gotosocial/vendor/github.com/yuin/goldmark/extension/tasklist.go

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package extension
import (
"regexp"
"github.com/yuin/goldmark"
gast "github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/extension/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"
)
var taskListRegexp = regexp.MustCompile(`^\[([\sxX])\]\s*`)
type taskCheckBoxParser struct {
}
var defaultTaskCheckBoxParser = &taskCheckBoxParser{}
// NewTaskCheckBoxParser returns a new InlineParser that can parse
// checkboxes in list items.
// This parser must take precedence over the parser.LinkParser.
func NewTaskCheckBoxParser() parser.InlineParser {
return defaultTaskCheckBoxParser
}
func (s *taskCheckBoxParser) Trigger() []byte {
return []byte{'['}
}
func (s *taskCheckBoxParser) Parse(parent gast.Node, block text.Reader, pc parser.Context) gast.Node {
// Given AST structure must be like
// - List
// - ListItem : parent.Parent
// - TextBlock : parent
// (current line)
if parent.Parent() == nil || parent.Parent().FirstChild() != parent {
return nil
}
if _, ok := parent.Parent().(*gast.ListItem); !ok {
return nil
}
line, _ := block.PeekLine()
m := taskListRegexp.FindSubmatchIndex(line)
if m == nil {
return nil
}
value := line[m[2]:m[3]][0]
block.Advance(m[1])
checked := value == 'x' || value == 'X'
return ast.NewTaskCheckBox(checked)
}
func (s *taskCheckBoxParser) CloseBlock(parent gast.Node, pc parser.Context) {
// nothing to do
}
// TaskCheckBoxHTMLRenderer is a renderer.NodeRenderer implementation that
// renders checkboxes in list items.
type TaskCheckBoxHTMLRenderer struct {
html.Config
}
// NewTaskCheckBoxHTMLRenderer returns a new TaskCheckBoxHTMLRenderer.
func NewTaskCheckBoxHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
r := &TaskCheckBoxHTMLRenderer{
Config: html.NewConfig(),
}
for _, opt := range opts {
opt.SetHTMLOption(&r.Config)
}
return r
}
// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
func (r *TaskCheckBoxHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
reg.Register(ast.KindTaskCheckBox, r.renderTaskCheckBox)
}
func (r *TaskCheckBoxHTMLRenderer) renderTaskCheckBox(
w util.BufWriter, source []byte, node gast.Node, entering bool) (gast.WalkStatus, error) {
if !entering {
return gast.WalkContinue, nil
}
n := node.(*ast.TaskCheckBox)
if n.IsChecked {
_, _ = w.WriteString(`<input checked="" disabled="" type="checkbox"`)
} else {
_, _ = w.WriteString(`<input disabled="" type="checkbox"`)
}
if r.XHTML {
_, _ = w.WriteString(" /> ")
} else {
_, _ = w.WriteString("> ")
}
return gast.WalkContinue, nil
}
type taskList struct {
}
// TaskList is an extension that allow you to use GFM task lists.
var TaskList = &taskList{}
func (e *taskList) Extend(m goldmark.Markdown) {
m.Parser().AddOptions(parser.WithInlineParsers(
util.Prioritized(NewTaskCheckBoxParser(), 0),
))
m.Renderer().AddOptions(renderer.WithNodeRenderers(
util.Prioritized(NewTaskCheckBoxHTMLRenderer(), 500),
))
}