entc/gen: improve the api for custom templates

examples/entcpkg/ent/debug.go

@@ -0,0 +1,17 @@
+// Copyright 2019-present Facebook Inc. All rights reserved.
+// This source code is licensed under the Apache 2.0 license found
+// in the LICENSE file in the root directory of this source tree.
+
+// Code generated by entc, DO NOT EDIT.
+
+package ent
+
+import "github.com/facebook/ent/dialect"
+
+func (c *UserClient) Debug() *UserClient {
+	if c.debug {
+		return c
+	}
+	cfg := config{driver: dialect.Debug(c.driver, c.log), log: c.log, debug: true, hooks: c.hooks}
+	return &UserClient{config: cfg}
+}

examples/entcpkg/ent/entc.go

@@ -16,6 +16,13 @@ import (
 )
 
 func main() {
+	// A usage for custom templates with external functions.
+	// One template is defined in the option below, and the
+	// second template is provided with the `Templates` field.
+	opts := []entc.Option{
+		entc.Funcs(template.FuncMap{"title": strings.ToTitle}),
+		entc.TemplateFiles("template/static.tmpl"),
+	}
 	err := entc.Generate("./schema", &gen.Config{
 		Header: `
 			// Copyright 2019-present Facebook Inc. All rights reserved.
@@ -24,11 +31,12 @@ func main() {
 
 			// Code generated by entc, DO NOT EDIT.
 		`,
-		// A usage for custom templates with external functions.
-		Template: template.Must(template.New("template").
-			Funcs(template.FuncMap{"title": strings.ToTitle}).
-			ParseFiles("template/static.tmpl")),
-	})
+		Templates: []*template.Template{
+			template.Must(template.New("debug").
+				Funcs(gen.Funcs).
+				ParseFiles("template/debug.tmpl")),
+		},
+	}, opts...)
 	if err != nil {
 		log.Fatal("running ent codegen:", err)
 	}

examples/entcpkg/ent/template/debug.tmpl

@@ -0,0 +1,22 @@
+{{ define "debug" }}
+
+{{/* A template that will be generated to a file named "debug.go" and
+     add the functionality for running each client <T> in debug mode */}}
+
+{{/* Add the base header for the generated file */}}
+{{ $pkg := base $.Config.Package }}
+{{ template "header" $ }}
+
+{{/* Loop over all nodes and add option the "Debug()" method */}}
+{{ range $n := $.Nodes }}
+	{{ $client := print $n.Name "Client" }}
+	func (c *{{ $client }}) Debug() *{{ $client }} {
+		if c.debug {
+			return c
+		}
+		cfg := config{driver: dialect.Debug(c.driver, c.log), log: c.log, debug: true, hooks: c.hooks}
+		return &{{ $client }}{config: cfg}
+	}
+{{ end }}
+
+{{ end }}