From e3690c8743eec1bfdc8fc000e83e0ba66b46e6b5 Mon Sep 17 00:00:00 2001
From: Johan Lindh <johan@linkdata.se>
Date: Thu, 14 Nov 2024 13:51:57 +0100
Subject: [PATCH] add MakeAuth hook fn

---
 auth.go          |  9 +++++++++
 jaws.go          |  1 +
 template.go      |  5 +++++
 template_test.go |  1 -
 testjaws_test.go | 20 ++++++++++++++++++++
 with.go          |  3 ++-
 6 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 auth.go

diff --git a/auth.go b/auth.go
new file mode 100644
index 0000000..37bd3f5
--- /dev/null
+++ b/auth.go
@@ -0,0 +1,9 @@
+package jaws
+
+type Auth interface {
+	Data() map[string]any // returns authenticated user data, or nil
+	Email() string        // returns authenticated user email, or an empty string
+	IsAdmin() bool        // return true if admins are defined and current user is one
+}
+
+type MakeAuthFn func(*Request) Auth
diff --git a/jaws.go b/jaws.go
index fda902b..2167d40 100644
--- a/jaws.go
+++ b/jaws.go
@@ -44,6 +44,7 @@ type Jaws struct {
 	CookieName   string       // Name for session cookies, defaults to "jaws"
 	Logger       *slog.Logger // Optional logger to use
 	Debug        bool         // Set to true to enable debug info in generated HTML code
+	MakeAuth     MakeAuthFn   // Optional function to create With.Auth for Templates
 	doneCh       <-chan struct{}
 	bcastCh      chan Message
 	subCh        chan subscription
diff --git a/template.go b/template.go
index f1012fa..fae8e8f 100644
--- a/template.go
+++ b/template.go
@@ -29,11 +29,16 @@ func (t Template) JawsRender(e *Element, wr io.Writer, params []any) error {
 	e.Tag(tags...)
 	e.handlers = append(e.handlers, handlers...)
 	attrstr := template.HTMLAttr(strings.Join(attrs, " ")) // #nosec G203
+	var auth Auth
+	if f := e.Request.Jaws.MakeAuth; f != nil {
+		auth = f(e.Request)
+	}
 	return e.Request.Jaws.LookupTemplate(t.Name).Execute(wr, With{
 		Element:       e,
 		RequestWriter: e.Request.Writer(wr),
 		Dot:           t.Dot,
 		Attrs:         attrstr,
+		Auth:          auth,
 	})
 }
 
diff --git a/template_test.go b/template_test.go
index dbd651a..29e2573 100644
--- a/template_test.go
+++ b/template_test.go
@@ -18,7 +18,6 @@ func TestTemplate_String(t *testing.T) {
 func TestTemplate_Calls_Dot_Updater(t *testing.T) {
 	rq := newTestRequest()
 	defer rq.Close()
-
 	dot := &testUi{}
 	tmpl := NewTemplate("testtemplate", dot)
 	tmpl.JawsUpdate(nil)
diff --git a/testjaws_test.go b/testjaws_test.go
index ec24801..4c00e4e 100644
--- a/testjaws_test.go
+++ b/testjaws_test.go
@@ -16,11 +16,31 @@ type testJaws struct {
 	log      bytes.Buffer
 }
 
+type testAuth struct{}
+
+// Data implements Auth.
+func (t testAuth) Data() map[string]any {
+	return nil
+}
+
+// Email implements Auth.
+func (t testAuth) Email() string {
+	return ""
+}
+
+// IsAdmin implements Auth.
+func (t testAuth) IsAdmin() bool {
+	return false
+}
+
 func newTestJaws() (tj *testJaws) {
 	tj = &testJaws{
 		Jaws: New(),
 	}
 	tj.Jaws.Logger = slog.New(slog.NewTextHandler(&tj.log, nil))
+	tj.Jaws.MakeAuth = func(r *Request) Auth {
+		return testAuth{}
+	}
 	tj.testtmpl = template.Must(template.New("testtemplate").Parse(`{{with $.Dot}}<div id="{{$.Jid}}" {{$.Attrs}}>{{.}}</div>{{end}}`))
 	tj.AddTemplateLookuper(tj.testtmpl)
 	tj.Jaws.updateTicker = time.NewTicker(time.Millisecond)
diff --git a/with.go b/with.go
index 855fa33..f39619d 100644
--- a/with.go
+++ b/with.go
@@ -5,10 +5,11 @@ import (
 )
 
 // With is passed as the data parameter when using RequestWriter.Template(),
-// populated with all members set.
+// populated with all required members set.
 type With struct {
 	*Element                        // the Element being rendered using a template.
 	RequestWriter                   // the RequestWriter
 	Dot           any               // user data parameter
 	Attrs         template.HTMLAttr // HTML attributes string
+	Auth          Auth              // (optional) authentication information returned by MakeAuthFn
 }