forgejo-federation/modules/templates/htmlrenderer.go
Brecht Van Lommel 3588edbb08
Add gitea manager reload-templates command (#24843)
This can be useful to update custom templates in production mode, when
they are updated frequently and a full Gitea restart each time is
disruptive.
2023-05-22 23:51:40 +08:00

280 lines
8.2 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package templates
import (
"bufio"
"bytes"
"errors"
"fmt"
"io"
"net/http"
"path/filepath"
"regexp"
"strconv"
"strings"
"sync"
"sync/atomic"
texttemplate "text/template"
"code.gitea.io/gitea/modules/assetfs"
"code.gitea.io/gitea/modules/graceful"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/templates/scopedtmpl"
"code.gitea.io/gitea/modules/util"
)
type TemplateExecutor scopedtmpl.TemplateExecutor
type HTMLRender struct {
templates atomic.Pointer[scopedtmpl.ScopedTemplate]
}
var (
htmlRender *HTMLRender
htmlRenderOnce sync.Once
)
var ErrTemplateNotInitialized = errors.New("template system is not initialized, check your log for errors")
func (h *HTMLRender) HTML(w io.Writer, status int, name string, data interface{}) error {
if respWriter, ok := w.(http.ResponseWriter); ok {
if respWriter.Header().Get("Content-Type") == "" {
respWriter.Header().Set("Content-Type", "text/html; charset=utf-8")
}
respWriter.WriteHeader(status)
}
t, err := h.TemplateLookup(name)
if err != nil {
return texttemplate.ExecError{Name: name, Err: err}
}
return t.Execute(w, data)
}
func (h *HTMLRender) TemplateLookup(name string) (TemplateExecutor, error) {
tmpls := h.templates.Load()
if tmpls == nil {
return nil, ErrTemplateNotInitialized
}
return tmpls.Executor(name, NewFuncMap())
}
func (h *HTMLRender) CompileTemplates() error {
assets := AssetFS()
extSuffix := ".tmpl"
tmpls := scopedtmpl.NewScopedTemplate()
tmpls.Funcs(NewFuncMap())
files, err := ListWebTemplateAssetNames(assets)
if err != nil {
return nil
}
for _, file := range files {
if !strings.HasSuffix(file, extSuffix) {
continue
}
name := strings.TrimSuffix(file, extSuffix)
tmpl := tmpls.New(filepath.ToSlash(name))
buf, err := assets.ReadFile(file)
if err != nil {
return err
}
if _, err = tmpl.Parse(string(buf)); err != nil {
return err
}
}
tmpls.Freeze()
h.templates.Store(tmpls)
return nil
}
// HTMLRenderer init once and returns the globally shared html renderer
func HTMLRenderer() *HTMLRender {
htmlRenderOnce.Do(initHTMLRenderer)
return htmlRender
}
func ReloadHTMLTemplates() error {
if err := htmlRender.CompileTemplates(); err != nil {
log.Error("Template error: %v\n%s", err, log.Stack(2))
return err
}
return nil
}
func initHTMLRenderer() {
rendererType := "static"
if !setting.IsProd {
rendererType = "auto-reloading"
}
log.Debug("Creating %s HTML Renderer", rendererType)
htmlRender = &HTMLRender{}
if err := htmlRender.CompileTemplates(); err != nil {
p := &templateErrorPrettier{assets: AssetFS()}
wrapFatal(p.handleFuncNotDefinedError(err))
wrapFatal(p.handleUnexpectedOperandError(err))
wrapFatal(p.handleExpectedEndError(err))
wrapFatal(p.handleGenericTemplateError(err))
log.Fatal("HTMLRenderer CompileTemplates error: %v", err)
}
if !setting.IsProd {
go AssetFS().WatchLocalChanges(graceful.GetManager().ShutdownContext(), func() {
_ = ReloadHTMLTemplates()
})
}
}
func wrapFatal(msg string) {
if msg == "" {
return
}
log.Fatal("Unable to compile templates, %s", msg)
}
type templateErrorPrettier struct {
assets *assetfs.LayeredFS
}
var reGenericTemplateError = regexp.MustCompile(`^template: (.*):([0-9]+): (.*)`)
func (p *templateErrorPrettier) handleGenericTemplateError(err error) string {
groups := reGenericTemplateError.FindStringSubmatch(err.Error())
if len(groups) != 4 {
return ""
}
tmplName, lineStr, message := groups[1], groups[2], groups[3]
return p.makeDetailedError(message, tmplName, lineStr, -1, "")
}
var reFuncNotDefinedError = regexp.MustCompile(`^template: (.*):([0-9]+): (function "(.*)" not defined)`)
func (p *templateErrorPrettier) handleFuncNotDefinedError(err error) string {
groups := reFuncNotDefinedError.FindStringSubmatch(err.Error())
if len(groups) != 5 {
return ""
}
tmplName, lineStr, message, funcName := groups[1], groups[2], groups[3], groups[4]
funcName, _ = strconv.Unquote(`"` + funcName + `"`)
return p.makeDetailedError(message, tmplName, lineStr, -1, funcName)
}
var reUnexpectedOperandError = regexp.MustCompile(`^template: (.*):([0-9]+): (unexpected "(.*)" in operand)`)
func (p *templateErrorPrettier) handleUnexpectedOperandError(err error) string {
groups := reUnexpectedOperandError.FindStringSubmatch(err.Error())
if len(groups) != 5 {
return ""
}
tmplName, lineStr, message, unexpected := groups[1], groups[2], groups[3], groups[4]
unexpected, _ = strconv.Unquote(`"` + unexpected + `"`)
return p.makeDetailedError(message, tmplName, lineStr, -1, unexpected)
}
var reExpectedEndError = regexp.MustCompile(`^template: (.*):([0-9]+): (expected end; found (.*))`)
func (p *templateErrorPrettier) handleExpectedEndError(err error) string {
groups := reExpectedEndError.FindStringSubmatch(err.Error())
if len(groups) != 5 {
return ""
}
tmplName, lineStr, message, unexpected := groups[1], groups[2], groups[3], groups[4]
return p.makeDetailedError(message, tmplName, lineStr, -1, unexpected)
}
var (
reTemplateExecutingError = regexp.MustCompile(`^template: (.*):([1-9][0-9]*):([1-9][0-9]*): (executing .*)`)
reTemplateExecutingErrorMsg = regexp.MustCompile(`^executing "(.*)" at <(.*)>: `)
)
func (p *templateErrorPrettier) handleTemplateRenderingError(err error) string {
if groups := reTemplateExecutingError.FindStringSubmatch(err.Error()); len(groups) > 0 {
tmplName, lineStr, posStr, msgPart := groups[1], groups[2], groups[3], groups[4]
target := ""
if groups = reTemplateExecutingErrorMsg.FindStringSubmatch(msgPart); len(groups) > 0 {
target = groups[2]
}
return p.makeDetailedError(msgPart, tmplName, lineStr, posStr, target)
} else if execErr, ok := err.(texttemplate.ExecError); ok {
layerName := p.assets.GetFileLayerName(execErr.Name + ".tmpl")
return fmt.Sprintf("asset from: %s, %s", layerName, err.Error())
} else {
return err.Error()
}
}
func HandleTemplateRenderingError(err error) string {
p := &templateErrorPrettier{assets: AssetFS()}
return p.handleTemplateRenderingError(err)
}
const dashSeparator = "----------------------------------------------------------------------"
func (p *templateErrorPrettier) makeDetailedError(errMsg, tmplName string, lineNum, posNum any, target string) string {
code, layer, err := p.assets.ReadLayeredFile(tmplName + ".tmpl")
if err != nil {
return fmt.Sprintf("template error: %s, and unable to find template file %q", errMsg, tmplName)
}
line, err := util.ToInt64(lineNum)
if err != nil {
return fmt.Sprintf("template error: %s, unable to parse template %q line number %q", errMsg, tmplName, lineNum)
}
pos, err := util.ToInt64(posNum)
if err != nil {
return fmt.Sprintf("template error: %s, unable to parse template %q pos number %q", errMsg, tmplName, posNum)
}
detail := extractErrorLine(code, int(line), int(pos), target)
var msg string
if pos >= 0 {
msg = fmt.Sprintf("template error: %s:%s:%d:%d : %s", layer, tmplName, line, pos, errMsg)
} else {
msg = fmt.Sprintf("template error: %s:%s:%d : %s", layer, tmplName, line, errMsg)
}
return msg + "\n" + dashSeparator + "\n" + detail + "\n" + dashSeparator
}
func extractErrorLine(code []byte, lineNum, posNum int, target string) string {
b := bufio.NewReader(bytes.NewReader(code))
var line []byte
var err error
for i := 0; i < lineNum; i++ {
if line, err = b.ReadBytes('\n'); err != nil {
if i == lineNum-1 && errors.Is(err, io.EOF) {
err = nil
}
break
}
}
if err != nil {
return fmt.Sprintf("unable to find target line %d", lineNum)
}
line = bytes.TrimRight(line, "\r\n")
var indicatorLine []byte
targetBytes := []byte(target)
targetLen := len(targetBytes)
for i := 0; i < len(line); {
if posNum == -1 && target != "" && bytes.HasPrefix(line[i:], targetBytes) {
for j := 0; j < targetLen && i < len(line); j++ {
indicatorLine = append(indicatorLine, '^')
i++
}
} else if i == posNum {
indicatorLine = append(indicatorLine, '^')
i++
} else {
if line[i] == '\t' {
indicatorLine = append(indicatorLine, '\t')
} else {
indicatorLine = append(indicatorLine, ' ')
}
i++
}
}
// if the indicatorLine only contains spaces, trim it together
return strings.TrimRight(string(line)+"\n"+string(indicatorLine), " \t\r\n")
}