echo: allow plugins to hook templates

2 files changed, 14 insertions, 0 deletions

diff --git a/echo/echo_default.go b/echo/echo_default.go
index cbe43cb..8440fe2 100644
--- a/echo/echo_default.go
+++ b/echo/echo_default.go
@@ -61,6 +61,7 @@ type EchoConfig struct {
         TrustedProxyIPRanges  []string
         EmbeddedTemplates     fs.FS
         DiskTemplates         fs.FS
+        ProvideTemplateStore  []WantsTemplateStore
         TemplateFunctions     template.FuncMap
         CombinedHostLogFile   string
         RedirectToWWW         bool
@@ -227,6 +228,11 @@ func (w *EchoWrapper) configureTemplates(c *EchoConfig) error {
                 templates = c.EmbeddedTemplates
         }
 
+        // Configure plugins that want access to the template store
+        for _, w := range c.ProvideTemplateStore {
+                w.ConfigureTemplateStore(templates)
+        }
+
         // Only install template handlers if the path is set
         if templates != nil {
                 tr, err := NewTemplateRenderer(templates, "*.tpl", c.TemplateFunctions, w.Debug)
diff --git a/echo/interfaces.go b/echo/interfaces.go
index f3380c6..1f3957a 100644
--- a/echo/interfaces.go
+++ b/echo/interfaces.go
@@ -1,6 +1,8 @@
 package echo
 
 import (
+        "io/fs"
+
         "github.com/labstack/echo/v4"
 )
 
@@ -18,3 +20,9 @@ type URLRouter interface {
         Group(string, ...echo.MiddlewareFunc) *echo.Group
         Add(string, string, echo.HandlerFunc, ...echo.MiddlewareFunc) *echo.Route
 }
+
+// WantsTemplateStore is an interface for template helper functions that
+// need access to the template store for the running echo instance.
+type WantsTemplateStore interface {
+        ConfigureTemplateStore(fs.FS)
+}