Added support for structured template layout

internal/app/app.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"html/template"
+	"io"
 	"io/fs"
 	"net/http"
 	"os"
@@ -49,8 +50,9 @@ type App struct {
 	appDef           *starlarkstruct.Struct
 	errorHandler     starlark.Callable
 	appRouter        *chi.Mux
-	usesHtmlTemplate bool // Whether the app uses HTML templates, false if only JSON APIs
-	template         *template.Template
+	usesHtmlTemplate bool                          // Whether the app uses HTML templates, false if only JSON APIs
+	template         *template.Template            // unstructured templates, no base_templates defined
+	templateMap      map[string]*template.Template // structured templates, base_templates defined
 	watcher          *fsnotify.Watcher
 	sseListeners     []chan SSEMessage
 	funcMap          template.FuncMap
@@ -243,9 +245,43 @@ func (a *App) Reload(force, immediate bool) (bool, error) {
 
 	// Parse HTML templates if there are HTML routes
 	if a.usesHtmlTemplate {
-		if a.template, err = a.sourceFS.ParseFS(a.funcMap, a.Config.Routing.TemplateLocations...); err != nil {
+		baseFiles, err := a.sourceFS.Glob(path.Join(a.Config.Routing.BaseTemplates, "*.go.html"))
+		if err != nil {
 			return false, err
 		}
+
+		if len(baseFiles) == 0 {
+			// No base templates found, use the default unstructured templates
+			if a.template, err = a.sourceFS.ParseFS(a.funcMap, a.Config.Routing.TemplateLocations...); err != nil {
+				return false, err
+			}
+		} else {
+			// Base templates found, using structured templates
+			base, err := a.sourceFS.ParseFS(a.funcMap, baseFiles...)
+			if err != nil {
+				return false, err
+			}
+
+			a.templateMap = make(map[string]*template.Template)
+			for _, paths := range a.Config.Routing.TemplateLocations {
+				files, err := a.sourceFS.Glob(paths)
+				if err != nil {
+					return false, err
+				}
+
+				for _, file := range files {
+					tmpl, err := base.Clone()
+					if err != nil {
+						return false, err
+					}
+
+					a.templateMap[file], err = tmpl.ParseFS(a.sourceFS.ReadableFS, file)
+					if err != nil {
+						return false, err
+					}
+				}
+			}
+		}
 	}
 	a.initialized = true
 
@@ -255,6 +291,40 @@ func (a *App) Reload(force, immediate bool) (bool, error) {
 	return true, nil
 }
 
+func (a *App) executeTemplate(w io.Writer, template, partial string, data any) error {
+	var err error
+	if a.template != nil {
+		exec := partial
+		if partial == "" {
+			exec = template
+		}
+		if err = a.template.ExecuteTemplate(w, exec, data); err != nil {
+			return err
+		}
+	} else {
+		if template == "" {
+			if _, ok := a.templateMap[partial]; ok {
+				template = partial
+			} else {
+				template = "index.go.html"
+			}
+		}
+
+		t, ok := a.templateMap[template]
+		if !ok {
+			return fmt.Errorf("template %s not found", template)
+		}
+		exec := partial
+		if partial == "" {
+			exec = template
+		}
+		if err = t.ExecuteTemplate(w, exec, data); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
 func (a *App) loadSchemaInfo(sourceFS *util.SourceFs) error {
 	// Load the schema info
 	schemaInfoData, err := sourceFS.ReadFile(util.SCHEMA_FILE_NAME)

internal/app/handler.go

@@ -238,7 +238,7 @@ func (a *App) createHandlerFunc(html, block string, handler starlark.Callable, r
 		var err error
 		if isHtmxRequest && block != "" {
 			a.Trace().Msgf("Rendering block %s", block)
-			err = a.template.ExecuteTemplate(w, block, requestData)
+			err = a.executeTemplate(w, html, block, requestData)
 		} else {
 			referrer := r.Header.Get("Referer")
 			isUpdateRequest := r.Method != http.MethodGet && r.Method != http.MethodHead && r.Method != http.MethodOptions
@@ -250,7 +250,7 @@ func (a *App) createHandlerFunc(html, block string, handler starlark.Callable, r
 				return
 			} else {
 				a.Trace().Msgf("Rendering page %s", html)
-				err = a.template.ExecuteTemplate(w, html, requestData)
+				err = a.executeTemplate(w, html, "", requestData)
 			}
 		}
 
@@ -392,7 +392,7 @@ func (a *App) handleResponse(retStruct *starlarkstruct.Struct, r *http.Request,
 		return true, nil
 	}
 	w.WriteHeader(int(code))
-	err = a.template.ExecuteTemplate(w, templateBlock, requestData)
+	err = a.executeTemplate(w, "", templateBlock, requestData)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return true, nil

internal/app/tests/tmpl_test.go

@@ -0,0 +1,96 @@
+// Copyright (c) ClaceIO, LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package app_test
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/claceio/clace/internal/testutil"
+)
+
+func TestBaseTemplate(t *testing.T) {
+	logger := testutil.TestLogger()
+	fileData := map[string]string{
+		"app.star": `
+app = ace.app("testApp", custom_layout=True, pages = [ace.page("/")])
+
+def handler(req):
+	return {"key": "myvalue"}`,
+		"index.go.html":              `ABC {{.Data.key}} {{- template "base" . -}}`,
+		"base_templates/aaa.go.html": `{{define "base"}} aaa{{end}}`,
+	}
+	a, _, err := CreateTestAppRoot(logger, fileData)
+	if err != nil {
+		t.Fatalf("Error %s", err)
+	}
+
+	request := httptest.NewRequest("GET", "/", nil)
+	response := httptest.NewRecorder()
+	a.ServeHTTP(response, request)
+
+	testutil.AssertEqualsInt(t, "code", 200, response.Code)
+	testutil.AssertEqualsString(t, "body", "ABC myvalue aaa", response.Body.String())
+}
+
+func TestBaseTemplateResponse(t *testing.T) {
+	logger := testutil.TestLogger()
+	fileData := map[string]string{
+		"app.star": `
+app = ace.app("testApp", custom_layout=True, pages = [ace.page("/")])
+
+def handler(req):
+	return ace.response({"key": "myvalue"}, "index.go.html")`,
+		"index.go.html":              `ABC {{.Data.key}} {{- template "base" . -}}`,
+		"base_templates/aaa.go.html": `{{define "base"}} aaa{{end}}`,
+	}
+	a, _, err := CreateTestAppRoot(logger, fileData)
+	if err != nil {
+		t.Fatalf("Error %s", err)
+	}
+
+	request := httptest.NewRequest("GET", "/", nil)
+	response := httptest.NewRecorder()
+	a.ServeHTTP(response, request)
+
+	testutil.AssertEqualsInt(t, "code", 200, response.Code)
+	testutil.AssertEqualsString(t, "body", "ABC myvalue aaa", response.Body.String())
+}
+
+func TestBaseTemplateComplete(t *testing.T) {
+	logger := testutil.TestLogger()
+	fileData := map[string]string{
+		"app.star": `
+app = ace.app("testApp", custom_layout=True, pages = [
+	ace.page("/"),
+	ace.page("/second", "second.go.html"),
+	])
+
+def handler(req):
+	return {}`,
+		"index.go.html":               `{{define "body"}} indexbody {{end}} {{- template "full" . -}}`,
+		"second.go.html":              `{{define "body"}} secondbody {{end}} {{- template "full" . -}}`,
+		"base_templates/head.go.html": `{{define "head"}} <head></head>{{end}}`,
+		"base_templates/foot.go.html": `{{define "footer"}} <footer></footer>{{end}}`,
+		"base_templates/full.go.html": `{{define "full"}} <html>{{template "head" .}}{{block "body" .}}{{end}}{{template "footer" .}}</html>{{end}}`,
+	}
+	a, _, err := CreateTestAppRoot(logger, fileData)
+	if err != nil {
+		t.Fatalf("Error %s", err)
+	}
+
+	request := httptest.NewRequest("GET", "/", nil)
+	response := httptest.NewRecorder()
+	a.ServeHTTP(response, request)
+
+	testutil.AssertEqualsInt(t, "code", 200, response.Code)
+	testutil.AssertStringMatch(t, "body", "<html> <head></head> indexbody  <footer></footer></html>", response.Body.String())
+
+	request = httptest.NewRequest("GET", "/second", nil)
+	response = httptest.NewRecorder()
+	a.ServeHTTP(response, request)
+
+	testutil.AssertEqualsInt(t, "code", 200, response.Code)
+	testutil.AssertStringMatch(t, "body", "<html> <head></head> secondbody  <footer></footer></html>", response.Body.String())
+}

internal/app/util/appconfig.go

@@ -10,6 +10,7 @@ type AppConfig struct {
 
 type RouteConfig struct {
 	TemplateLocations []string `json:"template_locations"`
+	BaseTemplates     string   `json:"base_templates"`
 	StaticDir         string   `json:"static_dir"`
 	StaticRootDir     string   `json:"static_root_dir"`
 	PushEvents        bool     `json:"push_events"`
@@ -28,6 +29,7 @@ func NewAppConfig() *AppConfig {
 	return &AppConfig{
 		Routing: RouteConfig{
 			TemplateLocations: []string{"*.go.html"},
+			BaseTemplates:     "base_templates",
 			StaticDir:         "static",
 			StaticRootDir:     "static_root",
 			PushEvents:        false,

tests/testapp/config_gen.lock

@@ -3,6 +3,7 @@
     "template_locations": [
       "*.go.html"
     ],
+    "base_templates": "base_templates",
     "static_dir": "static",
     "static_root_dir": "static_root",
     "push_events": false,