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-rw-r--r--vendor/github.com/yuin/goldmark/renderer/html/html.go931
1 files changed, 931 insertions, 0 deletions
diff --git a/vendor/github.com/yuin/goldmark/renderer/html/html.go b/vendor/github.com/yuin/goldmark/renderer/html/html.go
new file mode 100644
index 000000000..a3d1fe299
--- /dev/null
+++ b/vendor/github.com/yuin/goldmark/renderer/html/html.go
@@ -0,0 +1,931 @@
+package html
+
+import (
+ "bytes"
+ "fmt"
+ "strconv"
+ "unicode/utf8"
+
+ "github.com/yuin/goldmark/ast"
+ "github.com/yuin/goldmark/renderer"
+ "github.com/yuin/goldmark/util"
+)
+
+// A Config struct has configurations for the HTML based renderers.
+type Config struct {
+ Writer Writer
+ HardWraps bool
+ EastAsianLineBreaks bool
+ XHTML bool
+ Unsafe bool
+}
+
+// NewConfig returns a new Config with defaults.
+func NewConfig() Config {
+ return Config{
+ Writer: DefaultWriter,
+ HardWraps: false,
+ EastAsianLineBreaks: false,
+ XHTML: false,
+ Unsafe: false,
+ }
+}
+
+// SetOption implements renderer.NodeRenderer.SetOption.
+func (c *Config) SetOption(name renderer.OptionName, value interface{}) {
+ switch name {
+ case optHardWraps:
+ c.HardWraps = value.(bool)
+ case optEastAsianLineBreaks:
+ c.EastAsianLineBreaks = value.(bool)
+ case optXHTML:
+ c.XHTML = value.(bool)
+ case optUnsafe:
+ c.Unsafe = value.(bool)
+ case optTextWriter:
+ c.Writer = value.(Writer)
+ }
+}
+
+// An Option interface sets options for HTML based renderers.
+type Option interface {
+ SetHTMLOption(*Config)
+}
+
+// TextWriter is an option name used in WithWriter.
+const optTextWriter renderer.OptionName = "Writer"
+
+type withWriter struct {
+ value Writer
+}
+
+func (o *withWriter) SetConfig(c *renderer.Config) {
+ c.Options[optTextWriter] = o.value
+}
+
+func (o *withWriter) SetHTMLOption(c *Config) {
+ c.Writer = o.value
+}
+
+// WithWriter is a functional option that allow you to set the given writer to
+// the renderer.
+func WithWriter(writer Writer) interface {
+ renderer.Option
+ Option
+} {
+ return &withWriter{writer}
+}
+
+// HardWraps is an option name used in WithHardWraps.
+const optHardWraps renderer.OptionName = "HardWraps"
+
+type withHardWraps struct {
+}
+
+func (o *withHardWraps) SetConfig(c *renderer.Config) {
+ c.Options[optHardWraps] = true
+}
+
+func (o *withHardWraps) SetHTMLOption(c *Config) {
+ c.HardWraps = true
+}
+
+// WithHardWraps is a functional option that indicates whether softline breaks
+// should be rendered as '<br>'.
+func WithHardWraps() interface {
+ renderer.Option
+ Option
+} {
+ return &withHardWraps{}
+}
+
+// EastAsianLineBreaks is an option name used in WithEastAsianLineBreaks.
+const optEastAsianLineBreaks renderer.OptionName = "EastAsianLineBreaks"
+
+type withEastAsianLineBreaks struct {
+}
+
+func (o *withEastAsianLineBreaks) SetConfig(c *renderer.Config) {
+ c.Options[optEastAsianLineBreaks] = true
+}
+
+func (o *withEastAsianLineBreaks) SetHTMLOption(c *Config) {
+ c.EastAsianLineBreaks = true
+}
+
+// WithEastAsianLineBreaks is a functional option that indicates whether softline breaks
+// between east asian wide characters should be ignored.
+func WithEastAsianLineBreaks() interface {
+ renderer.Option
+ Option
+} {
+ return &withEastAsianLineBreaks{}
+}
+
+// XHTML is an option name used in WithXHTML.
+const optXHTML renderer.OptionName = "XHTML"
+
+type withXHTML struct {
+}
+
+func (o *withXHTML) SetConfig(c *renderer.Config) {
+ c.Options[optXHTML] = true
+}
+
+func (o *withXHTML) SetHTMLOption(c *Config) {
+ c.XHTML = true
+}
+
+// WithXHTML is a functional option indicates that nodes should be rendered in
+// xhtml instead of HTML5.
+func WithXHTML() interface {
+ Option
+ renderer.Option
+} {
+ return &withXHTML{}
+}
+
+// Unsafe is an option name used in WithUnsafe.
+const optUnsafe renderer.OptionName = "Unsafe"
+
+type withUnsafe struct {
+}
+
+func (o *withUnsafe) SetConfig(c *renderer.Config) {
+ c.Options[optUnsafe] = true
+}
+
+func (o *withUnsafe) SetHTMLOption(c *Config) {
+ c.Unsafe = true
+}
+
+// WithUnsafe is a functional option that renders dangerous contents
+// (raw htmls and potentially dangerous links) as it is.
+func WithUnsafe() interface {
+ renderer.Option
+ Option
+} {
+ return &withUnsafe{}
+}
+
+// A Renderer struct is an implementation of renderer.NodeRenderer that renders
+// nodes as (X)HTML.
+type Renderer struct {
+ Config
+}
+
+// NewRenderer returns a new Renderer with given options.
+func NewRenderer(opts ...Option) renderer.NodeRenderer {
+ r := &Renderer{
+ Config: NewConfig(),
+ }
+
+ for _, opt := range opts {
+ opt.SetHTMLOption(&r.Config)
+ }
+ return r
+}
+
+// RegisterFuncs implements NodeRenderer.RegisterFuncs .
+func (r *Renderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+ // blocks
+
+ reg.Register(ast.KindDocument, r.renderDocument)
+ reg.Register(ast.KindHeading, r.renderHeading)
+ reg.Register(ast.KindBlockquote, r.renderBlockquote)
+ reg.Register(ast.KindCodeBlock, r.renderCodeBlock)
+ reg.Register(ast.KindFencedCodeBlock, r.renderFencedCodeBlock)
+ reg.Register(ast.KindHTMLBlock, r.renderHTMLBlock)
+ reg.Register(ast.KindList, r.renderList)
+ reg.Register(ast.KindListItem, r.renderListItem)
+ reg.Register(ast.KindParagraph, r.renderParagraph)
+ reg.Register(ast.KindTextBlock, r.renderTextBlock)
+ reg.Register(ast.KindThematicBreak, r.renderThematicBreak)
+
+ // inlines
+
+ reg.Register(ast.KindAutoLink, r.renderAutoLink)
+ reg.Register(ast.KindCodeSpan, r.renderCodeSpan)
+ reg.Register(ast.KindEmphasis, r.renderEmphasis)
+ reg.Register(ast.KindImage, r.renderImage)
+ reg.Register(ast.KindLink, r.renderLink)
+ reg.Register(ast.KindRawHTML, r.renderRawHTML)
+ reg.Register(ast.KindText, r.renderText)
+ reg.Register(ast.KindString, r.renderString)
+}
+
+func (r *Renderer) writeLines(w util.BufWriter, source []byte, n ast.Node) {
+ l := n.Lines().Len()
+ for i := 0; i < l; i++ {
+ line := n.Lines().At(i)
+ r.Writer.RawWrite(w, line.Value(source))
+ }
+}
+
+// GlobalAttributeFilter defines attribute names which any elements can have.
+var GlobalAttributeFilter = util.NewBytesFilter(
+ []byte("accesskey"),
+ []byte("autocapitalize"),
+ []byte("autofocus"),
+ []byte("class"),
+ []byte("contenteditable"),
+ []byte("dir"),
+ []byte("draggable"),
+ []byte("enterkeyhint"),
+ []byte("hidden"),
+ []byte("id"),
+ []byte("inert"),
+ []byte("inputmode"),
+ []byte("is"),
+ []byte("itemid"),
+ []byte("itemprop"),
+ []byte("itemref"),
+ []byte("itemscope"),
+ []byte("itemtype"),
+ []byte("lang"),
+ []byte("part"),
+ []byte("slot"),
+ []byte("spellcheck"),
+ []byte("style"),
+ []byte("tabindex"),
+ []byte("title"),
+ []byte("translate"),
+)
+
+func (r *Renderer) renderDocument(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ // nothing to do
+ return ast.WalkContinue, nil
+}
+
+// HeadingAttributeFilter defines attribute names which heading elements can have
+var HeadingAttributeFilter = GlobalAttributeFilter
+
+func (r *Renderer) renderHeading(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.Heading)
+ if entering {
+ _, _ = w.WriteString("<h")
+ _ = w.WriteByte("0123456"[n.Level])
+ if n.Attributes() != nil {
+ RenderAttributes(w, node, HeadingAttributeFilter)
+ }
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("</h")
+ _ = w.WriteByte("0123456"[n.Level])
+ _, _ = w.WriteString(">\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+// BlockquoteAttributeFilter defines attribute names which blockquote elements can have
+var BlockquoteAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("cite"),
+)
+
+func (r *Renderer) renderBlockquote(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if entering {
+ if n.Attributes() != nil {
+ _, _ = w.WriteString("<blockquote")
+ RenderAttributes(w, n, BlockquoteAttributeFilter)
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("<blockquote>\n")
+ }
+ } else {
+ _, _ = w.WriteString("</blockquote>\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderCodeBlock(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if entering {
+ _, _ = w.WriteString("<pre><code>")
+ r.writeLines(w, source, n)
+ } else {
+ _, _ = w.WriteString("</code></pre>\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderFencedCodeBlock(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.FencedCodeBlock)
+ if entering {
+ _, _ = w.WriteString("<pre><code")
+ language := n.Language(source)
+ if language != nil {
+ _, _ = w.WriteString(" class=\"language-")
+ r.Writer.Write(w, language)
+ _, _ = w.WriteString("\"")
+ }
+ _ = w.WriteByte('>')
+ r.writeLines(w, source, n)
+ } else {
+ _, _ = w.WriteString("</code></pre>\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderHTMLBlock(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.HTMLBlock)
+ if entering {
+ if r.Unsafe {
+ l := n.Lines().Len()
+ for i := 0; i < l; i++ {
+ line := n.Lines().At(i)
+ r.Writer.SecureWrite(w, line.Value(source))
+ }
+ } else {
+ _, _ = w.WriteString("<!-- raw HTML omitted -->\n")
+ }
+ } else {
+ if n.HasClosure() {
+ if r.Unsafe {
+ closure := n.ClosureLine
+ r.Writer.SecureWrite(w, closure.Value(source))
+ } else {
+ _, _ = w.WriteString("<!-- raw HTML omitted -->\n")
+ }
+ }
+ }
+ return ast.WalkContinue, nil
+}
+
+// ListAttributeFilter defines attribute names which list elements can have.
+var ListAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("start"),
+ []byte("reversed"),
+ []byte("type"),
+)
+
+func (r *Renderer) renderList(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.List)
+ tag := "ul"
+ if n.IsOrdered() {
+ tag = "ol"
+ }
+ if entering {
+ _ = w.WriteByte('<')
+ _, _ = w.WriteString(tag)
+ if n.IsOrdered() && n.Start != 1 {
+ fmt.Fprintf(w, " start=\"%d\"", n.Start)
+ }
+ if n.Attributes() != nil {
+ RenderAttributes(w, n, ListAttributeFilter)
+ }
+ _, _ = w.WriteString(">\n")
+ } else {
+ _, _ = w.WriteString("</")
+ _, _ = w.WriteString(tag)
+ _, _ = w.WriteString(">\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+// ListItemAttributeFilter defines attribute names which list item elements can have.
+var ListItemAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("value"),
+)
+
+func (r *Renderer) renderListItem(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if entering {
+ if n.Attributes() != nil {
+ _, _ = w.WriteString("<li")
+ RenderAttributes(w, n, ListItemAttributeFilter)
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("<li>")
+ }
+ fc := n.FirstChild()
+ if fc != nil {
+ if _, ok := fc.(*ast.TextBlock); !ok {
+ _ = w.WriteByte('\n')
+ }
+ }
+ } else {
+ _, _ = w.WriteString("</li>\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+// ParagraphAttributeFilter defines attribute names which paragraph elements can have.
+var ParagraphAttributeFilter = GlobalAttributeFilter
+
+func (r *Renderer) renderParagraph(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if entering {
+ if n.Attributes() != nil {
+ _, _ = w.WriteString("<p")
+ RenderAttributes(w, n, ParagraphAttributeFilter)
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("<p>")
+ }
+ } else {
+ _, _ = w.WriteString("</p>\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderTextBlock(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ if _, ok := n.NextSibling().(ast.Node); ok && n.FirstChild() != nil {
+ _ = w.WriteByte('\n')
+ }
+ }
+ return ast.WalkContinue, nil
+}
+
+// ThematicAttributeFilter defines attribute names which hr elements can have.
+var ThematicAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("align"), // [Deprecated]
+ []byte("color"), // [Not Standardized]
+ []byte("noshade"), // [Deprecated]
+ []byte("size"), // [Deprecated]
+ []byte("width"), // [Deprecated]
+)
+
+func (r *Renderer) renderThematicBreak(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ return ast.WalkContinue, nil
+ }
+ _, _ = w.WriteString("<hr")
+ if n.Attributes() != nil {
+ RenderAttributes(w, n, ThematicAttributeFilter)
+ }
+ if r.XHTML {
+ _, _ = w.WriteString(" />\n")
+ } else {
+ _, _ = w.WriteString(">\n")
+ }
+ return ast.WalkContinue, nil
+}
+
+// LinkAttributeFilter defines attribute names which link elements can have.
+var LinkAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("download"),
+ // []byte("href"),
+ []byte("hreflang"),
+ []byte("media"),
+ []byte("ping"),
+ []byte("referrerpolicy"),
+ []byte("rel"),
+ []byte("shape"),
+ []byte("target"),
+)
+
+func (r *Renderer) renderAutoLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.AutoLink)
+ if !entering {
+ return ast.WalkContinue, nil
+ }
+ _, _ = w.WriteString(`<a href="`)
+ url := n.URL(source)
+ label := n.Label(source)
+ if n.AutoLinkType == ast.AutoLinkEmail && !bytes.HasPrefix(bytes.ToLower(url), []byte("mailto:")) {
+ _, _ = w.WriteString("mailto:")
+ }
+ _, _ = w.Write(util.EscapeHTML(util.URLEscape(url, false)))
+ if n.Attributes() != nil {
+ _ = w.WriteByte('"')
+ RenderAttributes(w, n, LinkAttributeFilter)
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString(`">`)
+ }
+ _, _ = w.Write(util.EscapeHTML(label))
+ _, _ = w.WriteString(`</a>`)
+ return ast.WalkContinue, nil
+}
+
+// CodeAttributeFilter defines attribute names which code elements can have.
+var CodeAttributeFilter = GlobalAttributeFilter
+
+func (r *Renderer) renderCodeSpan(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
+ if entering {
+ if n.Attributes() != nil {
+ _, _ = w.WriteString("<code")
+ RenderAttributes(w, n, CodeAttributeFilter)
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("<code>")
+ }
+ for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+ segment := c.(*ast.Text).Segment
+ value := segment.Value(source)
+ if bytes.HasSuffix(value, []byte("\n")) {
+ r.Writer.RawWrite(w, value[:len(value)-1])
+ r.Writer.RawWrite(w, []byte(" "))
+ } else {
+ r.Writer.RawWrite(w, value)
+ }
+ }
+ return ast.WalkSkipChildren, nil
+ }
+ _, _ = w.WriteString("</code>")
+ return ast.WalkContinue, nil
+}
+
+// EmphasisAttributeFilter defines attribute names which emphasis elements can have.
+var EmphasisAttributeFilter = GlobalAttributeFilter
+
+func (r *Renderer) renderEmphasis(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.Emphasis)
+ tag := "em"
+ if n.Level == 2 {
+ tag = "strong"
+ }
+ if entering {
+ _ = w.WriteByte('<')
+ _, _ = w.WriteString(tag)
+ if n.Attributes() != nil {
+ RenderAttributes(w, n, EmphasisAttributeFilter)
+ }
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("</")
+ _, _ = w.WriteString(tag)
+ _ = w.WriteByte('>')
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ n := node.(*ast.Link)
+ if entering {
+ _, _ = w.WriteString("<a href=\"")
+ if r.Unsafe || !IsDangerousURL(n.Destination) {
+ _, _ = w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
+ }
+ _ = w.WriteByte('"')
+ if n.Title != nil {
+ _, _ = w.WriteString(` title="`)
+ r.Writer.Write(w, n.Title)
+ _ = w.WriteByte('"')
+ }
+ if n.Attributes() != nil {
+ RenderAttributes(w, n, LinkAttributeFilter)
+ }
+ _ = w.WriteByte('>')
+ } else {
+ _, _ = w.WriteString("</a>")
+ }
+ return ast.WalkContinue, nil
+}
+
+// ImageAttributeFilter defines attribute names which image elements can have.
+var ImageAttributeFilter = GlobalAttributeFilter.Extend(
+ []byte("align"),
+ []byte("border"),
+ []byte("crossorigin"),
+ []byte("decoding"),
+ []byte("height"),
+ []byte("importance"),
+ []byte("intrinsicsize"),
+ []byte("ismap"),
+ []byte("loading"),
+ []byte("referrerpolicy"),
+ []byte("sizes"),
+ []byte("srcset"),
+ []byte("usemap"),
+ []byte("width"),
+)
+
+func (r *Renderer) renderImage(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ return ast.WalkContinue, nil
+ }
+ n := node.(*ast.Image)
+ _, _ = w.WriteString("<img src=\"")
+ if r.Unsafe || !IsDangerousURL(n.Destination) {
+ _, _ = w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
+ }
+ _, _ = w.WriteString(`" alt="`)
+ _, _ = w.Write(nodeToHTMLText(n, source))
+ _ = w.WriteByte('"')
+ if n.Title != nil {
+ _, _ = w.WriteString(` title="`)
+ r.Writer.Write(w, n.Title)
+ _ = w.WriteByte('"')
+ }
+ if n.Attributes() != nil {
+ RenderAttributes(w, n, ImageAttributeFilter)
+ }
+ if r.XHTML {
+ _, _ = w.WriteString(" />")
+ } else {
+ _, _ = w.WriteString(">")
+ }
+ return ast.WalkSkipChildren, nil
+}
+
+func (r *Renderer) renderRawHTML(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ return ast.WalkSkipChildren, nil
+ }
+ if r.Unsafe {
+ n := node.(*ast.RawHTML)
+ l := n.Segments.Len()
+ for i := 0; i < l; i++ {
+ segment := n.Segments.At(i)
+ _, _ = w.Write(segment.Value(source))
+ }
+ return ast.WalkSkipChildren, nil
+ }
+ _, _ = w.WriteString("<!-- raw HTML omitted -->")
+ return ast.WalkSkipChildren, nil
+}
+
+func (r *Renderer) renderText(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ return ast.WalkContinue, nil
+ }
+ n := node.(*ast.Text)
+ segment := n.Segment
+ if n.IsRaw() {
+ r.Writer.RawWrite(w, segment.Value(source))
+ } else {
+ value := segment.Value(source)
+ r.Writer.Write(w, value)
+ if n.HardLineBreak() || (n.SoftLineBreak() && r.HardWraps) {
+ if r.XHTML {
+ _, _ = w.WriteString("<br />\n")
+ } else {
+ _, _ = w.WriteString("<br>\n")
+ }
+ } else if n.SoftLineBreak() {
+ if r.EastAsianLineBreaks && len(value) != 0 {
+ sibling := node.NextSibling()
+ if sibling != nil && sibling.Kind() == ast.KindText {
+ if siblingText := sibling.(*ast.Text).Text(source); len(siblingText) != 0 {
+ thisLastRune := util.ToRune(value, len(value)-1)
+ siblingFirstRune, _ := utf8.DecodeRune(siblingText)
+ if !(util.IsEastAsianWideRune(thisLastRune) &&
+ util.IsEastAsianWideRune(siblingFirstRune)) {
+ _ = w.WriteByte('\n')
+ }
+ }
+ }
+ } else {
+ _ = w.WriteByte('\n')
+ }
+ }
+ }
+ return ast.WalkContinue, nil
+}
+
+func (r *Renderer) renderString(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+ if !entering {
+ return ast.WalkContinue, nil
+ }
+ n := node.(*ast.String)
+ if n.IsCode() {
+ _, _ = w.Write(n.Value)
+ } else {
+ if n.IsRaw() {
+ r.Writer.RawWrite(w, n.Value)
+ } else {
+ r.Writer.Write(w, n.Value)
+ }
+ }
+ return ast.WalkContinue, nil
+}
+
+var dataPrefix = []byte("data-")
+
+// RenderAttributes renders given node's attributes.
+// You can specify attribute names to render by the filter.
+// If filter is nil, RenderAttributes renders all attributes.
+func RenderAttributes(w util.BufWriter, node ast.Node, filter util.BytesFilter) {
+ for _, attr := range node.Attributes() {
+ if filter != nil && !filter.Contains(attr.Name) {
+ if !bytes.HasPrefix(attr.Name, dataPrefix) {
+ continue
+ }
+ }
+ _, _ = w.WriteString(" ")
+ _, _ = w.Write(attr.Name)
+ _, _ = w.WriteString(`="`)
+ // TODO: convert numeric values to strings
+ _, _ = w.Write(util.EscapeHTML(attr.Value.([]byte)))
+ _ = w.WriteByte('"')
+ }
+}
+
+// A Writer interface writes textual contents to a writer.
+type Writer interface {
+ // Write writes the given source to writer with resolving references and unescaping
+ // backslash escaped characters.
+ Write(writer util.BufWriter, source []byte)
+
+ // RawWrite writes the given source to writer without resolving references and
+ // unescaping backslash escaped characters.
+ RawWrite(writer util.BufWriter, source []byte)
+
+ // SecureWrite writes the given source to writer with replacing insecure characters.
+ SecureWrite(writer util.BufWriter, source []byte)
+}
+
+var replacementCharacter = []byte("\ufffd")
+
+// A WriterConfig struct has configurations for the HTML based writers.
+type WriterConfig struct {
+ // EscapedSpace is an option that indicates that a '\' escaped half-space(0x20) should not be rendered.
+ EscapedSpace bool
+}
+
+// A WriterOption interface sets options for HTML based writers.
+type WriterOption func(*WriterConfig)
+
+// WithEscapedSpace is a WriterOption indicates that a '\' escaped half-space(0x20) should not be rendered.
+func WithEscapedSpace() WriterOption {
+ return func(c *WriterConfig) {
+ c.EscapedSpace = true
+ }
+}
+
+type defaultWriter struct {
+ WriterConfig
+}
+
+// NewWriter returns a new Writer.
+func NewWriter(opts ...WriterOption) Writer {
+ w := &defaultWriter{}
+ for _, opt := range opts {
+ opt(&w.WriterConfig)
+ }
+ return w
+}
+
+func escapeRune(writer util.BufWriter, r rune) {
+ if r < 256 {
+ v := util.EscapeHTMLByte(byte(r))
+ if v != nil {
+ _, _ = writer.Write(v)
+ return
+ }
+ }
+ _, _ = writer.WriteRune(util.ToValidRune(r))
+}
+
+func (d *defaultWriter) SecureWrite(writer util.BufWriter, source []byte) {
+ n := 0
+ l := len(source)
+ for i := 0; i < l; i++ {
+ if source[i] == '\u0000' {
+ _, _ = writer.Write(source[i-n : i])
+ n = 0
+ _, _ = writer.Write(replacementCharacter)
+ continue
+ }
+ n++
+ }
+ if n != 0 {
+ _, _ = writer.Write(source[l-n:])
+ }
+}
+
+func (d *defaultWriter) RawWrite(writer util.BufWriter, source []byte) {
+ n := 0
+ l := len(source)
+ for i := 0; i < l; i++ {
+ v := util.EscapeHTMLByte(source[i])
+ if v != nil {
+ _, _ = writer.Write(source[i-n : i])
+ n = 0
+ _, _ = writer.Write(v)
+ continue
+ }
+ n++
+ }
+ if n != 0 {
+ _, _ = writer.Write(source[l-n:])
+ }
+}
+
+func (d *defaultWriter) Write(writer util.BufWriter, source []byte) {
+ escaped := false
+ var ok bool
+ limit := len(source)
+ n := 0
+ for i := 0; i < limit; i++ {
+ c := source[i]
+ if escaped {
+ if util.IsPunct(c) {
+ d.RawWrite(writer, source[n:i-1])
+ n = i
+ escaped = false
+ continue
+ }
+ if d.EscapedSpace && c == ' ' {
+ d.RawWrite(writer, source[n:i-1])
+ n = i + 1
+ escaped = false
+ continue
+ }
+ }
+ if c == '\x00' {
+ d.RawWrite(writer, source[n:i])
+ d.RawWrite(writer, replacementCharacter)
+ n = i + 1
+ escaped = false
+ continue
+ }
+ if c == '&' {
+ pos := i
+ next := i + 1
+ if next < limit && source[next] == '#' {
+ nnext := next + 1
+ if nnext < limit {
+ nc := source[nnext]
+ // code point like #x22;
+ if nnext < limit && nc == 'x' || nc == 'X' {
+ start := nnext + 1
+ i, ok = util.ReadWhile(source, [2]int{start, limit}, util.IsHexDecimal)
+ if ok && i < limit && source[i] == ';' && i-start < 7 {
+ v, _ := strconv.ParseUint(util.BytesToReadOnlyString(source[start:i]), 16, 32)
+ d.RawWrite(writer, source[n:pos])
+ n = i + 1
+ escapeRune(writer, rune(v))
+ continue
+ }
+ // code point like #1234;
+ } else if nc >= '0' && nc <= '9' {
+ start := nnext
+ i, ok = util.ReadWhile(source, [2]int{start, limit}, util.IsNumeric)
+ if ok && i < limit && i-start < 8 && source[i] == ';' {
+ v, _ := strconv.ParseUint(util.BytesToReadOnlyString(source[start:i]), 10, 32)
+ d.RawWrite(writer, source[n:pos])
+ n = i + 1
+ escapeRune(writer, rune(v))
+ continue
+ }
+ }
+ }
+ } else {
+ start := next
+ i, ok = util.ReadWhile(source, [2]int{start, limit}, util.IsAlphaNumeric)
+ // entity reference
+ if ok && i < limit && source[i] == ';' {
+ name := util.BytesToReadOnlyString(source[start:i])
+ entity, ok := util.LookUpHTML5EntityByName(name)
+ if ok {
+ d.RawWrite(writer, source[n:pos])
+ n = i + 1
+ d.RawWrite(writer, entity.Characters)
+ continue
+ }
+ }
+ }
+ i = next - 1
+ }
+ if c == '\\' {
+ escaped = true
+ continue
+ }
+ escaped = false
+ }
+ d.RawWrite(writer, source[n:])
+}
+
+// DefaultWriter is a default instance of the Writer.
+var DefaultWriter = NewWriter()
+
+var bDataImage = []byte("data:image/")
+var bPng = []byte("png;")
+var bGif = []byte("gif;")
+var bJpeg = []byte("jpeg;")
+var bWebp = []byte("webp;")
+var bSvg = []byte("svg+xml;")
+var bJs = []byte("javascript:")
+var bVb = []byte("vbscript:")
+var bFile = []byte("file:")
+var bData = []byte("data:")
+
+// IsDangerousURL returns true if the given url seems a potentially dangerous url,
+// otherwise false.
+func IsDangerousURL(url []byte) bool {
+ if bytes.HasPrefix(url, bDataImage) && len(url) >= 11 {
+ v := url[11:]
+ if bytes.HasPrefix(v, bPng) || bytes.HasPrefix(v, bGif) ||
+ bytes.HasPrefix(v, bJpeg) || bytes.HasPrefix(v, bWebp) ||
+ bytes.HasPrefix(v, bSvg) {
+ return false
+ }
+ return true
+ }
+ return bytes.HasPrefix(url, bJs) || bytes.HasPrefix(url, bVb) ||
+ bytes.HasPrefix(url, bFile) || bytes.HasPrefix(url, bData)
+}
+
+func nodeToHTMLText(n ast.Node, source []byte) []byte {
+ var buf bytes.Buffer
+ for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+ if s, ok := c.(*ast.String); ok && s.IsCode() {
+ buf.Write(s.Text(source))
+ } else if !c.HasChildren() {
+ buf.Write(util.EscapeHTML(c.Text(source)))
+ } else {
+ buf.Write(nodeToHTMLText(c, source))
+ }
+ }
+ return buf.Bytes()
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-04 07:03:26 +0000