Use a general approach to access custom/static/builtin assets (#24022)

The idea is to use a Layered Asset File-system (modules/assetfs/layered.go)

For example: when there are 2 layers: "custom", "builtin", when access
to asset "my/page.tmpl", the Layered Asset File-system will first try to
use "custom" assets, if not found, then use "builtin" assets.

This approach will hugely simplify a lot of code, make them testable.

Other changes:

* Simplify the AssetsHandlerFunc code
* Simplify the `gitea embedded` sub-command code

---------

Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

1 files changed, 3 insertions, 22 deletions

diff --git a/modules/options/dynamic.go b/modules/options/dynamic.go
index 3d6261983f..085492d11c 100644
--- a/modules/options/dynamic.go
+++ b/modules/options/dynamic.go
@@ -6,29 +6,10 @@
 package options
 
 import (
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/setting"
 )
 
-// Dir returns all files from static or custom directory.
-func Dir(name string) ([]string, error) {
-	if directories.Filled(name) {
-		return directories.Get(name), nil
-	}
-
-	result, err := listLocalDirIfExist([]string{setting.CustomPath, setting.StaticRootPath}, "options", name)
-	if err != nil {
-		return nil, err
-	}
-
-	return directories.AddAndGet(name, result), nil
-}
-
-// fileFromOptionsDir is a helper to read files from custom or static path.
-func fileFromOptionsDir(elems ...string) ([]byte, error) {
-	return readLocalFile([]string{setting.CustomPath, setting.StaticRootPath}, "options", elems...)
-}
-
-// IsDynamic will return false when using embedded data (-tags bindata)
-func IsDynamic() bool {
-	return true
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Local("builtin(static)", setting.StaticRootPath, "options")
 }