forgejo/modules/markup/csv/csv.go

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// Copyright 2018 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"bufio"
"bytes"
"fmt"
"html"
"io"
"regexp"
"strconv"
"code.gitea.io/gitea/modules/csv"
"code.gitea.io/gitea/modules/markup"
"code.gitea.io/gitea/modules/setting"
)
func init() {
markup.RegisterRenderer(Renderer{})
}
// Renderer implements markup.Renderer for csv files
type Renderer struct{}
// Name implements markup.Renderer
func (Renderer) Name() string {
return "csv"
}
// Extensions implements markup.Renderer
func (Renderer) Extensions() []string {
return []string{".csv", ".tsv"}
}
// SanitizerRules implements markup.Renderer
func (Renderer) SanitizerRules() []setting.MarkupSanitizerRule {
return []setting.MarkupSanitizerRule{
{Element: "table", AllowAttr: "class", Regexp: regexp.MustCompile(`data-table`)},
{Element: "th", AllowAttr: "class", Regexp: regexp.MustCompile(`line-num`)},
{Element: "td", AllowAttr: "class", Regexp: regexp.MustCompile(`line-num`)},
}
}
func writeField(w io.Writer, element, class, field string) error {
if _, err := io.WriteString(w, "<"); err != nil {
return err
}
if _, err := io.WriteString(w, element); err != nil {
return err
}
if len(class) > 0 {
if _, err := io.WriteString(w, " class=\""); err != nil {
return err
}
if _, err := io.WriteString(w, class); err != nil {
return err
}
if _, err := io.WriteString(w, "\""); err != nil {
return err
}
}
if _, err := io.WriteString(w, ">"); err != nil {
return err
}
if _, err := io.WriteString(w, html.EscapeString(field)); err != nil {
return err
}
if _, err := io.WriteString(w, "</"); err != nil {
return err
}
if _, err := io.WriteString(w, element); err != nil {
return err
}
_, err := io.WriteString(w, ">")
return err
}
// Render implements markup.Renderer
func (r Renderer) Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
tmpBlock := bufio.NewWriter(output)
maxSize := setting.UI.CSV.MaxFileSize
if maxSize == 0 {
return r.tableRender(ctx, input, tmpBlock)
}
rawBytes, err := io.ReadAll(io.LimitReader(input, maxSize+1))
if err != nil {
return err
}
if int64(len(rawBytes)) <= maxSize {
return r.tableRender(ctx, bytes.NewReader(rawBytes), tmpBlock)
}
return r.fallbackRender(io.MultiReader(bytes.NewReader(rawBytes), input), tmpBlock)
}
func (Renderer) fallbackRender(input io.Reader, tmpBlock *bufio.Writer) error {
_, err := tmpBlock.WriteString("<pre>")
if err != nil {
return err
}
scan := bufio.NewScanner(input)
scan.Split(bufio.ScanRunes)
for scan.Scan() {
switch scan.Text() {
case `&`:
_, err = tmpBlock.WriteString("&amp;")
case `'`:
_, err = tmpBlock.WriteString("&#39;") // "&#39;" is shorter than "&apos;" and apos was not in HTML until HTML5.
case `<`:
_, err = tmpBlock.WriteString("&lt;")
case `>`:
_, err = tmpBlock.WriteString("&gt;")
case `"`:
_, err = tmpBlock.WriteString("&#34;") // "&#34;" is shorter than "&quot;".
default:
_, err = tmpBlock.Write(scan.Bytes())
}
if err != nil {
return err
}
}
if err = scan.Err(); err != nil {
return fmt.Errorf("fallbackRender scan: %w", err)
}
_, err = tmpBlock.WriteString("</pre>")
if err != nil {
return err
}
return tmpBlock.Flush()
}
func (Renderer) tableRender(ctx *markup.RenderContext, input io.Reader, tmpBlock *bufio.Writer) error {
rd, err := csv.CreateReaderAndDetermineDelimiter(ctx, input)
if err != nil {
return err
}
if _, err := tmpBlock.WriteString(`<table class="data-table">`); err != nil {
return err
}
row := 1
for {
fields, err := rd.Read()
if err == io.EOF {
break
}
if err != nil {
continue
}
if _, err := tmpBlock.WriteString("<tr>"); err != nil {
return err
}
element := "td"
if row == 1 {
element = "th"
}
if err := writeField(tmpBlock, element, "line-num", strconv.Itoa(row)); err != nil {
return err
}
for _, field := range fields {
if err := writeField(tmpBlock, element, "", field); err != nil {
return err
}
}
if _, err := tmpBlock.WriteString("</tr>"); err != nil {
return err
}
row++
}
if _, err = tmpBlock.WriteString("</table>"); err != nil {
return err
}
return tmpBlock.Flush()
}