hugolib: Add optional outputFormat to Ref/RelRef

Fixes #3224

5 files changed, 88 insertions, 27 deletions

diff --git a/hugolib/page.go b/hugolib/page.go
index 7b7d8d655..00646d27d 100644
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -1522,12 +1522,24 @@ func (p *Page) RSSlink() template.URL {
 	return p.RSSLink()
 }
 
-func (p *Page) Ref(ref string) (string, error) {
-	return p.Site.Ref(ref, nil)
+func (p *Page) Ref(refs ...string) (string, error) {
+	if len(refs) == 0 {
+		return "", nil
+	}
+	if len(refs) > 1 {
+		return p.Site.Ref(refs[0], nil, refs[1])
+	}
+	return p.Site.Ref(refs[0], nil)
 }
 
-func (p *Page) RelRef(ref string) (string, error) {
-	return p.Site.RelRef(ref, nil)
+func (p *Page) RelRef(refs ...string) (string, error) {
+	if len(refs) == 0 {
+		return "", nil
+	}
+	if len(refs) > 1 {
+		return p.Site.RelRef(refs[0], nil, refs[1])
+	}
+	return p.Site.RelRef(refs[0], nil)
 }
 
 func (p *Page) String() string {
diff --git a/hugolib/page_output.go b/hugolib/page_output.go
index 58d09d688..c6a72d324 100644
--- a/hugolib/page_output.go
+++ b/hugolib/page_output.go
@@ -243,9 +243,8 @@ func (p *Page) AlternativeOutputFormats() (OutputFormats, error) {
 // Get gets a OutputFormat given its name, i.e. json, html etc.
 // It returns nil if not found.
 func (o OutputFormats) Get(name string) *OutputFormat {
-	name = strings.ToLower(name)
 	for _, f := range o {
-		if strings.ToLower(f.f.Name) == name {
+		if strings.EqualFold(f.f.Name, name) {
 			return f
 		}
 	}
diff --git a/hugolib/permalinker.go b/hugolib/permalinker.go
new file mode 100644
index 000000000..5e7a13a02
--- /dev/null
+++ b/hugolib/permalinker.go
@@ -0,0 +1,25 @@
+// Copyright 2017-present The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache 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://www.apache.org/licenses/LICENSE-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
+
+var (
+	_ Permalinker = (*Page)(nil)
+	_ Permalinker = (*OutputFormat)(nil)
+)
+
+// Permalinker provides permalinks of both the relative and absolute kind.
+type Permalinker interface {
+	Permalink() string
+	RelPermalink() string
+}
diff --git a/hugolib/site.go b/hugolib/site.go
index aefc8c940..7aec4d4d3 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -407,7 +407,7 @@ func (s *SiteInfo) IsMultiLingual() bool {
 	return len(s.Languages) > 1
 }
 
-func (s *SiteInfo) refLink(ref string, page *Page, relative bool) (string, error) {
+func (s *SiteInfo) refLink(ref string, page *Page, relative bool, outputFormat string) (string, error) {
 	var refURL *url.URL
 	var err error
 
@@ -433,10 +433,21 @@ func (s *SiteInfo) refLink(ref string, page *Page, relative bool) (string, error
 			return "", fmt.Errorf("No page found with path or logical name \"%s\".\n", refURL.Path)
 		}
 
+		var permalinker Permalinker = target
+
+		if outputFormat != "" {
+			o := target.OutputFormats().Get(outputFormat)
+
+			if o == nil {
+				return "", fmt.Errorf("Output format %q not found for page %q", outputFormat, refURL.Path)
+			}
+			permalinker = o
+		}
+
 		if relative {
-			link = target.RelPermalink()
+			link = permalinker.RelPermalink()
 		} else {
-			link = target.Permalink()
+			link = permalinker.Permalink()
 		}
 	}
 
@@ -454,13 +465,23 @@ func (s *SiteInfo) refLink(ref string, page *Page, relative bool) (string, error
 }
 
 // Ref will give an absolute URL to ref in the given Page.
-func (s *SiteInfo) Ref(ref string, page *Page) (string, error) {
-	return s.refLink(ref, page, false)
+func (s *SiteInfo) Ref(ref string, page *Page, options ...string) (string, error) {
+	outputFormat := ""
+	if len(options) > 0 {
+		outputFormat = options[0]
+	}
+
+	return s.refLink(ref, page, false, outputFormat)
 }
 
 // RelRef will give an relative URL to ref in the given Page.
-func (s *SiteInfo) RelRef(ref string, page *Page) (string, error) {
-	return s.refLink(ref, page, true)
+func (s *SiteInfo) RelRef(ref string, page *Page, options ...string) (string, error) {
+	outputFormat := ""
+	if len(options) > 0 {
+		outputFormat = options[0]
+	}
+
+	return s.refLink(ref, page, true, outputFormat)
 }
 
 // SourceRelativeLink attempts to convert any source page relative links (like [../another.md]) into absolute links
diff --git a/hugolib/site_test.go b/hugolib/site_test.go
index 5f66b153c..e00e8b230 100644
--- a/hugolib/site_test.go
+++ b/hugolib/site_test.go
@@ -894,10 +894,6 @@ func setupLinkingMockSite(t *testing.T) *Site {
 		{Name: filepath.FromSlash("level2/index.md"), Content: []byte("")},
 		{Name: filepath.FromSlash("level2/common.md"), Content: []byte("")},
 
-		//		{Name: filepath.FromSlash("level2b/2b-root.md"), Content: []byte("")},
-		//		{Name: filepath.FromSlash("level2b/index.md"), Content: []byte("")},
-		//		{Name: filepath.FromSlash("level2b/common.md"), Content: []byte("")},
-
 		{Name: filepath.FromSlash("level2/2-image.png"), Content: []byte("")},
 		{Name: filepath.FromSlash("level2/common.png"), Content: []byte("")},
 
@@ -912,12 +908,14 @@ func setupLinkingMockSite(t *testing.T) *Site {
 
 	cfg.Set("baseURL", "http://auth/")
 	cfg.Set("uglyURLs", false)
+	cfg.Set("outputs", map[string]interface{}{
+		"page": []string{"HTML", "AMP"},
+	})
 	cfg.Set("pluralizeListTitles", false)
 	cfg.Set("canonifyURLs", false)
 	cfg.Set("blackfriday",
 		map[string]interface{}{
 			"sourceRelativeLinksProjectFolder": "/docs"})
-
 	writeSourcesToSource(t, "content", fs, sources...)
 	return buildSingleSite(t, deps.DepsCfg{Fs: fs, Cfg: cfg}, BuildCfg{})
 
@@ -932,19 +930,25 @@ func TestRefLinking(t *testing.T) {
 		t.Fatalf("failed to find current page in site")
 	}
 
-	// refLink doesn't use the location of the current page to work out reflinks
-	okresults := map[string]string{
+	for i, test := range []struct {
+		link         string
+		outputFormat string
+		relative     bool
+		expected     string
+	}{
 		// Note: There are no magic in the index.md name. This was fixed in Hugo 0.20.
 		// Before that, index.md would wrongly resolve to "/".
-		"index.md":  "/index/",
-		"common.md": "/level2/common/",
-		"3-root.md": "/level2/level3/3-root/",
-	}
-	for link, url := range okresults {
-		if out, err := site.Info.refLink(link, currentPage, true); err != nil || out != url {
-			t.Errorf("Expected %s to resolve to (%s), got (%s) - error: %s", link, url, out, err)
+		{"index.md", "", true, "/index/"},
+		{"common.md", "", true, "/level2/common/"},
+		{"3-root.md", "", true, "/level2/level3/3-root/"},
+		{"index.md", "amp", true, "/amp/index/"},
+		{"index.md", "amp", false, "http://auth/amp/index/"},
+	} {
+		if out, err := site.Info.refLink(test.link, currentPage, test.relative, test.outputFormat); err != nil || out != test.expected {
+			t.Errorf("[%d] Expected %s to resolve to (%s), got (%s) - error: %s", i, test.link, test.expected, out, err)
 		}
 	}
+
 	// TODO: and then the failure cases.
 }