Initial commit

loader.go

@@ -0,0 +1,102 @@
+package tl
+
+import (
+	"html/template"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+// Template collection.
+type Collection struct {
+	// Path to the directory with templates.
+	RootDir string
+	// By default, template name is it's path relative to [RootDir].
+	// This prefix will be prepended to a template name: Prefix + "/" + RelativePath.
+	// You can leave it empty, then it will be ignored.
+	Prefix string
+}
+
+// Advanced options.
+type Options struct {
+	// Files from shared collections will be available in every main template.
+	SharedCollections []Collection
+}
+
+// Load templates from specified directories with default options.
+// Files from the main collection will be added to the returned map.
+func Load(mainCollection Collection) (map[string]*template.Template, error) {
+	return LoadWithOptions(mainCollection, Options{})
+}
+
+// Load templates from specified directories.
+// Files from [mainTemplates] collection will be added to the returned map.
+func LoadWithOptions(
+	mainCollection Collection,
+	options Options,
+) (map[string]*template.Template, error) {
+	sharedTemplate := template.New("")
+	for _, stp := range options.SharedCollections {
+		files, err := getFiles(stp.RootDir, stp.Prefix)
+		if err != nil {
+			return nil, err
+		}
+
+		for name, contents := range files {
+			sharedTemplate, err = sharedTemplate.New(name).Parse(contents)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	templateFiles, err := getFiles(mainCollection.RootDir, mainCollection.Prefix)
+	if err != nil {
+		return nil, err
+	}
+
+	res := make(map[string]*template.Template)
+	for name, contents := range templateFiles {
+		clone, err := sharedTemplate.Clone()
+		if err != nil {
+			return nil, err
+		}
+
+		res[name], err = clone.New(name).Parse(contents)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return res, nil
+}
+
+func getFiles(root string, keyPrefix string) (map[string]string, error) {
+	res := make(map[string]string)
+	if !strings.HasSuffix(root, "/") {
+		root += "/"
+	}
+
+	err := filepath.WalkDir(root, func(entrypath string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if d.IsDir() {
+			return nil
+		}
+
+		shortPath := path.Join(keyPrefix, strings.TrimPrefix(entrypath, root))
+		contents, err := os.ReadFile(entrypath)
+		if err != nil {
+			return err
+		}
+
+		res[shortPath] = string(contents)
+		return nil
+	})
+
+	return res, err
+}