init template

loader/chain/loader.go

@@ -0,0 +1,29 @@
+package chain
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"gitoa.ru/go-4devs/templating/loader"
+	"gitoa.ru/go-4devs/templating/render"
+)
+
+var _ loader.Loader = (Loaders)(nil)
+
+type Loaders []loader.Loader
+
+func (l Loaders) Load(ctx context.Context, template render.Reference) (loader.Source, error) {
+	for idx, load := range l {
+		sourse, err := load.Load(ctx, template)
+		if err == nil {
+			return sourse, nil
+		}
+
+		if !errors.Is(err, loader.ErrNotFound) {
+			return loader.Source{}, fmt.Errorf("chain[%d]:%w", idx, err)
+		}
+	}
+
+	return loader.Source{}, fmt.Errorf("chains(%d):%w", len(l), loader.ErrNotFound)
+}

loader/empty.go

@@ -0,0 +1,20 @@
+package loader
+
+import (
+	"context"
+	"fmt"
+
+	"gitoa.ru/go-4devs/templating/render"
+)
+
+var _empty = empty{}
+
+type empty struct{}
+
+func (empty) Load(context.Context, render.Reference) (Source, error) {
+	return Source{}, fmt.Errorf("empty: %w", ErrNotFound)
+}
+
+func Empty() Loader {
+	return _empty
+}

loader/loader.go

@@ -0,0 +1,34 @@
+package loader
+
+import (
+	"context"
+	"errors"
+
+	"gitoa.ru/go-4devs/templating/render"
+)
+
+var ErrNotFound = errors.New("not found")
+
+type Loader interface {
+	Load(ctx context.Context, r render.Reference) (Source, error)
+}
+
+func NewSource(name, data string) Source {
+	return Source{
+		name: name,
+		data: data,
+	}
+}
+
+type Source struct {
+	name string
+	data string
+}
+
+func (s Source) Name() string {
+	return s.name
+}
+
+func (s Source) Data() string {
+	return s.data
+}