805 lines
21 KiB
Go
805 lines
21 KiB
Go
package html
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import (
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"bytes"
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"fmt"
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"strconv"
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"github.com/yuin/goldmark/ast"
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"github.com/yuin/goldmark/renderer"
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"github.com/yuin/goldmark/util"
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)
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// A Config struct has configurations for the HTML based renderers.
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type Config struct {
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Writer Writer
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HardWraps bool
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XHTML bool
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Unsafe bool
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}
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// NewConfig returns a new Config with defaults.
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func NewConfig() Config {
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return Config{
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Writer: DefaultWriter,
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HardWraps: false,
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XHTML: false,
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Unsafe: false,
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}
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}
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// SetOption implements renderer.NodeRenderer.SetOption.
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func (c *Config) SetOption(name renderer.OptionName, value interface{}) {
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switch name {
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case optHardWraps:
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c.HardWraps = value.(bool)
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case optXHTML:
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c.XHTML = value.(bool)
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case optUnsafe:
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c.Unsafe = value.(bool)
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case optTextWriter:
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c.Writer = value.(Writer)
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}
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}
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// An Option interface sets options for HTML based renderers.
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type Option interface {
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SetHTMLOption(*Config)
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}
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// TextWriter is an option name used in WithWriter.
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const optTextWriter renderer.OptionName = "Writer"
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type withWriter struct {
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value Writer
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}
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func (o *withWriter) SetConfig(c *renderer.Config) {
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c.Options[optTextWriter] = o.value
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}
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func (o *withWriter) SetHTMLOption(c *Config) {
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c.Writer = o.value
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}
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// WithWriter is a functional option that allow you to set the given writer to
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// the renderer.
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func WithWriter(writer Writer) interface {
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renderer.Option
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Option
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} {
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return &withWriter{writer}
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}
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// HardWraps is an option name used in WithHardWraps.
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const optHardWraps renderer.OptionName = "HardWraps"
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type withHardWraps struct {
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}
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func (o *withHardWraps) SetConfig(c *renderer.Config) {
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c.Options[optHardWraps] = true
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}
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func (o *withHardWraps) SetHTMLOption(c *Config) {
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c.HardWraps = true
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}
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// WithHardWraps is a functional option that indicates whether softline breaks
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// should be rendered as '<br>'.
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func WithHardWraps() interface {
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renderer.Option
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Option
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} {
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return &withHardWraps{}
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}
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// XHTML is an option name used in WithXHTML.
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const optXHTML renderer.OptionName = "XHTML"
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type withXHTML struct {
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}
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func (o *withXHTML) SetConfig(c *renderer.Config) {
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c.Options[optXHTML] = true
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}
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func (o *withXHTML) SetHTMLOption(c *Config) {
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c.XHTML = true
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}
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// WithXHTML is a functional option indicates that nodes should be rendered in
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// xhtml instead of HTML5.
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func WithXHTML() interface {
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Option
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renderer.Option
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} {
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return &withXHTML{}
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}
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// Unsafe is an option name used in WithUnsafe.
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const optUnsafe renderer.OptionName = "Unsafe"
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type withUnsafe struct {
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}
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func (o *withUnsafe) SetConfig(c *renderer.Config) {
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c.Options[optUnsafe] = true
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}
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func (o *withUnsafe) SetHTMLOption(c *Config) {
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c.Unsafe = true
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}
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// WithUnsafe is a functional option that renders dangerous contents
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// (raw htmls and potentially dangerous links) as it is.
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func WithUnsafe() interface {
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renderer.Option
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Option
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} {
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return &withUnsafe{}
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}
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// A Renderer struct is an implementation of renderer.NodeRenderer that renders
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// nodes as (X)HTML.
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type Renderer struct {
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Config
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}
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// NewRenderer returns a new Renderer with given options.
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func NewRenderer(opts ...Option) renderer.NodeRenderer {
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r := &Renderer{
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Config: NewConfig(),
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}
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for _, opt := range opts {
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opt.SetHTMLOption(&r.Config)
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}
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return r
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}
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// RegisterFuncs implements NodeRenderer.RegisterFuncs .
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func (r *Renderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
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// blocks
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reg.Register(ast.KindDocument, r.renderDocument)
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reg.Register(ast.KindHeading, r.renderHeading)
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reg.Register(ast.KindBlockquote, r.renderBlockquote)
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reg.Register(ast.KindCodeBlock, r.renderCodeBlock)
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reg.Register(ast.KindFencedCodeBlock, r.renderFencedCodeBlock)
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reg.Register(ast.KindHTMLBlock, r.renderHTMLBlock)
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reg.Register(ast.KindList, r.renderList)
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reg.Register(ast.KindListItem, r.renderListItem)
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reg.Register(ast.KindParagraph, r.renderParagraph)
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reg.Register(ast.KindTextBlock, r.renderTextBlock)
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reg.Register(ast.KindThematicBreak, r.renderThematicBreak)
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// inlines
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reg.Register(ast.KindAutoLink, r.renderAutoLink)
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reg.Register(ast.KindCodeSpan, r.renderCodeSpan)
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reg.Register(ast.KindEmphasis, r.renderEmphasis)
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reg.Register(ast.KindImage, r.renderImage)
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reg.Register(ast.KindLink, r.renderLink)
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reg.Register(ast.KindRawHTML, r.renderRawHTML)
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reg.Register(ast.KindText, r.renderText)
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reg.Register(ast.KindString, r.renderString)
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}
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func (r *Renderer) writeLines(w util.BufWriter, source []byte, n ast.Node) {
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l := n.Lines().Len()
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for i := 0; i < l; i++ {
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line := n.Lines().At(i)
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r.Writer.RawWrite(w, line.Value(source))
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}
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}
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// GlobalAttributeFilter defines attribute names which any elements can have.
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var GlobalAttributeFilter = util.NewBytesFilter(
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[]byte("accesskey"),
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[]byte("autocapitalize"),
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[]byte("class"),
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[]byte("contenteditable"),
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[]byte("contextmenu"),
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[]byte("dir"),
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[]byte("draggable"),
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[]byte("dropzone"),
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[]byte("hidden"),
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[]byte("id"),
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[]byte("itemprop"),
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[]byte("lang"),
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[]byte("slot"),
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[]byte("spellcheck"),
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[]byte("style"),
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[]byte("tabindex"),
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[]byte("title"),
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[]byte("translate"),
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)
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func (r *Renderer) renderDocument(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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// nothing to do
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return ast.WalkContinue, nil
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}
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// HeadingAttributeFilter defines attribute names which heading elements can have
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var HeadingAttributeFilter = GlobalAttributeFilter
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func (r *Renderer) renderHeading(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.Heading)
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if entering {
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_, _ = w.WriteString("<h")
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_ = w.WriteByte("0123456"[n.Level])
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if n.Attributes() != nil {
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RenderAttributes(w, node, HeadingAttributeFilter)
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}
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("</h")
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_ = w.WriteByte("0123456"[n.Level])
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_, _ = w.WriteString(">\n")
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}
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return ast.WalkContinue, nil
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}
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// BlockquoteAttributeFilter defines attribute names which blockquote elements can have
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var BlockquoteAttributeFilter = GlobalAttributeFilter.Extend(
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[]byte("cite"),
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)
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func (r *Renderer) renderBlockquote(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if entering {
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if n.Attributes() != nil {
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_, _ = w.WriteString("<blockquote")
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RenderAttributes(w, n, BlockquoteAttributeFilter)
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("<blockquote>\n")
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}
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} else {
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_, _ = w.WriteString("</blockquote>\n")
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}
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return ast.WalkContinue, nil
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}
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func (r *Renderer) renderCodeBlock(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if entering {
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_, _ = w.WriteString("<pre><code>")
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r.writeLines(w, source, n)
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} else {
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_, _ = w.WriteString("</code></pre>\n")
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}
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return ast.WalkContinue, nil
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}
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func (r *Renderer) renderFencedCodeBlock(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.FencedCodeBlock)
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if entering {
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_, _ = w.WriteString("<pre><code")
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language := n.Language(source)
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if language != nil {
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_, _ = w.WriteString(" class=\"language-")
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r.Writer.Write(w, language)
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_, _ = w.WriteString("\"")
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}
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_ = w.WriteByte('>')
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r.writeLines(w, source, n)
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} else {
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_, _ = w.WriteString("</code></pre>\n")
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}
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return ast.WalkContinue, nil
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}
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func (r *Renderer) renderHTMLBlock(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.HTMLBlock)
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if entering {
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if r.Unsafe {
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l := n.Lines().Len()
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for i := 0; i < l; i++ {
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line := n.Lines().At(i)
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_, _ = w.Write(line.Value(source))
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}
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} else {
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_, _ = w.WriteString("<!-- raw HTML omitted -->\n")
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}
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} else {
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if n.HasClosure() {
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if r.Unsafe {
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closure := n.ClosureLine
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_, _ = w.Write(closure.Value(source))
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} else {
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_, _ = w.WriteString("<!-- raw HTML omitted -->\n")
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}
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}
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}
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return ast.WalkContinue, nil
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}
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// ListAttributeFilter defines attribute names which list elements can have.
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var ListAttributeFilter = GlobalAttributeFilter.Extend(
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[]byte("start"),
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[]byte("reversed"),
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)
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func (r *Renderer) renderList(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.List)
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tag := "ul"
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if n.IsOrdered() {
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tag = "ol"
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}
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if entering {
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_ = w.WriteByte('<')
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_, _ = w.WriteString(tag)
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if n.IsOrdered() && n.Start != 1 {
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fmt.Fprintf(w, " start=\"%d\"", n.Start)
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}
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if n.Attributes() != nil {
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RenderAttributes(w, n, ListAttributeFilter)
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}
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_, _ = w.WriteString(">\n")
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} else {
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_, _ = w.WriteString("</")
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_, _ = w.WriteString(tag)
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_, _ = w.WriteString(">\n")
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}
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return ast.WalkContinue, nil
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}
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// ListItemAttributeFilter defines attribute names which list item elements can have.
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var ListItemAttributeFilter = GlobalAttributeFilter.Extend(
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[]byte("value"),
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)
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func (r *Renderer) renderListItem(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if entering {
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if n.Attributes() != nil {
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_, _ = w.WriteString("<li")
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RenderAttributes(w, n, ListItemAttributeFilter)
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("<li>")
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}
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fc := n.FirstChild()
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if fc != nil {
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if _, ok := fc.(*ast.TextBlock); !ok {
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_ = w.WriteByte('\n')
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}
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}
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} else {
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_, _ = w.WriteString("</li>\n")
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}
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return ast.WalkContinue, nil
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}
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// ParagraphAttributeFilter defines attribute names which paragraph elements can have.
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var ParagraphAttributeFilter = GlobalAttributeFilter
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func (r *Renderer) renderParagraph(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if entering {
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if n.Attributes() != nil {
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_, _ = w.WriteString("<p")
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RenderAttributes(w, n, ParagraphAttributeFilter)
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("<p>")
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}
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} else {
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_, _ = w.WriteString("</p>\n")
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}
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return ast.WalkContinue, nil
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}
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func (r *Renderer) renderTextBlock(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if !entering {
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if _, ok := n.NextSibling().(ast.Node); ok && n.FirstChild() != nil {
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_ = w.WriteByte('\n')
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}
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}
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return ast.WalkContinue, nil
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}
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// ThematicAttributeFilter defines attribute names which hr elements can have.
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var ThematicAttributeFilter = GlobalAttributeFilter.Extend(
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[]byte("align"), // [Deprecated]
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[]byte("color"), // [Not Standardized]
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[]byte("noshade"), // [Deprecated]
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[]byte("size"), // [Deprecated]
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[]byte("width"), // [Deprecated]
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)
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func (r *Renderer) renderThematicBreak(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if !entering {
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return ast.WalkContinue, nil
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}
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_, _ = w.WriteString("<hr")
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if n.Attributes() != nil {
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RenderAttributes(w, n, ThematicAttributeFilter)
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}
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if r.XHTML {
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_, _ = w.WriteString(" />\n")
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} else {
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_, _ = w.WriteString(">\n")
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}
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return ast.WalkContinue, nil
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}
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// LinkAttributeFilter defines attribute names which link elements can have.
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var LinkAttributeFilter = GlobalAttributeFilter.Extend(
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[]byte("download"),
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// []byte("href"),
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[]byte("hreflang"),
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[]byte("media"),
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[]byte("ping"),
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[]byte("referrerpolicy"),
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[]byte("rel"),
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[]byte("shape"),
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[]byte("target"),
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)
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func (r *Renderer) renderAutoLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.AutoLink)
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if !entering {
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return ast.WalkContinue, nil
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}
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_, _ = w.WriteString(`<a href="`)
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url := n.URL(source)
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label := n.Label(source)
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if n.AutoLinkType == ast.AutoLinkEmail && !bytes.HasPrefix(bytes.ToLower(url), []byte("mailto:")) {
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_, _ = w.WriteString("mailto:")
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}
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_, _ = w.Write(util.EscapeHTML(util.URLEscape(url, false)))
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if n.Attributes() != nil {
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_ = w.WriteByte('"')
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RenderAttributes(w, n, LinkAttributeFilter)
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString(`">`)
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}
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_, _ = w.Write(util.EscapeHTML(label))
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_, _ = w.WriteString(`</a>`)
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return ast.WalkContinue, nil
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}
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// CodeAttributeFilter defines attribute names which code elements can have.
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var CodeAttributeFilter = GlobalAttributeFilter
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func (r *Renderer) renderCodeSpan(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
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if entering {
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if n.Attributes() != nil {
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_, _ = w.WriteString("<code")
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RenderAttributes(w, n, CodeAttributeFilter)
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("<code>")
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}
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for c := n.FirstChild(); c != nil; c = c.NextSibling() {
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segment := c.(*ast.Text).Segment
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value := segment.Value(source)
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if bytes.HasSuffix(value, []byte("\n")) {
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r.Writer.RawWrite(w, value[:len(value)-1])
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if c != n.LastChild() {
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r.Writer.RawWrite(w, []byte(" "))
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}
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} else {
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r.Writer.RawWrite(w, value)
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}
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}
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return ast.WalkSkipChildren, nil
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}
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_, _ = w.WriteString("</code>")
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return ast.WalkContinue, nil
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}
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// EmphasisAttributeFilter defines attribute names which emphasis elements can have.
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var EmphasisAttributeFilter = GlobalAttributeFilter
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func (r *Renderer) renderEmphasis(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.Emphasis)
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tag := "em"
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if n.Level == 2 {
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tag = "strong"
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}
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if entering {
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_ = w.WriteByte('<')
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_, _ = w.WriteString(tag)
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if n.Attributes() != nil {
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RenderAttributes(w, n, EmphasisAttributeFilter)
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}
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_ = w.WriteByte('>')
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} else {
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_, _ = w.WriteString("</")
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_, _ = w.WriteString(tag)
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_ = w.WriteByte('>')
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}
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return ast.WalkContinue, nil
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}
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func (r *Renderer) renderLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
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n := node.(*ast.Link)
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if entering {
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_, _ = w.WriteString("<a href=\"")
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if r.Unsafe || !IsDangerousURL(n.Destination) {
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_, _ = w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
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}
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_ = w.WriteByte('"')
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if n.Title != nil {
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_, _ = w.WriteString(` title="`)
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r.Writer.Write(w, n.Title)
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_ = w.WriteByte('"')
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}
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if n.Attributes() != nil {
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RenderAttributes(w, n, LinkAttributeFilter)
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}
|
|
_ = 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(n.Text(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 {
|
|
r.Writer.Write(w, segment.Value(source))
|
|
if n.HardLineBreak() || (n.SoftLineBreak() && r.HardWraps) {
|
|
if r.XHTML {
|
|
_, _ = w.WriteString("<br />\n")
|
|
} else {
|
|
_, _ = w.WriteString("<br>\n")
|
|
}
|
|
} else if n.SoftLineBreak() {
|
|
_ = 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)
|
|
}
|
|
|
|
type defaultWriter struct {
|
|
}
|
|
|
|
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) 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 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] == ';' {
|
|
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]), 0, 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 implementation of the Writer.
|
|
var DefaultWriter = &defaultWriter{}
|
|
|
|
var bDataImage = []byte("data:image/")
|
|
var bPng = []byte("png;")
|
|
var bGif = []byte("gif;")
|
|
var bJpeg = []byte("jpeg;")
|
|
var bWebp = []byte("webp;")
|
|
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) {
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
return bytes.HasPrefix(url, bJs) || bytes.HasPrefix(url, bVb) ||
|
|
bytes.HasPrefix(url, bFile) || bytes.HasPrefix(url, bData)
|
|
}
|