add AssetTemplate

tmpl.go

@@ -1,8 +1,10 @@
 package web
 
 import (
+	"fmt"
 	"html/template"
 	"path/filepath"
+	"sync"
 )
 
 // TemplateGetter defines what needs to be implemented to be able to fetch
@@ -22,3 +24,53 @@ func (d Disk) Get(name string) (*template.Template, error) {
 	p := filepath.Join(d.Root, name+".html")
 	return template.New("").ParseFiles(p, filepath.Join(d.Root, "base.html"))
 }
+
+// AssetTemplate pulls templates from an assetfs.
+type AssetTemplate struct {
+	sync.RWMutex
+	Asset func(name string) ([]byte, error)
+
+	cache map[string]*template.Template
+}
+
+// NewAssetTemplate returns a ready-to-use AssetTemplate.
+func NewAssetTemplate(asset func(string) ([]byte, error)) *AssetTemplate {
+	return &AssetTemplate{
+		Asset: asset,
+		cache: map[string]*template.Template{},
+	}
+}
+
+// Get attempts to merge the requested name+.html with base.html found at root.
+func (at *AssetTemplate) Get(name string) (*template.Template, error) {
+	at.RLock()
+	if t, ok := at.cache[name]; ok {
+		at.RUnlock()
+		return t, nil
+	}
+	at.RUnlock()
+
+	base, err := at.Asset("templates/base.html")
+	if err != nil {
+		return nil, fmt.Errorf("could not get base contents: %v", err)
+	}
+	page, err := at.Asset(fmt.Sprintf("templates/%s.html", name))
+	if err != nil {
+		return nil, fmt.Errorf("could not get base contents: %v", err)
+	}
+
+	t, err := template.New(name).Parse(string(base))
+	if err != nil {
+		return t, fmt.Errorf("parsing base: %v", err)
+	}
+	t, err = t.Parse(string(page))
+	if err != nil {
+		return t, fmt.Errorf("parsing specific page %s: %v", name, err)
+	}
+
+	at.Lock()
+	at.cache[name] = t
+	at.Unlock()
+
+	return t, nil
+}

web.go

@@ -33,6 +33,7 @@ func NewSite(sm *http.ServeMux, static, templates string) *Site {
 		}
 	}
 
+	s.tmpl = NewAssetTemplate(Asset)
 	if templates != "" {
 		s.tmpl = Disk{templates}
 	}