hmn/src/parsing/spoilers.go

124 lines
3.6 KiB
Go

package parsing
import (
"github.com/yuin/goldmark"
gast "github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/parser"
"github.com/yuin/goldmark/renderer"
"github.com/yuin/goldmark/renderer/html"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
// ----------------------
// Parser and delimiters
// ----------------------
type spoilerParser struct{}
func NewSpoilerParser() parser.InlineParser {
return spoilerParser{}
}
func (s spoilerParser) Trigger() []byte {
return []byte{'|'}
}
func (s spoilerParser) Parse(parent gast.Node, block text.Reader, pc parser.Context) gast.Node {
before := block.PrecendingCharacter() // ScanDelimiter needs this for shady left vs. right delimiter reasons. Who delimits the delimiters?
restOfLine, segment := block.PeekLine() // Gets the rest of the line (starting at the current parser cursor index), and the segment representing the indices in the source text.
delimiter := parser.ScanDelimiter(restOfLine, before, 2, spoilerDelimiterParser{}) // Scans a consecutive run of the trigger character. Returns a delimiter node tracking which character that was, how many of it there were, etc. We do 2 here because we want ~~spoilers~~.
if delimiter == nil {
// I guess we only saw one ~ :)
return nil
}
delimiter.Segment = segment.WithStop(segment.Start + delimiter.OriginalLength) // The delimiter needs to know exactly what source indices it corresponds to.
block.Advance(delimiter.OriginalLength) // Advance the parser past the delimiter.
pc.PushDelimiter(delimiter) // Push the delimiter onto the stack (either opening or closing; both are handled the same way as far as this method is concerned).
return delimiter
}
type spoilerDelimiterParser struct{}
func (p spoilerDelimiterParser) IsDelimiter(b byte) bool {
return b == '|'
}
func (p spoilerDelimiterParser) CanOpenCloser(opener, closer *parser.Delimiter) bool {
return opener.Char == closer.Char
}
func (p spoilerDelimiterParser) OnMatch(consumes int) gast.Node {
return NewSpoiler()
}
// ----------------------
// AST node
// ----------------------
type SpoilerNode struct {
gast.BaseInline
}
var _ gast.Node = &SpoilerNode{}
func (n *SpoilerNode) Dump(source []byte, level int) {
gast.DumpHelper(n, source, level, nil, nil)
}
var KindSpoiler = gast.NewNodeKind("Spoiler")
func (n *SpoilerNode) Kind() gast.NodeKind {
return KindSpoiler
}
func NewSpoiler() gast.Node {
return &SpoilerNode{}
}
// ----------------------
// Renderer
// ----------------------
type SpoilerHTMLRenderer struct {
html.Config
}
func NewSpoilerHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
r := &SpoilerHTMLRenderer{
Config: html.NewConfig(),
}
for _, opt := range opts {
opt.SetHTMLOption(&r.Config)
}
return r
}
func (r *SpoilerHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
reg.Register(KindSpoiler, r.renderSpoiler)
}
func (r *SpoilerHTMLRenderer) renderSpoiler(w util.BufWriter, source []byte, n gast.Node, entering bool) (gast.WalkStatus, error) {
if entering {
_, _ = w.WriteString("<span class=\"spoiler\">")
} else {
_, _ = w.WriteString("</span>")
}
return gast.WalkContinue, nil
}
// ----------------------
// Extension
// ----------------------
type SpoilerExtension struct{}
func (e SpoilerExtension) Extend(m goldmark.Markdown) {
m.Parser().AddOptions(parser.WithInlineParsers(
util.Prioritized(NewSpoilerParser(), 500),
))
m.Renderer().AddOptions(renderer.WithNodeRenderers(
util.Prioritized(NewSpoilerHTMLRenderer(), 500),
))
}