Improve language handling in URLs

The current "rendering language" is needed outside of Site. This commit moves the Language type to the helpers package, and then used to get correct correct language configuration in the markdownify template func.
This commit also adds two new template funcs: relLangURL and absLangURL.

See #2309

1 files changed, 40 insertions, 13 deletions

diff --git a/helpers/url.go b/helpers/url.go
index 085f9e9fa..f9a41dde3 100644
--- a/helpers/url.go
+++ b/helpers/url.go
@@ -147,18 +147,18 @@ func MakePermalink(host, plink string) *url.URL {
 }
 
 // AbsURL creates a absolute URL from the relative path given and the BaseURL set in config.
-func AbsURL(path string) string {
-	url, err := url.Parse(path)
+func AbsURL(in string, addLanguage bool) string {
+	url, err := url.Parse(in)
 	if err != nil {
-		return path
+		return in
 	}
 
-	if url.IsAbs() || strings.HasPrefix(path, "//") {
-		return path
+	if url.IsAbs() || strings.HasPrefix(in, "//") {
+		return in
 	}
 
 	baseURL := viper.GetString("BaseURL")
-	if strings.HasPrefix(path, "/") {
+	if strings.HasPrefix(in, "/") {
 		p, err := url.Parse(baseURL)
 		if err != nil {
 			panic(err)
@@ -166,7 +166,23 @@ func AbsURL(path string) string {
 		p.Path = ""
 		baseURL = p.String()
 	}
-	return MakePermalink(baseURL, path).String()
+
+	if addLanguage {
+		addSlash := in == "" || strings.HasSuffix(in, "/")
+		in = path.Join(getLanguagePrefix(), in)
+
+		if addSlash {
+			in += "/"
+		}
+	}
+	return MakePermalink(baseURL, in).String()
+}
+
+func getLanguagePrefix() string {
+	if !viper.GetBool("Multilingual") {
+		return ""
+	}
+	return viper.Get("CurrentContentLanguage").(*Language).Lang
 }
 
 // IsAbsURL determines whether the given path points to an absolute URL.
@@ -182,23 +198,34 @@ func IsAbsURL(path string) bool {
 
 // RelURL creates a URL relative to the BaseURL root.
 // Note: The result URL will not include the context root if canonifyURLs is enabled.
-func RelURL(path string) string {
+func RelURL(in string, addLanguage bool) string {
 	baseURL := viper.GetString("BaseURL")
 	canonifyURLs := viper.GetBool("canonifyURLs")
-	if (!strings.HasPrefix(path, baseURL) && strings.HasPrefix(path, "http")) || strings.HasPrefix(path, "//") {
-		return path
+	if (!strings.HasPrefix(in, baseURL) && strings.HasPrefix(in, "http")) || strings.HasPrefix(in, "//") {
+		return in
 	}
 
-	u := path
+	u := in
 
-	if strings.HasPrefix(path, baseURL) {
+	if strings.HasPrefix(in, baseURL) {
 		u = strings.TrimPrefix(u, baseURL)
 	}
 
+	if addLanguage {
+		hadSlash := strings.HasSuffix(u, "/")
+
+		u = path.Join(getLanguagePrefix(), u)
+
+		if hadSlash {
+			u += "/"
+		}
+	}
+
 	if !canonifyURLs {
 		u = AddContextRoot(baseURL, u)
 	}
-	if path == "" && !strings.HasSuffix(u, "/") && strings.HasSuffix(baseURL, "/") {
+
+	if in == "" && !strings.HasSuffix(u, "/") && strings.HasSuffix(baseURL, "/") {
 		u += "/"
 	}