sync: Add Init and Sync functions

Init initializes the directory/repository before the first use.
Sync is called to unsure the directory is up-to-date.

admin/sync/importer_localfs.go

@@ -2,6 +2,7 @@ package sync
 
 import (
 	"bufio"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -11,7 +12,7 @@ import (
 // inside a local directory from your filesystem.
 type LocalImporter struct {
 	// Base is the root directory used by the LocalImporter. It should contains all themes.
-	Base    string
+	Base string
 	// Symlink changes the normal file copy/concatenate behaviour to symlink/concatenate.
 	// If enable, your base directory must be accessible by the frontend processus as it will follow the symlink.
 	Symlink bool
@@ -25,6 +26,23 @@ func (i LocalImporter) Kind() string {
 	}
 }
 
+func (i LocalImporter) Init() error {
+	if f, err := os.Stat(i.Base); os.IsNotExist(err) {
+		if err = os.Mkdir(i.Base, 0751); err != nil {
+			return err
+		}
+	} else if err != nil {
+		return err
+	} else if !f.IsDir() {
+		return fmt.Errorf("%q exists and is not a directory", i.Base)
+	}
+	return nil
+}
+
+func (i LocalImporter) Sync() error {
+	return nil
+}
+
 func (i LocalImporter) exists(filename string) bool {
 	_, err := os.Stat(i.toURL(filename))
 	return !os.IsNotExist(err)
@@ -46,7 +64,7 @@ func (i LocalImporter) importFile(URI string, next func(string, string) (interfa
 			os.Symlink(i.toURL(URI), dest)
 			return next(dest, URI)
 		} else {
-			os.Symlink(i.toURL(URI) + "_MERGED", dest)
+			os.Symlink(i.toURL(URI)+"_MERGED", dest)
 			return ImportFile(i, URI, next)
 		}
 	} else {