1 files changed, 114 insertions, 0 deletions

diff --git a/echo/template_renderer.go b/echo/template_renderer.go
new file mode 100644
index 0000000..0bafd92
--- /dev/null
+++ b/echo/template_renderer.go
@@ -0,0 +1,114 @@
+package echo
+
+import (
+        "html/template"
+        "io"
+        "net/http"
+        "os"
+        "path/filepath"
+
+        "github.com/labstack/echo/v4"
+)
+
+type TemplateChecker interface {
+        HaveTemplate(echo.Context, string) bool
+}
+
+type TemplateRenderer struct {
+        path  string
+        glob  string
+        funcs template.FuncMap
+        cache *template.Template
+}
+
+func NewTemplateRenderer(path, glob string, funcs template.FuncMap) (*TemplateRenderer, error) {
+        var err error
+
+        r := &TemplateRenderer{path: path, glob: glob, funcs: funcs}
+        r.cache, err = r.loadTemplates()
+        if err != nil {
+                return nil, err
+        }
+
+        return r, nil
+}
+
+func (r *TemplateRenderer) loadTemplates() (*template.Template, error) {
+        t := template.New("").Funcs(r.funcs)
+
+        err := filepath.Walk(r.path, func(path string, info os.FileInfo, err error) error {
+                if err != nil {
+                        return err
+                }
+
+                if !info.IsDir() {
+                        _, fn := filepath.Split(path)
+                        if ok, _ := filepath.Match(r.glob, fn); ok {
+                                fc, err := os.ReadFile(path)
+                                if err != nil {
+                                        return err
+                                }
+
+                                rp, err := filepath.Rel(r.path, path)
+                                if err != nil {
+                                        return err
+                                }
+
+                                _, err = t.New(rp).Parse(string(fc))
+                                if err != nil {
+                                        return err
+                                }
+                        }
+                }
+
+                return nil
+        })
+        if err != nil {
+                return nil, err
+        }
+
+        return t, nil
+}
+
+func (r *TemplateRenderer) getTemplateCache(ctx echo.Context) (*template.Template, error) {
+        var err error
+
+        tc := r.cache
+        if ctx.Echo().Debug {
+                tc, err = r.loadTemplates()
+                if err != nil {
+                        return nil, err
+                }
+        }
+
+        return tc, nil
+}
+
+func (r *TemplateRenderer) Render(w io.Writer, name string, data interface{}, ctx echo.Context) error {
+        tc, err := r.getTemplateCache(ctx)
+        if err != nil {
+                return err
+        }
+
+        if tc.Lookup(name) == nil {
+                return echo.NewHTTPError(http.StatusNotFound, "Page not found")
+        }
+
+        if err := tc.ExecuteTemplate(w, name, data); err != nil {
+                return err
+        }
+
+        return nil
+}
+
+func (r *TemplateRenderer) HaveTemplate(ctx echo.Context, name string) bool {
+        tc, err := r.getTemplateCache(ctx)
+        if err != nil {
+                return false
+        }
+
+        return tc.Lookup(name) != nil
+}
+
+var _ echo.Renderer = (*TemplateRenderer)(nil)
+var _ TemplateChecker = (*TemplateRenderer)(nil)