tpl: Rework to handle both text and HTML templates

Before this commit, Hugo used `html/template` for all Go templates.

While this is a fine choice for HTML and maybe also RSS feeds, it is painful for plain text formats such as CSV, JSON etc.

This commit fixes that by using the `IsPlainText` attribute on the output format to decide what to use.

A couple of notes:

* The above requires a nonambiguous template name to type mapping. I.e. `/layouts/_default/list.json` will only work if there is only one JSON output format, `/layouts/_default/list.mytype.json` will always work.
* Ambiguous types will fall back to HTML.
* Partials inherits the text vs HTML identificator of the container template. This also means that plain text templates can only include plain text partials.
* Shortcode templates are, by definition, currently HTML templates only.

Fixes #3221

1 files changed, 26 insertions, 1 deletions

diff --git a/output/outputFormat_test.go b/output/outputFormat_test.go
index e742012ba..b73e53f82 100644
--- a/output/outputFormat_test.go
+++ b/output/outputFormat_test.go
@@ -65,7 +65,7 @@ func TestDefaultTypes(t *testing.T) {
 
 }
 
-func TestGetType(t *testing.T) {
+func TestGetFormat(t *testing.T) {
 	tp, _ := GetFormat("html")
 	require.Equal(t, HTMLFormat, tp)
 	tp, _ = GetFormat("HTML")
@@ -73,3 +73,28 @@ func TestGetType(t *testing.T) {
 	_, found := GetFormat("FOO")
 	require.False(t, found)
 }
+
+func TestGeGetFormatByName(t *testing.T) {
+	formats := Formats{AMPFormat, CalendarFormat}
+	tp, _ := formats.GetByName("AMP")
+	require.Equal(t, AMPFormat, tp)
+	_, found := formats.GetByName("HTML")
+	require.False(t, found)
+	_, found = formats.GetByName("FOO")
+	require.False(t, found)
+}
+
+func TestGeGetFormatByExt(t *testing.T) {
+	formats1 := Formats{AMPFormat, CalendarFormat}
+	formats2 := Formats{AMPFormat, HTMLFormat, CalendarFormat}
+	tp, _ := formats1.GetBySuffix("html")
+	require.Equal(t, AMPFormat, tp)
+	tp, _ = formats1.GetBySuffix("ics")
+	require.Equal(t, CalendarFormat, tp)
+	_, found := formats1.GetBySuffix("not")
+	require.False(t, found)
+
+	// ambiguous
+	_, found = formats2.GetByName("html")
+	require.False(t, found)
+}