ref: 2b8e8e6d9619af2095bff9e27b3b486cd4fc4b4c
dir: /tpl/tplimpl/template.go/
// Copyright 2019 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tplimpl
import (
"io"
"os"
"path/filepath"
"reflect"
"regexp"
"strings"
"sync"
"time"
"unicode"
"unicode/utf8"
"github.com/gohugoio/hugo/common/types"
"github.com/gohugoio/hugo/helpers"
"github.com/gohugoio/hugo/output"
"github.com/gohugoio/hugo/deps"
"github.com/spf13/afero"
"github.com/gohugoio/hugo/common/herrors"
"github.com/gohugoio/hugo/hugofs"
"github.com/gohugoio/hugo/hugofs/files"
"github.com/pkg/errors"
"github.com/gohugoio/hugo/tpl/tplimpl/embedded"
htmltemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/htmltemplate"
texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/tpl"
)
const (
textTmplNamePrefix = "_text/"
shortcodesPathPrefix = "shortcodes/"
internalPathPrefix = "_internal/"
baseFileBase = "baseof"
)
// The identifiers may be truncated in the log, e.g.
// "executing "main" at <$scaled.SRelPermalin...>: can't evaluate field SRelPermalink in type *resource.Image"
var identifiersRe = regexp.MustCompile(`at \<(.*?)(\.{3})?\>:`)
var embeddedTemplatesAliases = map[string][]string{
"shortcodes/twitter.html": {"shortcodes/tweet.html"},
}
var (
_ tpl.TemplateManager = (*templateExec)(nil)
_ tpl.TemplateHandler = (*templateExec)(nil)
_ tpl.TemplateFuncGetter = (*templateExec)(nil)
_ tpl.TemplateFinder = (*templateExec)(nil)
_ tpl.Template = (*templateState)(nil)
_ tpl.Info = (*templateState)(nil)
)
var baseTemplateDefineRe = regexp.MustCompile(`^{{-?\s*define`)
// needsBaseTemplate returns true if the first non-comment template block is a
// define block.
// If a base template does not exist, we will handle that when it's used.
func needsBaseTemplate(templ string) bool {
idx := -1
inComment := false
for i := 0; i < len(templ); {
if !inComment && strings.HasPrefix(templ[i:], "{{/*") {
inComment = true
i += 4
} else if inComment && strings.HasPrefix(templ[i:], "*/}}") {
inComment = false
i += 4
} else {
r, size := utf8.DecodeRuneInString(templ[i:])
if !inComment {
if strings.HasPrefix(templ[i:], "{{") {
idx = i
break
} else if !unicode.IsSpace(r) {
break
}
}
i += size
}
}
if idx == -1 {
return false
}
return baseTemplateDefineRe.MatchString(templ[idx:])
}
func newIdentity(name string) identity.Manager {
return identity.NewManager(identity.NewPathIdentity(files.ComponentFolderLayouts, name))
}
func newStandaloneTextTemplate(funcs map[string]interface{}) tpl.TemplateParseFinder {
return &textTemplateWrapperWithLock{
RWMutex: &sync.RWMutex{},
Template: texttemplate.New("").Funcs(funcs),
}
}
func newTemplateExec(d *deps.Deps) (*templateExec, error) {
exec, funcs := newTemplateExecuter(d)
funcMap := make(map[string]interface{})
for k, v := range funcs {
funcMap[k] = v.Interface()
}
h := &templateHandler{
nameBaseTemplateName: make(map[string]string),
transformNotFound: make(map[string]*templateState),
identityNotFound: make(map[string][]identity.Manager),
shortcodes: make(map[string]*shortcodeTemplates),
templateInfo: make(map[string]tpl.Info),
baseof: make(map[string]templateInfo),
needsBaseof: make(map[string]templateInfo),
main: newTemplateNamespace(funcMap),
Deps: d,
layoutHandler: output.NewLayoutHandler(),
layoutsFs: d.BaseFs.Layouts.Fs,
layoutTemplateCache: make(map[layoutCacheKey]tpl.Template),
}
if err := h.loadEmbedded(); err != nil {
return nil, err
}
if err := h.loadTemplates(); err != nil {
return nil, err
}
e := &templateExec{
d: d,
executor: exec,
funcs: funcs,
templateHandler: h,
}
d.SetTmpl(e)
d.SetTextTmpl(newStandaloneTextTemplate(funcMap))
if d.WithTemplate != nil {
if err := d.WithTemplate(e); err != nil {
return nil, err
}
}
return e, nil
}
func newTemplateNamespace(funcs map[string]interface{}) *templateNamespace {
return &templateNamespace{
prototypeHTML: htmltemplate.New("").Funcs(funcs),
prototypeText: texttemplate.New("").Funcs(funcs),
templateStateMap: &templateStateMap{
templates: make(map[string]*templateState),
},
}
}
func newTemplateState(templ tpl.Template, info templateInfo) *templateState {
return &templateState{
info: info,
typ: info.resolveType(),
Template: templ,
Manager: newIdentity(info.name),
parseInfo: tpl.DefaultParseInfo,
}
}
type layoutCacheKey struct {
d output.LayoutDescriptor
f string
}
type templateExec struct {
d *deps.Deps
executor texttemplate.Executer
funcs map[string]reflect.Value
*templateHandler
}
func (t templateExec) Clone(d *deps.Deps) *templateExec {
exec, funcs := newTemplateExecuter(d)
t.executor = exec
t.funcs = funcs
t.d = d
return &t
}
func (t *templateExec) Execute(templ tpl.Template, wr io.Writer, data interface{}) error {
if rlocker, ok := templ.(types.RLocker); ok {
rlocker.RLock()
defer rlocker.RUnlock()
}
if t.Metrics != nil {
defer t.Metrics.MeasureSince(templ.Name(), time.Now())
}
execErr := t.executor.Execute(templ, wr, data)
if execErr != nil {
execErr = t.addFileContext(templ, execErr)
}
return execErr
}
func (t *templateExec) GetFunc(name string) (reflect.Value, bool) {
v, found := t.funcs[name]
return v, found
}
func (t *templateExec) MarkReady() error {
var err error
t.readyInit.Do(func() {
// We only need the clones if base templates are in use.
if len(t.needsBaseof) > 0 {
err = t.main.createPrototypes()
}
})
return err
}
type templateHandler struct {
main *templateNamespace
needsBaseof map[string]templateInfo
baseof map[string]templateInfo
readyInit sync.Once
// This is the filesystem to load the templates from. All the templates are
// stored in the root of this filesystem.
layoutsFs afero.Fs
layoutHandler *output.LayoutHandler
layoutTemplateCache map[layoutCacheKey]tpl.Template
layoutTemplateCacheMu sync.RWMutex
*deps.Deps
// Used to get proper filenames in errors
nameBaseTemplateName map[string]string
// Holds name and source of template definitions not found during the first
// AST transformation pass.
transformNotFound map[string]*templateState
// Holds identities of templates not found during first pass.
identityNotFound map[string][]identity.Manager
// shortcodes maps shortcode name to template variants
// (language, output format etc.) of that shortcode.
shortcodes map[string]*shortcodeTemplates
// templateInfo maps template name to some additional information about that template.
// Note that for shortcodes that same information is embedded in the
// shortcodeTemplates type.
templateInfo map[string]tpl.Info
}
// AddTemplate parses and adds a template to the collection.
// Templates with name prefixed with "_text" will be handled as plain
// text templates.
func (t *templateHandler) AddTemplate(name, tpl string) error {
templ, err := t.addTemplateTo(t.newTemplateInfo(name, tpl), t.main)
if err == nil {
t.applyTemplateTransformers(t.main, templ)
}
return err
}
func (t *templateHandler) Lookup(name string) (tpl.Template, bool) {
templ, found := t.main.Lookup(name)
if found {
return templ, true
}
return nil, false
}
func (t *templateHandler) LookupLayout(d output.LayoutDescriptor, f output.Format) (tpl.Template, bool, error) {
key := layoutCacheKey{d, f.Name}
t.layoutTemplateCacheMu.RLock()
if cacheVal, found := t.layoutTemplateCache[key]; found {
t.layoutTemplateCacheMu.RUnlock()
return cacheVal, true, nil
}
t.layoutTemplateCacheMu.RUnlock()
t.layoutTemplateCacheMu.Lock()
defer t.layoutTemplateCacheMu.Unlock()
templ, found, err := t.findLayout(d, f)
if err == nil && found {
t.layoutTemplateCache[key] = templ
return templ, true, nil
}
return nil, false, err
}
// This currently only applies to shortcodes and what we get here is the
// shortcode name.
func (t *templateHandler) LookupVariant(name string, variants tpl.TemplateVariants) (tpl.Template, bool, bool) {
name = templateBaseName(templateShortcode, name)
s, found := t.shortcodes[name]
if !found {
return nil, false, false
}
sv, found := s.fromVariants(variants)
if !found {
return nil, false, false
}
more := len(s.variants) > 1
return sv.ts, true, more
}
// LookupVariants returns all variants of name, nil if none found.
func (t *templateHandler) LookupVariants(name string) []tpl.Template {
name = templateBaseName(templateShortcode, name)
s, found := t.shortcodes[name]
if !found {
return nil
}
variants := make([]tpl.Template, len(s.variants))
for i := 0; i < len(variants); i++ {
variants[i] = s.variants[i].ts
}
return variants
}
func (t *templateHandler) HasTemplate(name string) bool {
if _, found := t.baseof[name]; found {
return true
}
if _, found := t.needsBaseof[name]; found {
return true
}
_, found := t.Lookup(name)
return found
}
func (t *templateHandler) findLayout(d output.LayoutDescriptor, f output.Format) (tpl.Template, bool, error) {
layouts, _ := t.layoutHandler.For(d, f)
for _, name := range layouts {
templ, found := t.main.Lookup(name)
if found {
return templ, true, nil
}
overlay, found := t.needsBaseof[name]
if !found {
continue
}
d.Baseof = true
baseLayouts, _ := t.layoutHandler.For(d, f)
var base templateInfo
found = false
for _, l := range baseLayouts {
base, found = t.baseof[l]
if found {
break
}
}
templ, err := t.applyBaseTemplate(overlay, base)
if err != nil {
return nil, false, err
}
ts := newTemplateState(templ, overlay)
if found {
ts.baseInfo = base
// Add the base identity to detect changes
ts.Add(identity.NewPathIdentity(files.ComponentFolderLayouts, base.name))
}
t.applyTemplateTransformers(t.main, ts)
if err := t.extractPartials(ts.Template); err != nil {
return nil, false, err
}
return ts, true, nil
}
return nil, false, nil
}
func (t *templateHandler) findTemplate(name string) *templateState {
if templ, found := t.Lookup(name); found {
return templ.(*templateState)
}
return nil
}
func (t *templateHandler) newTemplateInfo(name, tpl string) templateInfo {
var isText bool
name, isText = t.nameIsText(name)
return templateInfo{
name: name,
isText: isText,
template: tpl,
}
}
func (t *templateHandler) addFileContext(templ tpl.Template, inerr error) error {
if strings.HasPrefix(templ.Name(), "_internal") {
return inerr
}
ts, ok := templ.(*templateState)
if !ok {
return inerr
}
//lint:ignore ST1008 the error is the main result
checkFilename := func(info templateInfo, inErr error) (error, bool) {
if info.filename == "" {
return inErr, false
}
lineMatcher := func(m herrors.LineMatcher) bool {
if m.Position.LineNumber != m.LineNumber {
return false
}
identifiers := t.extractIdentifiers(m.Error.Error())
for _, id := range identifiers {
if strings.Contains(m.Line, id) {
return true
}
}
return false
}
f, err := t.layoutsFs.Open(info.filename)
if err != nil {
return inErr, false
}
defer f.Close()
fe, ok := herrors.WithFileContext(inErr, info.realFilename, f, lineMatcher)
if ok {
return fe, true
}
return inErr, false
}
inerr = errors.Wrap(inerr, "execute of template failed")
if err, ok := checkFilename(ts.info, inerr); ok {
return err
}
err, _ := checkFilename(ts.baseInfo, inerr)
return err
}
func (t *templateHandler) addShortcodeVariant(ts *templateState) {
name := ts.Name()
base := templateBaseName(templateShortcode, name)
shortcodename, variants := templateNameAndVariants(base)
templs, found := t.shortcodes[shortcodename]
if !found {
templs = &shortcodeTemplates{}
t.shortcodes[shortcodename] = templs
}
sv := shortcodeVariant{variants: variants, ts: ts}
i := templs.indexOf(variants)
if i != -1 {
// Only replace if it's an override of an internal template.
if !isInternal(name) {
templs.variants[i] = sv
}
} else {
templs.variants = append(templs.variants, sv)
}
}
func (t *templateHandler) addTemplateFile(name, path string) error {
getTemplate := func(filename string) (templateInfo, error) {
fs := t.Layouts.Fs
b, err := afero.ReadFile(fs, filename)
if err != nil {
return templateInfo{filename: filename, fs: fs}, err
}
s := removeLeadingBOM(string(b))
realFilename := filename
if fi, err := fs.Stat(filename); err == nil {
if fim, ok := fi.(hugofs.FileMetaInfo); ok {
realFilename = fim.Meta().Filename()
}
}
var isText bool
name, isText = t.nameIsText(name)
return templateInfo{
name: name,
isText: isText,
template: s,
filename: filename,
realFilename: realFilename,
fs: fs,
}, nil
}
tinfo, err := getTemplate(path)
if err != nil {
return err
}
if isBaseTemplatePath(name) {
// Store it for later.
t.baseof[name] = tinfo
return nil
}
needsBaseof := !t.noBaseNeeded(name) && needsBaseTemplate(tinfo.template)
if needsBaseof {
t.needsBaseof[name] = tinfo
return nil
}
templ, err := t.addTemplateTo(tinfo, t.main)
if err != nil {
return tinfo.errWithFileContext("parse failed", err)
}
t.applyTemplateTransformers(t.main, templ)
return nil
}
func (t *templateHandler) addTemplateTo(info templateInfo, to *templateNamespace) (*templateState, error) {
return to.parse(info)
}
func (t *templateHandler) applyBaseTemplate(overlay, base templateInfo) (tpl.Template, error) {
if overlay.isText {
var (
templ = t.main.prototypeTextClone.New(overlay.name)
err error
)
if !base.IsZero() {
templ, err = templ.Parse(base.template)
if err != nil {
return nil, base.errWithFileContext("parse failed", err)
}
}
templ, err = templ.Parse(overlay.template)
if err != nil {
return nil, overlay.errWithFileContext("parse failed", err)
}
return templ, nil
}
var (
templ = t.main.prototypeHTMLClone.New(overlay.name)
err error
)
if !base.IsZero() {
templ, err = templ.Parse(base.template)
if err != nil {
return nil, base.errWithFileContext("parse failed", err)
}
}
templ, err = htmltemplate.Must(templ.Clone()).Parse(overlay.template)
if err != nil {
return nil, overlay.errWithFileContext("parse failed", err)
}
// The extra lookup is a workaround, see
// * https://github.com/golang/go/issues/16101
// * https://github.com/gohugoio/hugo/issues/2549
templ = templ.Lookup(templ.Name())
return templ, err
}
func (t *templateHandler) applyTemplateTransformers(ns *templateNamespace, ts *templateState) (*templateContext, error) {
c, err := applyTemplateTransformers(ts, ns.newTemplateLookup(ts))
if err != nil {
return nil, err
}
for k := range c.templateNotFound {
t.transformNotFound[k] = ts
t.identityNotFound[k] = append(t.identityNotFound[k], c.t)
}
for k := range c.identityNotFound {
t.identityNotFound[k] = append(t.identityNotFound[k], c.t)
}
return c, err
}
func (t *templateHandler) extractIdentifiers(line string) []string {
m := identifiersRe.FindAllStringSubmatch(line, -1)
identifiers := make([]string, len(m))
for i := 0; i < len(m); i++ {
identifiers[i] = m[i][1]
}
return identifiers
}
func (t *templateHandler) loadEmbedded() error {
for _, kv := range embedded.EmbeddedTemplates {
name, templ := kv[0], kv[1]
if err := t.AddTemplate(internalPathPrefix+name, templ); err != nil {
return err
}
if aliases, found := embeddedTemplatesAliases[name]; found {
// TODO(bep) avoid reparsing these aliases
for _, alias := range aliases {
alias = internalPathPrefix + alias
if err := t.AddTemplate(alias, templ); err != nil {
return err
}
}
}
}
return nil
}
func (t *templateHandler) loadTemplates() error {
walker := func(path string, fi hugofs.FileMetaInfo, err error) error {
if err != nil || fi.IsDir() {
return err
}
if isDotFile(path) || isBackupFile(path) {
return nil
}
name := strings.TrimPrefix(filepath.ToSlash(path), "/")
filename := filepath.Base(path)
outputFormat, found := t.OutputFormatsConfig.FromFilename(filename)
if found && outputFormat.IsPlainText {
name = textTmplNamePrefix + name
}
if err := t.addTemplateFile(name, path); err != nil {
return err
}
return nil
}
if err := helpers.SymbolicWalk(t.Layouts.Fs, "", walker); err != nil {
if !os.IsNotExist(err) {
return err
}
return nil
}
return nil
}
func (t *templateHandler) nameIsText(name string) (string, bool) {
isText := strings.HasPrefix(name, textTmplNamePrefix)
if isText {
name = strings.TrimPrefix(name, textTmplNamePrefix)
}
return name, isText
}
func (t *templateHandler) noBaseNeeded(name string) bool {
if strings.HasPrefix(name, "shortcodes/") || strings.HasPrefix(name, "partials/") {
return true
}
return strings.Contains(name, "_markup/")
}
func (t *templateHandler) extractPartials(templ tpl.Template) error {
templs := templates(templ)
for _, templ := range templs {
if templ.Name() == "" || !strings.HasPrefix(templ.Name(), "partials/") {
continue
}
ts := newTemplateState(templ, templateInfo{name: templ.Name()})
ts.typ = templatePartial
t.main.mu.RLock()
_, found := t.main.templates[templ.Name()]
t.main.mu.RUnlock()
if !found {
t.main.mu.Lock()
// This is a template defined inline.
_, err := applyTemplateTransformers(ts, t.main.newTemplateLookup(ts))
if err != nil {
t.main.mu.Unlock()
return err
}
t.main.templates[templ.Name()] = ts
t.main.mu.Unlock()
}
}
return nil
}
func (t *templateHandler) postTransform() error {
defineCheckedHTML := false
defineCheckedText := false
for _, v := range t.main.templates {
if v.typ == templateShortcode {
t.addShortcodeVariant(v)
}
if defineCheckedHTML && defineCheckedText {
continue
}
isText := isText(v.Template)
if isText {
if defineCheckedText {
continue
}
defineCheckedText = true
} else {
if defineCheckedHTML {
continue
}
defineCheckedHTML = true
}
if err := t.extractPartials(v.Template); err != nil {
return err
}
}
for name, source := range t.transformNotFound {
lookup := t.main.newTemplateLookup(source)
templ := lookup(name)
if templ != nil {
_, err := applyTemplateTransformers(templ, lookup)
if err != nil {
return err
}
}
}
for k, v := range t.identityNotFound {
ts := t.findTemplate(k)
if ts != nil {
for _, im := range v {
im.Add(ts)
}
}
}
return nil
}
type templateNamespace struct {
prototypeText *texttemplate.Template
prototypeHTML *htmltemplate.Template
prototypeTextClone *texttemplate.Template
prototypeHTMLClone *htmltemplate.Template
*templateStateMap
}
func (t templateNamespace) Clone() *templateNamespace {
t.mu.Lock()
defer t.mu.Unlock()
t.templateStateMap = &templateStateMap{
templates: make(map[string]*templateState),
}
t.prototypeText = texttemplate.Must(t.prototypeText.Clone())
t.prototypeHTML = htmltemplate.Must(t.prototypeHTML.Clone())
return &t
}
func (t *templateNamespace) Lookup(name string) (tpl.Template, bool) {
t.mu.RLock()
defer t.mu.RUnlock()
templ, found := t.templates[name]
if !found {
return nil, false
}
return templ, found
}
func (t *templateNamespace) createPrototypes() error {
t.prototypeTextClone = texttemplate.Must(t.prototypeText.Clone())
t.prototypeHTMLClone = htmltemplate.Must(t.prototypeHTML.Clone())
return nil
}
func (t *templateNamespace) newTemplateLookup(in *templateState) func(name string) *templateState {
return func(name string) *templateState {
if templ, found := t.templates[name]; found {
if templ.isText() != in.isText() {
return nil
}
return templ
}
if templ, found := findTemplateIn(name, in); found {
return newTemplateState(templ, templateInfo{name: templ.Name()})
}
return nil
}
}
func (t *templateNamespace) parse(info templateInfo) (*templateState, error) {
t.mu.Lock()
defer t.mu.Unlock()
if info.isText {
prototype := t.prototypeText
templ, err := prototype.New(info.name).Parse(info.template)
if err != nil {
return nil, err
}
ts := newTemplateState(templ, info)
t.templates[info.name] = ts
return ts, nil
}
prototype := t.prototypeHTML
templ, err := prototype.New(info.name).Parse(info.template)
if err != nil {
return nil, err
}
ts := newTemplateState(templ, info)
t.templates[info.name] = ts
return ts, nil
}
type templateState struct {
tpl.Template
typ templateType
parseInfo tpl.ParseInfo
identity.Manager
info templateInfo
baseInfo templateInfo // Set when a base template is used.
}
func (t *templateState) ParseInfo() tpl.ParseInfo {
return t.parseInfo
}
func (t *templateState) isText() bool {
return isText(t.Template)
}
func isText(templ tpl.Template) bool {
_, isText := templ.(*texttemplate.Template)
return isText
}
type templateStateMap struct {
mu sync.RWMutex
templates map[string]*templateState
}
type templateWrapperWithLock struct {
*sync.RWMutex
tpl.Template
}
type textTemplateWrapperWithLock struct {
*sync.RWMutex
*texttemplate.Template
}
func (t *textTemplateWrapperWithLock) Lookup(name string) (tpl.Template, bool) {
t.RLock()
templ := t.Template.Lookup(name)
t.RUnlock()
if templ == nil {
return nil, false
}
return &textTemplateWrapperWithLock{
RWMutex: t.RWMutex,
Template: templ,
}, true
}
func (t *textTemplateWrapperWithLock) LookupVariant(name string, variants tpl.TemplateVariants) (tpl.Template, bool, bool) {
panic("not supported")
}
func (t *textTemplateWrapperWithLock) LookupVariants(name string) []tpl.Template {
panic("not supported")
}
func (t *textTemplateWrapperWithLock) Parse(name, tpl string) (tpl.Template, error) {
t.Lock()
defer t.Unlock()
return t.Template.New(name).Parse(tpl)
}
func isBackupFile(path string) bool {
return path[len(path)-1] == '~'
}
func isBaseTemplatePath(path string) bool {
return strings.Contains(filepath.Base(path), baseFileBase)
}
func isDotFile(path string) bool {
return filepath.Base(path)[0] == '.'
}
func removeLeadingBOM(s string) string {
const bom = '\ufeff'
for i, r := range s {
if i == 0 && r != bom {
return s
}
if i > 0 {
return s[i:]
}
}
return s
}
// resolves _internal/shortcodes/param.html => param.html etc.
func templateBaseName(typ templateType, name string) string {
name = strings.TrimPrefix(name, internalPathPrefix)
switch typ {
case templateShortcode:
return strings.TrimPrefix(name, shortcodesPathPrefix)
default:
panic("not implemented")
}
}
func unwrap(templ tpl.Template) tpl.Template {
if ts, ok := templ.(*templateState); ok {
return ts.Template
}
return templ
}
func templates(in tpl.Template) []tpl.Template {
var templs []tpl.Template
in = unwrap(in)
if textt, ok := in.(*texttemplate.Template); ok {
for _, t := range textt.Templates() {
templs = append(templs, t)
}
}
if htmlt, ok := in.(*htmltemplate.Template); ok {
for _, t := range htmlt.Templates() {
templs = append(templs, t)
}
}
return templs
}