Full support of the http.FileSystem on all view engines as requested at #1575

Also, the HandleDir accepts both string and http.FileSystem (interface{}) (like the view's fs)

view/jet.go

@@ -3,8 +3,7 @@ package view
 import (
 	"fmt"
 	"io"
-	"os"
-	"path"
+	"net/http"
 	"path/filepath"
 	"reflect"
 	"strings"
@@ -18,9 +17,10 @@ const jetEngineName = "jet"
 
 // JetEngine is the jet template parser's view engine.
 type JetEngine struct {
-	directory string
+	fs        http.FileSystem
+	rootDir   string
 	extension string
-	// physical system files or app-embedded, see `Binary(..., ...)`. Defaults to file system on initialization.
+
 	loader jet.Loader
 
 	developmentMode bool
@@ -51,11 +51,12 @@ var jetExtensions = [...]string{
 
 // Jet creates and returns a new jet view engine.
 // The given "extension" MUST begin with a dot.
-func Jet(directory, extension string) *JetEngine {
-	// if _, err := os.Stat(directory); os.IsNotExist(err) {
-	// 	panic(err)
-	// }
-
+//
+// Usage:
+// Jet("./views", ".jet") or
+// Jet(iris.Dir("./views"), ".jet") or
+// Jet(AssetFile(), ".jet") for embedded data.
+func Jet(fs interface{}, extension string) *JetEngine {
 	extOK := false
 	for _, ext := range jetExtensions {
 		if ext == extension {
@@ -69,9 +70,9 @@ func Jet(directory, extension string) *JetEngine {
 	}
 
 	s := &JetEngine{
-		directory:         directory,
+		rootDir:           "/",
 		extension:         extension,
-		loader:            jet.NewOSFileSystemLoader(directory),
+		loader:            &jetLoader{fs: getFS(fs)},
 		jetDataContextKey: "_jet",
 	}
 
@@ -83,6 +84,13 @@ func (s *JetEngine) String() string {
 	return jetEngineName
 }
 
+// RootDir sets the directory to be used as a starting point
+// to load templates from the provided file system.
+func (s *JetEngine) RootDir(root string) *JetEngine {
+	s.rootDir = filepath.ToSlash(root)
+	return s
+}
+
 // Ext should return the final file extension which this view engine is responsible to render.
 func (s *JetEngine) Ext() string {
 	return s.extension
@@ -175,121 +183,27 @@ func (s *JetEngine) Reload(developmentMode bool) *JetEngine {
 }
 
 // SetLoader can be used when the caller wants to use something like
-// multi.Loader or httpfs.Loader of the jet subpackages,
-// overrides any previous loader may set by `Binary` or the default.
-// Should act before `Load` or `iris.Application#RegisterView`.
+// multi.Loader or httpfs.Loader.
 func (s *JetEngine) SetLoader(loader jet.Loader) *JetEngine {
 	s.loader = loader
 	return s
 }
 
-// Binary optionally, use it when template files are distributed
-// inside the app executable (.go generated files).
-//
-// The assetFn and namesFn can come from the go-bindata library.
-// Should act before `Load` or `iris.Application#RegisterView`.
-func (s *JetEngine) Binary(assetFn func(name string) ([]byte, error), assetNames func() []string) *JetEngine {
-	// embedded.
-	vdir := s.directory
-
-	if vdir[0] == '.' {
-		vdir = vdir[1:]
-	}
-
-	// second check for /something, (or ./something if we had dot on 0 it will be removed)
-	if vdir[0] == '/' || vdir[0] == os.PathSeparator {
-		vdir = vdir[1:]
-	}
-
-	// check for trailing slashes because new users may be do that by mistake
-	// although all examples are showing the correct way but you never know
-	// i.e "./assets/" is not correct, if was inside "./assets".
-	// remove last "/".
-	if trailingSlashIdx := len(vdir) - 1; vdir[trailingSlashIdx] == '/' {
-		vdir = vdir[0:trailingSlashIdx]
-	}
-
-	namesSlice := assetNames()
-	names := make(map[string]struct{})
-	for _, name := range namesSlice {
-		if !strings.HasPrefix(name, vdir) {
-			continue
-		}
-
-		extOK := false
-		fileExt := path.Ext(name)
-		for _, ext := range jetExtensions {
-			if ext == fileExt {
-				extOK = true
-				break
-			}
-		}
-
-		if !extOK {
-			continue
-		}
-
-		names[name] = struct{}{}
-	}
-
-	if len(names) == 0 {
-		panic("JetEngine.Binary: no embedded files found in directory: " + vdir)
-	}
-
-	s.loader = &embeddedLoader{
-		vdir:  vdir,
-		asset: assetFn,
-		names: names,
-	}
-	return s
+type jetLoader struct {
+	fs http.FileSystem
 }
 
-type (
-	embeddedLoader struct {
-		vdir  string
-		asset func(name string) ([]byte, error)
-		names map[string]struct{}
-	}
-	embeddedFile struct {
-		contents []byte // the contents are NOT consumed.
-		readen   int64
-	}
-)
+var _ jet.Loader = (*jetLoader)(nil)
 
-var (
-	_ jet.Loader    = (*embeddedLoader)(nil)
-	_ io.ReadCloser = (*embeddedFile)(nil)
-)
-
-func (f *embeddedFile) Close() error { return nil }
-func (f *embeddedFile) Read(p []byte) (int, error) {
-	if f.readen >= int64(len(f.contents)) {
-		return 0, io.EOF
-	}
-
-	n := copy(p, f.contents[f.readen:])
-	f.readen += int64(n)
-	return n, nil
-}
-
-// Open opens a file from OS file system.
-func (l *embeddedLoader) Open(name string) (io.ReadCloser, error) {
-	name = path.Join(l.vdir, filepath.ToSlash(name))
-	contents, err := l.asset(name)
-	if err != nil {
-		return nil, err
-	}
-	return &embeddedFile{
-		contents: contents,
-	}, nil
+// Open opens a file from file system.
+func (l *jetLoader) Open(name string) (io.ReadCloser, error) {
+	return l.fs.Open(name)
 }
 
 // Exists checks if the template name exists by walking the list of template paths
 // returns string with the full path of the template and bool true if the template file was found
-func (l *embeddedLoader) Exists(name string) (string, bool) {
-	name = path.Join(l.vdir, filepath.ToSlash(name))
-
-	if _, ok := l.names[name]; ok {
+func (l *jetLoader) Exists(name string) (string, bool) {
+	if _, err := l.fs.Open(name); err == nil {
 		return name, true
 	}