Allow themes to define output formats, media types and params

Fixes gohugoio#4490

Gopkg.toml

@@ -141,3 +141,7 @@
   name = "github.com/muesli/smartcrop"
   branch = "master"
 
+
+[[constraint]]
+  name = "github.com/sanity-io/litter"
+  version = "1.1.0"

commands/hugo.go

@@ -306,7 +306,14 @@ func InitializeConfig(running bool, doWithCommandeer func(c *commandeer) error,
 	// Init file systems. This may be changed at a later point.
 	osFs := hugofs.Os
 
-	config, err := hugolib.LoadConfig(hugolib.ConfigSourceDescriptor{Fs: osFs, Src: source, Name: cfgFile})
+	var dir string
+	if source != "" {
+		dir, _ = filepath.Abs(source)
+	} else {
+		dir, _ = os.Getwd()
+	}
+
+	config, err := hugolib.LoadConfig(hugolib.ConfigSourceDescriptor{Fs: osFs, Src: source, WorkingDir: dir, Name: cfgFile})
 	if err != nil {
 		return nil, err
 	}
@@ -358,12 +365,6 @@ func InitializeConfig(running bool, doWithCommandeer func(c *commandeer) error,
 		config.Set("publishDir", destination)
 	}
 
-	var dir string
-	if source != "" {
-		dir, _ = filepath.Abs(source)
-	} else {
-		dir, _ = os.Getwd()
-	}
 	config.Set("workingDir", dir)
 
 	if contentDir != "" {

helpers/path.go

@@ -154,11 +154,16 @@ func ReplaceExtension(path string, newExt string) string {
 // AbsPathify creates an absolute path if given a relative path. If already
 // absolute, the path is just cleaned.
 func (p *PathSpec) AbsPathify(inPath string) string {
+	return AbsPathify(p.workingDir, inPath)
+}
+
+// AbsPathify creates an absolute path if given a working dir and arelative path.
+// If already absolute, the path is just cleaned.
+func AbsPathify(workingDir, inPath string) string {
 	if filepath.IsAbs(inPath) {
 		return filepath.Clean(inPath)
 	}
-
-	return filepath.Join(p.workingDir, inPath)
+	return filepath.Join(workingDir, inPath)
 }
 
 // GetLayoutDirPath returns the absolute path to the layout file dir

hugolib/config.go

@@ -16,6 +16,7 @@ package hugolib
 import (
 	"errors"
 	"fmt"
+	"path/filepath"
 
 	"io"
 	"strings"
@@ -28,9 +29,10 @@ import (
 
 // ConfigSourceDescriptor describes where to find the config (e.g. config.toml etc.).
 type ConfigSourceDescriptor struct {
-	Fs   afero.Fs
-	Src  string
-	Name string
+	Fs         afero.Fs
+	Src        string
+	WorkingDir string
+	Name       string
 }
 
 func (d ConfigSourceDescriptor) configFilenames() []string {
@@ -85,7 +87,16 @@ func LoadConfig(d ConfigSourceDescriptor) (*viper.Viper, error) {
 		return v, err
 	}
 
+	if err := loadThemeConfig(d, v); err != nil {
+		return v, err
+	}
+
+	if err := loadLanguageSettings(v, nil); err != nil {
+		return v, err
+	}
+
 	return v, nil
+
 }
 
 func loadLanguageSettings(cfg config.Provider, oldLangs helpers.Languages) error {
@@ -201,6 +212,142 @@ func loadLanguageSettings(cfg config.Provider, oldLangs helpers.Languages) error
 	return nil
 }
 
+func loadThemeConfig(d ConfigSourceDescriptor, v1 *viper.Viper) error {
+
+	theme := v1.GetString("theme")
+	if theme == "" {
+		return nil
+	}
+
+	themesDir := helpers.AbsPathify(d.WorkingDir, v1.GetString("themesDir"))
+	configDir := filepath.Join(themesDir, theme)
+
+	var (
+		configPath string
+		exists     bool
+		err        error
+	)
+
+	// Viper supports more, but this is the sub-set supported by Hugo.
+	for _, configFormats := range []string{"toml", "yaml", "yml", "json"} {
+		configPath = filepath.Join(configDir, "config."+configFormats)
+		exists, err = helpers.Exists(configPath, d.Fs)
+		if err != nil {
+			return err
+		}
+		if exists {
+			break
+		}
+	}
+
+	if !exists {
+		// No theme config set.
+		return nil
+	}
+
+	v2 := viper.New()
+	v2.SetFs(d.Fs)
+	v2.AutomaticEnv()
+	v2.SetEnvPrefix("hugo")
+	v2.SetConfigFile(configPath)
+
+	err = v2.ReadInConfig()
+	if err != nil {
+		return err
+	}
+
+	const (
+		paramsKey    = "params"
+		languagesKey = "languages"
+		menuKey      = "menu"
+	)
+
+	for _, key := range []string{"params", "outputformats", "mediatypes"} {
+		mergeStringMapKeepLeft(key, v1, v2)
+	}
+
+	themeLower := strings.ToLower(theme)
+	themeParamsNamespace := paramsKey + "." + themeLower
+	// Set namespaced params
+
+	if v2.IsSet(paramsKey) && !v1.IsSet(themeParamsNamespace) {
+		// Set it in the default store to make sure it gets in the same or
+		// behind the others.
+		v1.SetDefault(themeParamsNamespace, v2.Get(paramsKey))
+	}
+
+	// Only add params and new menu entries, we do not add language definitions.
+	if v1.IsSet(languagesKey) && v2.IsSet(languagesKey) {
+		v1Langs := v1.GetStringMap(languagesKey)
+		for k, _ := range v1Langs {
+			mergeStringMapKeepLeft(languagesKey+"."+k+"."+paramsKey, v1, v2)
+		}
+		v2Langs := v2.GetStringMap(languagesKey)
+		for k, _ := range v2Langs {
+			if k == "" {
+				continue
+			}
+			langParamsKey := languagesKey + "." + k + "." + paramsKey
+			langParamsThemeNamespace := langParamsKey + "." + themeLower
+			// Set namespaced params
+			if v2.IsSet(langParamsKey) && !v1.IsSet(langParamsThemeNamespace) {
+				v1.SetDefault(langParamsThemeNamespace, v2.Get(langParamsKey))
+			}
+
+			langMenuKey := languagesKey + "." + k + "." + menuKey
+			if v2.IsSet(langMenuKey) {
+				// Only add if not in the main config.
+				v2menus := v2.GetStringMap(langMenuKey)
+				for k, v := range v2menus {
+					menuEntry := menuKey + "." + k
+					menuLangEntry := langMenuKey + "." + k
+					if !v1.IsSet(menuEntry) && !v1.IsSet(menuLangEntry) {
+						v1.Set(menuLangEntry, v)
+					}
+				}
+			}
+
+		}
+	}
+
+	// Add menu definitions from theme not found in project
+	if v2.IsSet("menu") {
+		v2menus := v2.GetStringMap(menuKey)
+		for k, v := range v2menus {
+			menuEntry := menuKey + "." + k
+			if !v1.IsSet(menuEntry) {
+				v1.SetDefault(menuEntry, v)
+			}
+		}
+	}
+
+	return nil
+
+}
+
+func mergeStringMapKeepLeft(key string, v1, v2 *viper.Viper) {
+
+	if !v1.IsSet(key) {
+		if v2.IsSet(key) {
+			v1.SetDefault(key, v2.Get(key))
+		}
+		return
+	}
+
+	if !v2.IsSet(key) {
+		return
+	}
+
+	m1 := v1.GetStringMap(key)
+	m2 := v2.GetStringMap(key)
+
+	for k, v := range m2 {
+		if _, found := m1[k]; !found {
+			m1[k] = v
+		}
+	}
+}
+
 func loadDefaultSettingsFor(v *viper.Viper) error {
 
 	c, err := helpers.NewContentSpec(v)
@@ -281,5 +428,5 @@ lastmod = ["lastmod" ,":fileModTime", ":default"]
 
 	}
 
-	return loadLanguageSettings(v, nil)
+	return nil
 }