summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/mattn/godown/godown.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/mattn/godown/godown.go')
-rw-r--r--vendor/github.com/mattn/godown/godown.go372
1 files changed, 372 insertions, 0 deletions
diff --git a/vendor/github.com/mattn/godown/godown.go b/vendor/github.com/mattn/godown/godown.go
new file mode 100644
index 00000000..10423be9
--- /dev/null
+++ b/vendor/github.com/mattn/godown/godown.go
@@ -0,0 +1,372 @@
+package godown
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "regexp"
+ "strings"
+
+ "github.com/mattn/go-runewidth"
+
+ "golang.org/x/net/html"
+)
+
+func isChildOf(node *html.Node, name string) bool {
+ node = node.Parent
+ return node != nil && node.Type == html.ElementNode && strings.ToLower(node.Data) == name
+}
+
+func hasClass(node *html.Node, clazz string) bool {
+ for _, attr := range node.Attr {
+ if attr.Key == "class" {
+ for _, c := range strings.Fields(attr.Val) {
+ if c == clazz {
+ return true
+ }
+ }
+ }
+ }
+ return false
+}
+
+func attr(node *html.Node, key string) string {
+ for _, attr := range node.Attr {
+ if attr.Key == key {
+ return attr.Val
+ }
+ }
+ return ""
+}
+
+func br(node *html.Node, w io.Writer, option *Option) {
+ node = node.PrevSibling
+ if node == nil {
+ return
+ }
+ switch node.Type {
+ case html.TextNode:
+ text := strings.Trim(node.Data, " \t")
+ if text != "" && !strings.HasSuffix(text, "\n") {
+ fmt.Fprint(w, "\n")
+ }
+ case html.ElementNode:
+ switch strings.ToLower(node.Data) {
+ case "br", "p", "ul", "ol", "div", "blockquote", "h1", "h2", "h3", "h4", "h5", "h6":
+ fmt.Fprint(w, "\n")
+ }
+ }
+}
+
+func table(node *html.Node, w io.Writer, option *Option) {
+ for tr := node.FirstChild; tr != nil; tr = tr.NextSibling {
+ if tr.Type == html.ElementNode && strings.ToLower(tr.Data) == "tbody" {
+ node = tr
+ break
+ }
+ }
+ var header bool
+ var rows [][]string
+ for tr := node.FirstChild; tr != nil; tr = tr.NextSibling {
+ if tr.Type != html.ElementNode || strings.ToLower(tr.Data) != "tr" {
+ continue
+ }
+ var cols []string
+ if !header {
+ for th := tr.FirstChild; th != nil; th = th.NextSibling {
+ if th.Type != html.ElementNode || strings.ToLower(th.Data) != "th" {
+ continue
+ }
+ var buf bytes.Buffer
+ walk(th, &buf, 0, option)
+ cols = append(cols, buf.String())
+ }
+ if len(cols) > 0 {
+ rows = append(rows, cols)
+ header = true
+ continue
+ }
+ }
+ for td := tr.FirstChild; td != nil; td = td.NextSibling {
+ if td.Type != html.ElementNode || strings.ToLower(td.Data) != "td" {
+ continue
+ }
+ var buf bytes.Buffer
+ walk(td, &buf, 0, option)
+ cols = append(cols, buf.String())
+ }
+ rows = append(rows, cols)
+ }
+ maxcol := 0
+ for _, cols := range rows {
+ if len(cols) > maxcol {
+ maxcol = len(cols)
+ }
+ }
+ widths := make([]int, maxcol)
+ for _, cols := range rows {
+ for i := 0; i < maxcol; i++ {
+ if i < len(cols) {
+ width := runewidth.StringWidth(cols[i])
+ if widths[i] < width {
+ widths[i] = width
+ }
+ }
+ }
+ }
+ for i, cols := range rows {
+ for j := 0; j < maxcol; j++ {
+ fmt.Fprint(w, "|")
+ if j < len(cols) {
+ width := runewidth.StringWidth(cols[j])
+ fmt.Fprint(w, cols[j])
+ fmt.Fprint(w, strings.Repeat(" ", widths[j]-width))
+ } else {
+ fmt.Fprint(w, strings.Repeat(" ", widths[j]))
+ }
+ }
+ fmt.Fprint(w, "|\n")
+ if i == 0 && header {
+ for j := 0; j < maxcol; j++ {
+ fmt.Fprint(w, "|")
+ fmt.Fprint(w, strings.Repeat("-", widths[j]))
+ }
+ fmt.Fprint(w, "|\n")
+ }
+ }
+ fmt.Fprint(w, "\n")
+}
+
+var emptyElements = []string{
+ "area",
+ "base",
+ "br",
+ "col",
+ "embed",
+ "hr",
+ "img",
+ "input",
+ "keygen",
+ "link",
+ "meta",
+ "param",
+ "source",
+ "track",
+ "wbr",
+}
+
+func raw(node *html.Node, w io.Writer, option *Option) {
+ switch node.Type {
+ case html.ElementNode:
+ fmt.Fprintf(w, "<%s", node.Data)
+ for _, attr := range node.Attr {
+ fmt.Fprintf(w, " %s=%q", attr.Key, attr.Val)
+ }
+ found := false
+ tag := strings.ToLower(node.Data)
+ for _, e := range emptyElements {
+ if e == tag {
+ found = true
+ break
+ }
+ }
+ if found {
+ fmt.Fprint(w, "/>")
+ } else {
+ fmt.Fprint(w, ">")
+ for c := node.FirstChild; c != nil; c = c.NextSibling {
+ raw(c, w, option)
+ }
+ fmt.Fprintf(w, "</%s>", node.Data)
+ }
+ case html.TextNode:
+ fmt.Fprint(w, node.Data)
+ }
+}
+
+func bq(node *html.Node, w io.Writer, option *Option) {
+ if node.Type == html.TextNode {
+ fmt.Fprint(w, strings.Replace(node.Data, "\u00a0", " ", -1))
+ } else {
+ for c := node.FirstChild; c != nil; c = c.NextSibling {
+ bq(c, w, option)
+ }
+ }
+}
+
+func pre(node *html.Node, w io.Writer, option *Option) {
+ if node.Type == html.TextNode {
+ fmt.Fprint(w, node.Data)
+ } else {
+ for c := node.FirstChild; c != nil; c = c.NextSibling {
+ pre(c, w, option)
+ }
+ }
+}
+
+func walk(node *html.Node, w io.Writer, nest int, option *Option) {
+ if node.Type == html.TextNode {
+ if strings.TrimSpace(node.Data) != "" {
+ text := regexp.MustCompile(`[[:space:]][[:space:]]*`).ReplaceAllString(strings.Trim(node.Data, "\t\r\n"), " ")
+ fmt.Fprint(w, text)
+ }
+ }
+ n := 0
+ for c := node.FirstChild; c != nil; c = c.NextSibling {
+ switch c.Type {
+ case html.CommentNode:
+ fmt.Fprint(w, "<!--")
+ fmt.Fprint(w, c.Data)
+ fmt.Fprint(w, "-->\n")
+ case html.ElementNode:
+ switch strings.ToLower(c.Data) {
+ case "a":
+ fmt.Fprint(w, "[")
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "]("+attr(c, "href")+")")
+ case "b", "strong":
+ fmt.Fprint(w, "**")
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "**")
+ case "i", "em":
+ fmt.Fprint(w, "_")
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "_")
+ case "del":
+ fmt.Fprint(w, "~~")
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "~~")
+ case "br":
+ br(c, w, option)
+ fmt.Fprint(w, "\n\n")
+ case "p":
+ br(c, w, option)
+ walk(c, w, nest, option)
+ br(c, w, option)
+ fmt.Fprint(w, "\n\n")
+ case "code":
+ if !isChildOf(c, "pre") {
+ fmt.Fprint(w, "`")
+ pre(c, w, option)
+ fmt.Fprint(w, "`")
+ }
+ case "pre":
+ br(c, w, option)
+ var buf bytes.Buffer
+ pre(c, &buf, option)
+ var lang string
+ if option != nil && option.GuessLang != nil {
+ if guess, err := option.GuessLang(buf.String()); err == nil {
+ lang = guess
+ }
+ }
+ fmt.Fprint(w, "```"+lang+"\n")
+ fmt.Fprint(w, buf.String())
+ if !strings.HasSuffix(buf.String(), "\n") {
+ fmt.Fprint(w, "\n")
+ }
+ fmt.Fprint(w, "```\n\n")
+ case "div":
+ br(c, w, option)
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "\n")
+ case "blockquote":
+ br(c, w, option)
+ var buf bytes.Buffer
+ if hasClass(c, "code") {
+ bq(c, &buf, option)
+ var lang string
+ if option != nil && option.GuessLang != nil {
+ if guess, err := option.GuessLang(buf.String()); err == nil {
+ lang = guess
+ }
+ }
+ fmt.Fprint(w, "```"+lang+"\n")
+ fmt.Fprint(w, strings.TrimLeft(buf.String(), "\n"))
+ if !strings.HasSuffix(buf.String(), "\n") {
+ fmt.Fprint(w, "\n")
+ }
+ fmt.Fprint(w, "```\n\n")
+ } else {
+ walk(c, &buf, nest+1, option)
+
+ if lines := strings.Split(strings.TrimSpace(buf.String()), "\n"); len(lines) > 0 {
+ for _, l := range lines {
+ fmt.Fprint(w, "> "+strings.TrimSpace(l)+"\n")
+ }
+ fmt.Fprint(w, "\n")
+ }
+ }
+ case "ul", "ol":
+ br(c, w, option)
+ var buf bytes.Buffer
+ walk(c, &buf, 1, option)
+ if lines := strings.Split(strings.TrimSpace(buf.String()), "\n"); len(lines) > 0 {
+ for i, l := range lines {
+ if i > 0 || nest > 0 {
+ fmt.Fprint(w, "\n")
+ }
+ fmt.Fprint(w, strings.Repeat(" ", nest)+strings.TrimSpace(l))
+ }
+ fmt.Fprint(w, "\n")
+ }
+ case "li":
+ br(c, w, option)
+ if isChildOf(c, "ul") {
+ fmt.Fprint(w, "* ")
+ } else if isChildOf(c, "ol") {
+ n++
+ fmt.Fprint(w, fmt.Sprintf("%d. ", n))
+ }
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "\n")
+ case "h1", "h2", "h3", "h4", "h5", "h6":
+ br(c, w, option)
+ fmt.Fprint(w, strings.Repeat("#", int(rune(c.Data[1])-rune('0')))+" ")
+ walk(c, w, nest, option)
+ fmt.Fprint(w, "\n\n")
+ case "img":
+ fmt.Fprint(w, "!["+attr(c, "alt")+"]("+attr(c, "src")+")")
+ case "hr":
+ br(c, w, option)
+ fmt.Fprint(w, "\n---\n\n")
+ case "table":
+ br(c, w, option)
+ table(c, w, option)
+ case "style":
+ if option != nil && option.Style {
+ br(c, w, option)
+ raw(c, w, option)
+ fmt.Fprint(w, "\n\n")
+ }
+ case "script":
+ if option != nil && option.Script {
+ br(c, w, option)
+ raw(c, w, option)
+ fmt.Fprint(w, "\n\n")
+ }
+ default:
+ walk(c, w, nest, option)
+ }
+ default:
+ walk(c, w, nest, option)
+ }
+ }
+}
+
+type Option struct {
+ GuessLang func(string) (string, error)
+ Script bool
+ Style bool
+}
+
+// Convert convert HTML to Markdown. Read HTML from r and write to w.
+func Convert(w io.Writer, r io.Reader, option *Option) error {
+ doc, err := html.Parse(r)
+ if err != nil {
+ return err
+ }
+ walk(doc, w, 0, option)
+ fmt.Fprint(w, "\n")
+ return nil
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 12:30:26 +0000