examples/entcpkg: add graph function to example (#1326)

examples/entcpkg/ent/debug.go

@@ -15,3 +15,11 @@ func (c *UserClient) Debug() *UserClient {
 	cfg := config{driver: dialect.Debug(c.driver, c.log), log: c.log, debug: true, hooks: c.hooks}
 	return &UserClient{config: cfg}
 }
+
+func (c *UserClient) DebugLog(fn func(...interface{})) *UserClient {
+	if c.debug {
+		return c
+	}
+	cfg := config{driver: dialect.Debug(c.driver, c.log), log: fn, debug: true, hooks: c.hooks}
+	return &UserClient{config: cfg}
+}

examples/entcpkg/ent/entc.go

@@ -7,6 +7,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"strings"
 	"text/template"
@@ -18,9 +19,9 @@ 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` option.
+	// rest are provided with the `Templates` option.
 	opts := []entc.Option{
-		entc.TemplateFiles("template/debug.tmpl"),
+		entc.TemplateFiles("template/stringer.tmpl"),
 	}
 	err := entc.Generate("./schema", &gen.Config{
 		Header: `
@@ -34,9 +35,22 @@ func main() {
 			gen.MustParse(gen.NewTemplate("static").
 				Funcs(template.FuncMap{"title": strings.ToTitle}).
 				ParseFiles("template/static.tmpl")),
+			gen.MustParse(gen.NewTemplate("debug").
+				Funcs(template.FuncMap{"byName": byName}).
+				ParseFiles("template/debug.tmpl")),
 		},
 	}, opts...)
 	if err != nil {
 		log.Fatalf("running ent codegen: %v", err)
 	}
 }
+
+// byName returns a node in the graph by its label/name.
+func byName(g *gen.Graph, name string) (*gen.Type, error) {
+	for _, n := range g.Nodes {
+		if n.Name == name {
+			return n, nil
+		}
+	}
+	return nil, fmt.Errorf("node %q was not found in the graph", name)
+}

examples/entcpkg/ent/template/debug.tmpl

@@ -1,13 +1,13 @@
 {{ 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 functionality for running each client <T> in debug mode. */}}
 
-{{/* Add the base header for the generated file */}}
+{{/* Add the base header for the generated file. */}}
 {{ $pkg := base $.Config.Package }}
 {{ template "header" $ }}
 
-{{/* Loop over all nodes and add option the "Debug()" method */}}
+{{/* Loop over all nodes and add option the "Debug()" method. */}}
 {{ range $n := $.Nodes }}
 	{{ $client := print $n.Name "Client" }}
 	func (c *{{ $client }}) Debug() *{{ $client }} {
@@ -19,4 +19,16 @@
 	}
 {{ end }}
 
+{{/* Add the "DebugLog()" only to the "User" type. */}}
+{{ with $n := byName $ "User" }}
+	{{ $client := print $n.Name "Client" }}
+	func (c *{{ $client }}) DebugLog(fn func(...interface{})) *{{ $client }} {
+		if c.debug {
+			return c
+		}
+		cfg := config{driver: dialect.Debug(c.driver, c.log), log: fn, debug: true, hooks: c.hooks}
+		return &{{ $client }}{config: cfg}
+	}
+{{ end }}
+
 {{ end }}

examples/entcpkg/ent/template/stringer.tmpl

@@ -0,0 +1,13 @@
+{{ define "model/additional/stringer" }}
+
+{{/* A template that adds the "GoString" method to all generated models on the same file they are defined. */}}
+
+// GoString implements the fmt.GoStringer interface.
+func ({{ $.Receiver  }} *{{ $.Name }}) GoString() string {
+	json, err := json.MarshalIndent({{ $.Receiver  }}, "", "\t")
+	if err != nil {
+		return err.Error()
+	}
+	return string(json)
+}
+{{ end }}

examples/entcpkg/ent/user.go

@@ -7,6 +7,7 @@
 package ent
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 
@@ -84,6 +85,15 @@ func (u *User) String() string {
 	return builder.String()
 }
 
+// GoString implements the fmt.GoStringer interface.
+func (u *User) GoString() string {
+	json, err := json.MarshalIndent(u, "", "\t")
+	if err != nil {
+		return err.Error()
+	}
+	return string(json)
+}
+
 // Users is a parsable slice of User.
 type Users []*User
 

examples/entcpkg/example_test.go

@@ -27,5 +27,6 @@ func Example_EntcPkg() {
 	}
 	usr := client.User.Create().SaveX(ctx)
 	fmt.Println("boring user:", usr)
+
 	// Output: boring user: User(id=1)
 }