add support for the go standard embed tag for locale files

context/context_fs.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/fs"
 	"net/http"
+	"path"
 )
 
 // ResolveFS accepts a single input argument of any type
@@ -44,3 +45,67 @@ var ResolveFS = func(fsOrDir interface{}) http.FileSystem {
 
 	return fileSystem
 }
+
+// FindNames accepts a "http.FileSystem" and a root name and returns
+// the list containg its file names.
+func FindNames(fileSystem http.FileSystem, name string) ([]string, error) {
+	f, err := fileSystem.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	fi, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	if !fi.IsDir() {
+		return []string{name}, nil
+	}
+
+	fileinfos, err := f.Readdir(-1)
+	if err != nil {
+		return nil, err
+	}
+
+	files := make([]string, 0)
+
+	for _, info := range fileinfos {
+		// Note:
+		// go-bindata has absolute names with os.Separator,
+		// http.Dir the basename.
+		filename := toBaseName(info.Name())
+		fullname := path.Join(name, filename)
+		if fullname == name { // prevent looping through itself.
+			continue
+		}
+		rfiles, err := FindNames(fileSystem, fullname)
+		if err != nil {
+			return nil, err
+		}
+
+		files = append(files, rfiles...)
+	}
+
+	return files, nil
+}
+
+// Instead of path.Base(filepath.ToSlash(s))
+// let's do something like that, it is faster
+// (used to list directories on serve-time too):
+func toBaseName(s string) string {
+	n := len(s) - 1
+	for i := n; i >= 0; i-- {
+		if c := s[i]; c == '/' || c == '\\' {
+			if i == n {
+				// "s" ends with a slash, remove it and retry.
+				return toBaseName(s[:n])
+			}
+
+			return s[i+1:] // return the rest, trimming the slash.
+		}
+	}
+
+	return s
+}