forgejo/modules/templates/htmlrenderer.go
Lunny Xiao c59e1537a8
Display error log when a modified template has an error so that it could recovery when the error fixed (#22261)
A drawback is the previous generated template has been cached, so you
cannot get error in the UI but only from log

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: delvh <dev.lh@web.de>
2023-01-03 15:17:36 +08:00

255 lines
7.2 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package templates
import (
"bytes"
"context"
"fmt"
"regexp"
"strconv"
"strings"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/watcher"
"github.com/unrolled/render"
)
var (
rendererKey interface{} = "templatesHtmlRenderer"
templateError = regexp.MustCompile(`^template: (.*):([0-9]+): (.*)`)
notDefinedError = regexp.MustCompile(`^template: (.*):([0-9]+): function "(.*)" not defined`)
unexpectedError = regexp.MustCompile(`^template: (.*):([0-9]+): unexpected "(.*)" in operand`)
expectedEndError = regexp.MustCompile(`^template: (.*):([0-9]+): expected end; found (.*)`)
)
// HTMLRenderer returns the current html renderer for the context or creates and stores one within the context for future use
func HTMLRenderer(ctx context.Context) (context.Context, *render.Render) {
rendererInterface := ctx.Value(rendererKey)
if rendererInterface != nil {
renderer, ok := rendererInterface.(*render.Render)
if ok {
return ctx, renderer
}
}
rendererType := "static"
if !setting.IsProd {
rendererType = "auto-reloading"
}
log.Log(1, log.DEBUG, "Creating "+rendererType+" HTML Renderer")
compilingTemplates := true
defer func() {
if !compilingTemplates {
return
}
panicked := recover()
if panicked == nil {
return
}
// OK try to handle the panic...
err, ok := panicked.(error)
if ok {
handlePanicError(err)
}
log.Fatal("PANIC: Unable to compile templates!\n%v\n\nStacktrace:\n%s", panicked, log.Stack(2))
}()
renderer := render.New(render.Options{
Extensions: []string{".tmpl"},
Directory: "templates",
Funcs: NewFuncMap(),
Asset: GetAsset,
AssetNames: GetTemplateAssetNames,
UseMutexLock: !setting.IsProd,
IsDevelopment: false,
DisableHTTPErrorRendering: true,
})
compilingTemplates = false
if !setting.IsProd {
watcher.CreateWatcher(ctx, "HTML Templates", &watcher.CreateWatcherOpts{
PathsCallback: walkTemplateFiles,
BetweenCallback: func() {
defer func() {
if err := recover(); err != nil {
log.Error("PANIC: %v\n%s", err, log.Stack(2))
}
}()
renderer.CompileTemplates()
},
})
}
return context.WithValue(ctx, rendererKey, renderer), renderer
}
func handlePanicError(err error) {
wrapFatal(handleNotDefinedPanicError(err))
wrapFatal(handleUnexpected(err))
wrapFatal(handleExpectedEnd(err))
wrapFatal(handleGenericTemplateError(err))
}
func wrapFatal(format string, args []interface{}) {
if format == "" {
return
}
log.FatalWithSkip(1, format, args...)
}
func handleGenericTemplateError(err error) (string, []interface{}) {
groups := templateError.FindStringSubmatch(err.Error())
if len(groups) != 4 {
return "", nil
}
templateName, lineNumberStr, message := groups[1], groups[2], groups[3]
filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
if assetErr != nil {
return "", nil
}
lineNumber, _ := strconv.Atoi(lineNumberStr)
line := getLineFromAsset(templateName, lineNumber, "")
return "PANIC: Unable to compile templates!\n%s in template file %s at line %d:\n\n%s\nStacktrace:\n\n%s", []interface{}{message, filename, lineNumber, log.NewColoredValue(line, log.Reset), log.Stack(2)}
}
func handleNotDefinedPanicError(err error) (string, []interface{}) {
groups := notDefinedError.FindStringSubmatch(err.Error())
if len(groups) != 4 {
return "", nil
}
templateName, lineNumberStr, functionName := groups[1], groups[2], groups[3]
functionName, _ = strconv.Unquote(`"` + functionName + `"`)
filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
if assetErr != nil {
return "", nil
}
lineNumber, _ := strconv.Atoi(lineNumberStr)
line := getLineFromAsset(templateName, lineNumber, functionName)
return "PANIC: Unable to compile templates!\nUndefined function %q in template file %s at line %d:\n\n%s", []interface{}{functionName, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
}
func handleUnexpected(err error) (string, []interface{}) {
groups := unexpectedError.FindStringSubmatch(err.Error())
if len(groups) != 4 {
return "", nil
}
templateName, lineNumberStr, unexpected := groups[1], groups[2], groups[3]
unexpected, _ = strconv.Unquote(`"` + unexpected + `"`)
filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
if assetErr != nil {
return "", nil
}
lineNumber, _ := strconv.Atoi(lineNumberStr)
line := getLineFromAsset(templateName, lineNumber, unexpected)
return "PANIC: Unable to compile templates!\nUnexpected %q in template file %s at line %d:\n\n%s", []interface{}{unexpected, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
}
func handleExpectedEnd(err error) (string, []interface{}) {
groups := expectedEndError.FindStringSubmatch(err.Error())
if len(groups) != 4 {
return "", nil
}
templateName, lineNumberStr, unexpected := groups[1], groups[2], groups[3]
filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
if assetErr != nil {
return "", nil
}
lineNumber, _ := strconv.Atoi(lineNumberStr)
line := getLineFromAsset(templateName, lineNumber, unexpected)
return "PANIC: Unable to compile templates!\nMissing end with unexpected %q in template file %s at line %d:\n\n%s", []interface{}{unexpected, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
}
const dashSeparator = "----------------------------------------------------------------------\n"
func getLineFromAsset(templateName string, targetLineNum int, target string) string {
bs, err := GetAsset("templates/" + templateName + ".tmpl")
if err != nil {
return fmt.Sprintf("(unable to read template file: %v)", err)
}
sb := &strings.Builder{}
// Write the header
sb.WriteString(dashSeparator)
var lineBs []byte
// Iterate through the lines from the asset file to find the target line
for start, currentLineNum := 0, 1; currentLineNum <= targetLineNum && start < len(bs); currentLineNum++ {
// Find the next new line
end := bytes.IndexByte(bs[start:], '\n')
// adjust the end to be a direct pointer in to []byte
if end < 0 {
end = len(bs)
} else {
end += start
}
// set lineBs to the current line []byte
lineBs = bs[start:end]
// move start to after the current new line position
start = end + 1
// Write 2 preceding lines + the target line
if targetLineNum-currentLineNum < 3 {
_, _ = sb.Write(lineBs)
_ = sb.WriteByte('\n')
}
}
// If there is a provided target to look for in the line add a pointer to it
// e.g. ^^^^^^^
if target != "" {
idx := bytes.Index(lineBs, []byte(target))
if idx >= 0 {
// take the current line and replace preceding text with whitespace (except for tab)
for i := range lineBs[:idx] {
if lineBs[i] != '\t' {
lineBs[i] = ' '
}
}
// write the preceding "space"
_, _ = sb.Write(lineBs[:idx])
// Now write the ^^ pointer
_, _ = sb.WriteString(strings.Repeat("^", len(target)))
_ = sb.WriteByte('\n')
}
}
// Finally write the footer
sb.WriteString(dashSeparator)
return sb.String()
}