages[0]), pages[4])
+       assert.Equal(t, pages.Prev(pages[1]), pages[0])
+       assert.Equal(t, pages.Prev(pages[4]), pages[3])
+}
+
+func TestNext(t *testing.T) {
+       pages := preparePageGroupTestPages(t)
+       assert.Equal(t, pages.Next(pages[0]), pages[1])
+       assert.Equal(t, pages.Next(pages[1]), pages[2])
+       assert.Equal(t, pages.Next(pages[4]), pages[0])
+}
+
+func prepareWeightedPagesPrevNext(t *testing.T) WeightedPages {
+       w := WeightedPages{}
+
+       for _, s := range pagePNTestSources {
+               p, err := NewPage(s.path)
+               if err != nil {
+                       t.Fatalf("failed to prepare test page %s", s.path)
+               }
+               p.Weight = s.weight
+               p.Date = cast.ToTime(s.date)
+               p.PublishDate = cast.ToTime(s.date)
+               w = append(w, WeightedPage{p.Weight, p})
+       }
+
+       w.Sort()
+       return w
+}
+
+func TestWeightedPagesPrev(t *testing.T) {
+       w := prepareWeightedPagesPrevNext(t)
+       assert.Equal(t, w.Prev(w[0].Page), w[4].Page)
+       assert.Equal(t, w.Prev(w[1].Page), w[0].Page)
+       assert.Equal(t, w.Prev(w[4].Page), w[3].Page)
+}
+
+func TestWeightedPagesNext(t *testing.T) {
+       w := prepareWeightedPagesPrevNext(t)
+       assert.Equal(t, w.Next(w[0].Page), w[1].Page)
+       assert.Equal(t, w.Next(w[1].Page), w[2].Page)
+       assert.Equal(t, w.Next(w[4].Page), w[0].Page)
+}

diff --git a/hugolib/taxonomy.go b/hugolib/taxonomy.go
index 93bd78f681ff2302e11aaa7bb8ad0182d796d9b8..fdba1e56efa1ca541312dce6db6956068d924cf9 100644 (file)
--- a/hugolib/taxonomy.go
+++ b/hugolib/taxonomy.go
@@ -160,6 +160,30 @@ func (wp WeightedPages) Pages() Pages {
        return pages
 }
 
+func (wp WeightedPages) Prev(cur *Page) *Page {
+       for x, c := range wp {
+               if c.Page.UniqueId() == cur.UniqueId() {
+                       if x == 0 {
+                               return wp[len(wp)-1].Page
+                       }
+                       return wp[x-1].Page
+               }
+       }
+       return nil
+}
+
+func (wp WeightedPages) Next(cur *Page) *Page {
+       for x, c := range wp {
+               if c.Page.UniqueId() == cur.UniqueId() {
+                       if x < len(wp)-1 {
+                               return wp[x+1].Page
+                       }
+                       return wp[0].Page
+               }
+       }
+       return nil
+}
+
 func (p WeightedPages) Len() int      { return len(p) }
 func (p WeightedPages) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
 func (p WeightedPages) Sort()         { sort.Stable(p) }