Allow cascade to be a slice with a _target discriminator

Fixes #7782

5 files changed, 152 insertions, 11 deletions

diff --git a/hugolib/cascade_test.go b/hugolib/cascade_test.go
index 33fc7ceec..336acdcf3 100644
--- a/hugolib/cascade_test.go
+++ b/hugolib/cascade_test.go
@@ -229,7 +229,7 @@ Banner: post.jpg`,
 
 		counters := &testCounters{}
 		b.Build(BuildCfg{testCounters: counters})
-		// As we only changed the content, not the cascade front matter, make
+		// As we only changed the content, not the cascade front matter,
 		// only the home page is re-rendered.
 		b.Assert(int(counters.contentRenderCounter), qt.Equals, 1)
 
@@ -392,3 +392,71 @@ defaultContentLanguageInSubDir = false
 
 	return b
 }
+
+func TestCascadeTarget(t *testing.T) {
+	t.Parallel()
+
+	c := qt.New(t)
+
+	newBuilder := func(c *qt.C) *sitesBuilder {
+		b := newTestSitesBuilder(c)
+
+		b.WithTemplates("index.html", `
+{{ $p1 := site.GetPage "s1/p1" }}
+{{ $s1 := site.GetPage "s1" }}
+
+P1|p1:{{ $p1.Params.p1 }}|p2:{{ $p1.Params.p2 }}|
+S1|p1:{{ $s1.Params.p1 }}|p2:{{ $s1.Params.p2 }}|
+`)
+		b.WithContent("s1/_index.md", "---\ntitle: s1 section\n---")
+		b.WithContent("s1/p1/index.md", "---\ntitle: p1\n---")
+		b.WithContent("s1/p2/index.md", "---\ntitle: p2\n---")
+		b.WithContent("s2/p1/index.md", "---\ntitle: p1_2\n---")
+
+		return b
+
+	}
+
+	c.Run("slice", func(c *qt.C) {
+		b := newBuilder(c)
+		b.WithContent("_index.md", `+++
+title = "Home"
+[[cascade]]
+p1 = "p1"
+[[cascade]]
+p2 = "p2"
++++
+`)
+
+		b.Build(BuildCfg{})
+
+		b.AssertFileContent("public/index.html", "P1|p1:p1|p2:p2")
+
+	})
+
+	c.Run("slice with _target", func(c *qt.C) {
+		b := newBuilder(c)
+
+		b.WithContent("_index.md", `+++
+title = "Home"
+[[cascade]]
+p1 = "p1"
+[cascade._target]
+path="**p1**"
+[[cascade]]
+p2 = "p2"
+[cascade._target]
+kind="section"
++++
+`)
+
+		b.Build(BuildCfg{})
+
+		b.AssertFileContent("public/index.html", `
+P1|p1:p1|p2:|
+S1|p1:|p2:p2|
+`)
+
+	})
+
+}
diff --git a/hugolib/content_map_page.go b/hugolib/content_map_page.go
index b32f808c9..b2a8fda7e 100644
--- a/hugolib/content_map_page.go
+++ b/hugolib/content_map_page.go
@@ -789,7 +789,7 @@ func (m *pageMaps) withMaps(fn func(pm *pageMap) error) error {
 
 type pagesMapBucket struct {
 	// Cascading front matter.
-	cascade maps.Params
+	cascade map[page.PageMatcher]maps.Params
 
 	owner *pageState // The branch node
 
diff --git a/hugolib/page__meta.go b/hugolib/page__meta.go
index 0e16292f0..c7a8db3d5 100644
--- a/hugolib/page__meta.go
+++ b/hugolib/page__meta.go
@@ -308,12 +308,22 @@ func (p *pageMeta) Weight() int {
 
 func (pm *pageMeta) mergeBucketCascades(b1, b2 *pagesMapBucket) {
 	if b1.cascade == nil {
-		b1.cascade = make(map[string]interface{})
+		b1.cascade = make(map[page.PageMatcher]maps.Params)
 	}
+
 	if b2 != nil && b2.cascade != nil {
 		for k, v := range b2.cascade {
-			if _, found := b1.cascade[k]; !found {
+
+			vv, found := b1.cascade[k]
+			if !found {
 				b1.cascade[k] = v
+			} else {
+				// Merge
+				for ck, cv := range v {
+					if _, found := vv[ck]; !found {
+						vv[ck] = cv
+					}
+				}
 			}
 		}
 	}
@@ -332,14 +342,44 @@ func (pm *pageMeta) setMetadata(parentBucket *pagesMapBucket, p *pageState, fron
 		if p.bucket != nil {
 			// Check for any cascade define on itself.
 			if cv, found := frontmatter["cascade"]; found {
-				p.bucket.cascade = maps.ToStringMap(cv)
+				switch v := cv.(type) {
+				case []map[string]interface{}:
+					p.bucket.cascade = make(map[page.PageMatcher]maps.Params)
+
+					for _, vv := range v {
+						var m page.PageMatcher
+						if mv, found := vv["_target"]; found {
+							err := page.DecodePageMatcher(mv, &m)
+							if err != nil {
+								return err
+							}
+						}
+						c, found := p.bucket.cascade[m]
+						if found {
+							// Merge
+							for k, v := range vv {
+								if _, found := c[k]; !found {
+									c[k] = v
+								}
+							}
+						} else {
+							p.bucket.cascade[m] = vv
+						}
+
+					}
+				default:
+					p.bucket.cascade = map[page.PageMatcher]maps.Params{
+						page.PageMatcher{}: maps.ToStringMap(cv),
+					}
+				}
+
 			}
 		}
 	} else {
 		frontmatter = make(map[string]interface{})
 	}
 
-	var cascade map[string]interface{}
+	var cascade map[page.PageMatcher]maps.Params
 
 	if p.bucket != nil {
 		if parentBucket != nil {
@@ -351,9 +391,14 @@ func (pm *pageMeta) setMetadata(parentBucket *pagesMapBucket, p *pageState, fron
 		cascade = parentBucket.cascade
 	}
 
-	for k, v := range cascade {
-		if _, found := frontmatter[k]; !found {
-			frontmatter[k] = v
+	for m, v := range cascade {
+		if !m.Matches(p) {
+			continue
+		}
+		for kk, vv := range v {
+			if _, found := frontmatter[kk]; !found {
+				frontmatter[kk] = vv
+			}
 		}
 	}
 
@@ -466,7 +511,7 @@ func (pm *pageMeta) setMetadata(parentBucket *pagesMapBucket, p *pageState, fron
 		case "outputs":
 			o := cast.ToStringSlice(v)
 			if len(o) > 0 {
-				// Output formats are exlicitly set in front matter, use those.
+				// Output formats are explicitly set in front matter, use those.
 				outFormats, err := p.s.outputFormatsConfig.GetByNames(o...)
 
 				if err != nil {
diff --git a/hugolib/page_test.go b/hugolib/page_test.go
index 2df679a74..3a30216ed 100644
--- a/hugolib/page_test.go
+++ b/hugolib/page_test.go
@@ -1757,3 +1757,24 @@ $$$
 		`<pre><code class="language-bash {hl_lines=[1]}" data-lang="bash {hl_lines=[1]}">SHORT`,
 	)
 }
+
+func TestPageCaseIssues(t *testing.T) {
+	t.Parallel()
+
+	b := newTestSitesBuilder(t)
+	b.WithConfigFile("toml", `defaultContentLanguage = "no"
+[languages]
+[languages.NO]
+title = "Norsk"
+`)
+	b.WithContent("a/B/C/Page1.md", "---\ntitle: Page1\n---")
+	b.WithTemplates("index.html", `
+{{ $p1 := site.GetPage "a/B/C/Page1" }}
+Lang: {{ .Lang }}
+Page1: {{ $p1.Path }}
+`)
+
+	b.Build(BuildCfg{})
+
+	b.AssertFileContent("public/index.html", "Lang: no", filepath.FromSlash("Page1: a/B/C/Page1.md"))
+}
diff --git a/hugolib/pages_capture.go b/hugolib/pages_capture.go
index ddb4bc495..4ee33992d 100644
--- a/hugolib/pages_capture.go
+++ b/hugolib/pages_capture.go
@@ -137,6 +137,7 @@ func (c *pagesCollector) isCascadingEdit(dir contentDirKey) (bool, string) {
 		hasCascade := n.p.bucket.cascade != nil && len(n.p.bucket.cascade) > 0
 		if !ok {
 			isCascade = hasCascade
+
 			return true
 		}
 
@@ -145,7 +146,12 @@ func (c *pagesCollector) isCascadingEdit(dir contentDirKey) (bool, string) {
 			return true
 		}
 
-		isCascade = !reflect.DeepEqual(cascade1, n.p.bucket.cascade)
+		for _, v := range n.p.bucket.cascade {
+			isCascade = !reflect.DeepEqual(cascade1, v)
+			if isCascade {
+				break
+			}
+		}
 
 		return true
 
@@ -187,6 +193,7 @@ func (c *pagesCollector) Collect() (collectErr error) {
 				collectErr = c.collectDir(dir.dirname, true, nil)
 			case bundleBranch:
 				isCascading, section := c.isCascadingEdit(dir)
+
 				if isCascading {
 					c.contentMap.deleteSection(section)
 				}