forked from goadesign/goa
/
generator.go
467 lines (422 loc) · 12.4 KB
/
generator.go
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package genmain
import (
"bufio"
"flag"
"fmt"
"go/ast"
"go/parser"
"go/token"
"net"
"os"
"path"
"path/filepath"
"regexp"
"strings"
"text/template"
"github.com/goadesign/goa/design"
"github.com/goadesign/goa/goagen/codegen"
"github.com/goadesign/goa/goagen/utils"
)
//NewGenerator returns an initialized instance of a JavaScript Client Generator
func NewGenerator(options ...Option) *Generator {
g := &Generator{OutDir: "."}
for _, option := range options {
option(g)
}
return g
}
// Generator is the application code generator.
type Generator struct {
API *design.APIDefinition // The API definition
OutDir string // Path to output directory
DesignPkg string // Path to design package, only used to mark generated files.
Target string // Name of generated "app" package
Force bool // Whether to override existing files
Regen bool // Whether to regenerate scaffolding in place, maintaining controller implementation
genfiles []string // Generated files
}
// Generate is the generator entry point called by the meta generator.
func Generate() (files []string, err error) {
var (
outDir, toolDir, designPkg, target, ver string
force, notool, regen bool
)
set := flag.NewFlagSet("main", flag.PanicOnError)
set.StringVar(&outDir, "out", "", "")
set.StringVar(&designPkg, "design", "", "")
set.StringVar(&target, "pkg", "app", "")
set.StringVar(&ver, "version", "", "")
set.StringVar(&toolDir, "tooldir", "tool", "")
set.BoolVar(¬ool, "notool", false, "")
set.BoolVar(&force, "force", false, "")
set.BoolVar(®en, "regen", false, "")
set.Bool("notest", false, "")
set.Parse(os.Args[1:])
if err := codegen.CheckVersion(ver); err != nil {
return nil, err
}
target = codegen.Goify(target, false)
g := &Generator{OutDir: outDir, DesignPkg: designPkg, Target: target, Force: force, Regen: regen, API: design.Design}
return g.Generate()
}
func extractControllerBody(filename string) (map[string]string, []*ast.ImportSpec, error) {
// First check if a file is there. If not, return empty results to let generation proceed.
if _, e := os.Stat(filename); e != nil {
return map[string]string{}, []*ast.ImportSpec{}, nil
}
fset := token.NewFileSet()
pfile, err := parser.ParseFile(fset, filename, nil, parser.ImportsOnly)
if err != nil {
return nil, nil, err
}
f, err := os.Open(filename)
if err != nil {
return nil, nil, err
}
defer f.Close()
var (
inBlock bool
block []string
)
actionImpls := map[string]string{}
scanner := bufio.NewScanner(f)
for scanner.Scan() {
line := scanner.Text()
match := linePattern.FindStringSubmatch(line)
if len(match) == 3 {
switch match[2] {
case "start":
inBlock = true
case "end":
inBlock = false
actionImpls[match[1]] = strings.Join(block, "\n")
block = []string{}
}
continue
}
if inBlock {
block = append(block, line)
}
}
if err := scanner.Err(); err != nil {
return nil, nil, err
}
return actionImpls, pfile.Imports, nil
}
// GenerateController generates the controller corresponding to the given
// resource and returns the generated filename.
func GenerateController(force, regen bool, appPkg, outDir, pkg, name string, r *design.ResourceDefinition) (filename string, err error) {
filename = filepath.Join(outDir, codegen.SnakeCase(name)+".go")
var (
actionImpls map[string]string
extractedImports []*ast.ImportSpec
)
if regen {
actionImpls, extractedImports, err = extractControllerBody(filename)
if err != nil {
return "", err
}
os.Remove(filename)
}
if force {
os.Remove(filename)
}
if _, e := os.Stat(filename); e == nil {
return "", nil
}
if err = os.MkdirAll(outDir, 0755); err != nil {
return "", err
}
var file *codegen.SourceFile
file, err = codegen.SourceFileFor(filename)
if err != nil {
return "", err
}
defer func() {
file.Close()
if err == nil {
err = file.FormatCode()
}
}()
elems := strings.Split(appPkg, "/")
pkgName := elems[len(elems)-1]
var imp string
if _, err := codegen.PackageSourcePath(appPkg); err == nil {
imp = appPkg
} else {
imp, err = codegen.PackagePath(outDir)
if err != nil {
return "", err
}
imp = path.Join(filepath.ToSlash(imp), appPkg)
}
imports := []*codegen.ImportSpec{
codegen.SimpleImport("io"),
codegen.SimpleImport("github.com/goadesign/goa"),
codegen.SimpleImport(imp),
codegen.SimpleImport("golang.org/x/net/websocket"),
}
for _, imp := range extractedImports {
// This may introduce duplicate imports of the defaults, but
// that'll get worked out by Format later.
var cgimp *codegen.ImportSpec
path := strings.Trim(imp.Path.Value, `"`)
if imp.Name != nil {
cgimp = codegen.NewImport(imp.Name.Name, path)
} else {
cgimp = codegen.SimpleImport(path)
}
imports = append(imports, cgimp)
}
funcs := funcMap(pkgName, actionImpls)
if err = file.WriteHeader("", pkg, imports); err != nil {
return "", err
}
if err = file.ExecuteTemplate("controller", ctrlT, funcs, r); err != nil {
return "", err
}
err = r.IterateActions(func(a *design.ActionDefinition) error {
if a.WebSocket() {
return file.ExecuteTemplate("actionWS", actionWST, funcs, a)
}
return file.ExecuteTemplate("action", actionT, funcs, a)
})
if err != nil {
return "", err
}
return
}
// Generate produces the skeleton main.
func (g *Generator) Generate() (_ []string, err error) {
if g.API == nil {
return nil, fmt.Errorf("missing API definition, make sure design is properly initialized")
}
go utils.Catch(nil, func() { g.Cleanup() })
defer func() {
if err != nil {
g.Cleanup()
}
}()
if g.Target == "" {
g.Target = "app"
}
codegen.Reserved[g.Target] = true
mainFile := filepath.Join(g.OutDir, "main.go")
if g.Force {
os.Remove(mainFile)
}
_, err = os.Stat(mainFile)
if err != nil {
// ensure that the output directory exists before creating a new main
if err = os.MkdirAll(g.OutDir, 0755); err != nil {
return nil, err
}
if err = g.createMainFile(mainFile, funcMap(g.Target, nil)); err != nil {
return nil, err
}
}
err = g.API.IterateResources(func(r *design.ResourceDefinition) error {
filename, err := GenerateController(g.Force, g.Regen, g.Target, g.OutDir, "main", r.Name, r)
if err != nil {
return err
}
g.genfiles = append(g.genfiles, filename)
return nil
})
if err != nil {
return
}
return g.genfiles, nil
}
// Cleanup removes all the files generated by this generator during the last invokation of Generate.
func (g *Generator) Cleanup() {
for _, f := range g.genfiles {
os.Remove(f)
}
g.genfiles = nil
}
func (g *Generator) createMainFile(mainFile string, funcs template.FuncMap) (err error) {
var file *codegen.SourceFile
file, err = codegen.SourceFileFor(mainFile)
if err != nil {
return err
}
defer func() {
file.Close()
if err == nil {
err = file.FormatCode()
}
}()
g.genfiles = append(g.genfiles, mainFile)
funcs["getPort"] = func(hostport string) string {
_, port, err := net.SplitHostPort(hostport)
if err != nil {
return "8080"
}
return port
}
outPkg, err := codegen.PackagePath(g.OutDir)
if err != nil {
return err
}
appPkg := path.Join(outPkg, "app")
imports := []*codegen.ImportSpec{
codegen.SimpleImport("time"),
codegen.SimpleImport("github.com/goadesign/goa"),
codegen.SimpleImport("github.com/goadesign/goa/middleware"),
codegen.SimpleImport(appPkg),
}
file.Write([]byte("//go:generate goagen bootstrap -d " + g.DesignPkg + "\n\n"))
if err = file.WriteHeader("", "main", imports); err != nil {
return err
}
data := map[string]interface{}{
"Name": g.API.Name,
"API": g.API,
}
err = file.ExecuteTemplate("main", mainT, funcs, data)
return
}
// tempCount is the counter used to create unique temporary variable names.
var tempCount int
// tempvar generates a unique temp var name.
func tempvar() string {
tempCount++
if tempCount == 1 {
return "c"
}
return fmt.Sprintf("c%d", tempCount)
}
func okResp(a *design.ActionDefinition, appPkg string) map[string]interface{} {
var ok *design.ResponseDefinition
for _, resp := range a.Responses {
if resp.Status == 200 {
ok = resp
break
}
}
if ok == nil {
return nil
}
var mt *design.MediaTypeDefinition
var ok2 bool
if mt, ok2 = design.Design.MediaTypes[design.CanonicalIdentifier(ok.MediaType)]; !ok2 {
return nil
}
view := ok.ViewName
if view == "" {
view = design.DefaultView
}
pmt, _, err := mt.Project(view)
if err != nil {
return nil
}
var typeref string
if pmt.IsError() {
typeref = `goa.ErrInternal("not implemented")`
} else {
name := codegen.GoTypeRef(pmt, pmt.AllRequired(), 1, false)
var pointer string
if strings.HasPrefix(name, "*") {
name = name[1:]
pointer = "*"
}
typeref = fmt.Sprintf("%s%s.%s", pointer, appPkg, name)
if strings.HasPrefix(typeref, "*") {
typeref = "&" + typeref[1:]
}
typeref += "{}"
}
var nameSuffix string
if view != "default" {
nameSuffix = codegen.Goify(view, true)
}
return map[string]interface{}{
"Name": ok.Name + nameSuffix,
"GoType": codegen.GoNativeType(pmt),
"TypeRef": typeref,
}
}
// funcMap creates the funcMap used to render the controller code.
func funcMap(appPkg string, actionImpls map[string]string) template.FuncMap {
return template.FuncMap{
"tempvar": tempvar,
"okResp": okResp,
"targetPkg": func() string { return appPkg },
"actionBody": func(name string) string {
body, ok := actionImpls[name]
if !ok {
return defaultActionBody
}
return body
},
"printResp": func(name string) bool {
_, ok := actionImpls[name]
return !ok
},
}
}
var linePattern = regexp.MustCompile(`^\s*// ([^:]+): (\w+)_implement\s*$`)
const defaultActionBody = `// Put your logic here`
const ctrlT = `// {{ $ctrlName := printf "%s%s" (goify .Name true) "Controller" }}{{ $ctrlName }} implements the {{ .Name }} resource.
type {{ $ctrlName }} struct {
*goa.Controller
}
// New{{ $ctrlName }} creates a {{ .Name }} controller.
func New{{ $ctrlName }}(service *goa.Service) *{{ $ctrlName }} {
return &{{ $ctrlName }}{Controller: service.NewController("{{ $ctrlName }}")}
}
`
const actionT = `
{{- $ctrlName := printf "%s%s" (goify .Parent.Name true) "Controller" -}}
{{- $actionDescr := printf "%s_%s" $ctrlName (goify .Name true) -}}
// {{ goify .Name true }} runs the {{ .Name }} action.
func (c *{{ $ctrlName }}) {{ goify .Name true }}(ctx *{{ targetPkg }}.{{ goify .Name true }}{{ goify .Parent.Name true }}Context) error {
// {{ $actionDescr }}: start_implement
{{ actionBody $actionDescr }}
{{ if printResp $actionDescr }}
{{ $ok := okResp . targetPkg }}{{ if $ok }} res := {{ $ok.TypeRef }}
{{ end }} return {{ if $ok }}ctx.{{ $ok.Name }}(res){{ else }}nil{{ end }}
{{ end }} // {{ $actionDescr }}: end_implement
}
`
const actionWST = `
{{- $ctrlName := printf "%s%s" (goify .Parent.Name true) "Controller" -}}
{{- $actionDescr := printf "%s_%s" $ctrlName (goify .Name true) -}}
// {{ goify .Name true }} runs the {{ .Name }} action.
func (c *{{ $ctrlName }}) {{ goify .Name true }}(ctx *{{ targetPkg }}.{{ goify .Name true }}{{ goify .Parent.Name true }}Context) error {
c.{{ goify .Name true }}WSHandler(ctx).ServeHTTP(ctx.ResponseWriter, ctx.Request)
return nil
}
// {{ goify .Name true }}WSHandler establishes a websocket connection to run the {{ .Name }} action.
func (c *{{ $ctrlName }}) {{ goify .Name true }}WSHandler(ctx *{{ targetPkg }}.{{ goify .Name true }}{{ goify .Parent.Name true }}Context) websocket.Handler {
return func(ws *websocket.Conn) {
// {{ $actionDescr }}: start_implement
{{ actionBody $actionDescr }}
{{ if printResp $actionDescr }}
ws.Write([]byte("{{ .Name }} {{ .Parent.Name }}"))
// Dummy echo websocket server
io.Copy(ws, ws)
{{ end }} // {{ $actionDescr }}: end_implement
}
}`
const mainT = `
func main() {
// Create service
service := goa.New({{ printf "%q" .Name }})
// Mount middleware
service.Use(middleware.RequestID())
service.Use(middleware.LogRequest(true))
service.Use(middleware.ErrorHandler(service, true))
service.Use(middleware.Recover())
{{ $api := .API }}
{{ range $name, $res := $api.Resources }}{{ $name := goify $res.Name true }} // Mount "{{$res.Name}}" controller
{{ $tmp := tempvar }}{{ $tmp }} := New{{ $name }}Controller(service)
{{ targetPkg }}.Mount{{ $name }}Controller(service, {{ $tmp }})
{{ end }}
// Start service
if err := service.ListenAndServe(":{{ getPort .API.Host }}"); err != nil {
service.LogError("startup", "err", err)
}
}
`