Files
oddmu/parser.go
Alex Schroeder 2188f99dea go fmt
2023-09-26 00:07:34 +02:00

105 lines
3.1 KiB
Go

package main
import (
"bytes"
"github.com/gomarkdown/markdown"
"github.com/gomarkdown/markdown/ast"
"github.com/gomarkdown/markdown/parser"
"net/url"
)
// wikiLink returns an inline parser function. This indirection is
// required because we want to call the previous definition in case
// this is not a wikiLink.
func wikiLink(p *parser.Parser, fn func(p *parser.Parser, data []byte, offset int) (int, ast.Node)) func(p *parser.Parser, data []byte, offset int) (int, ast.Node) {
return func(p *parser.Parser, original []byte, offset int) (int, ast.Node) {
data := original[offset:]
n := len(data)
// minimum: [[X]]
if n < 5 || data[1] != '[' {
return fn(p, original, offset)
}
i := 2
for i+1 < n && data[i] != ']' && data[i+1] != ']' {
i++
}
text := data[2 : i+1]
link := &ast.Link{
Destination: []byte(url.PathEscape(string(text))),
}
ast.AppendChild(link, &ast.Text{Leaf: ast.Leaf{Literal: text}})
return i + 3, link
}
}
// hashtag returns an inline parser function. This indirection is
// required because we want to receive an array of hashtags found.
func hashtag() (func(p *parser.Parser, data []byte, offset int) (int, ast.Node), *[]string) {
hashtags := make([]string, 0)
return func(p *parser.Parser, data []byte, offset int) (int, ast.Node) {
data = data[offset:]
i := 0
n := len(data)
for i < n && !parser.IsSpace(data[i]) {
i++
}
if i == 0 {
return 0, nil
}
hashtags = append(hashtags, string(data[1:i]))
link := &ast.Link{
AdditionalAttributes: []string{`class="tag"`},
Destination: append([]byte("/search?q=%23"), data[1:i]...),
Title: data[0:i],
}
text := bytes.ReplaceAll(data[0:i], []byte("_"), []byte(" "))
ast.AppendChild(link, &ast.Text{Leaf: ast.Leaf{Literal: text}})
return i, link
}, &hashtags
}
// renderHtml renders the Page.Body to HTML and sets Page.Html,
// Page.Language, Page.Hashtags, and escapes Page.Name.
func (p *Page) renderHtml() {
parser := parser.New()
prev := parser.RegisterInline('[', nil)
parser.RegisterInline('[', wikiLink(parser, prev))
fn, hashtags := hashtag()
parser.RegisterInline('#', fn)
if useWebfinger {
parser.RegisterInline('@', account)
}
maybeUnsafeHTML := markdown.ToHTML(p.Body, parser, nil)
p.Name = nameEscape(p.Name)
p.Html = sanitizeBytes(maybeUnsafeHTML)
p.Language = language(p.plainText())
p.Hashtags = *hashtags
}
// plainText renders the Page.Body to plain text and returns it,
// ignoring all the Markdown and all the newlines. The result is one
// long single line of text.
func (p *Page) plainText() string {
parser := parser.New()
doc := markdown.Parse(p.Body, parser)
text := []byte("")
ast.WalkFunc(doc, func(node ast.Node, entering bool) ast.WalkStatus {
if entering && node.AsLeaf() != nil {
text = append(text, node.AsLeaf().Literal...)
text = append(text, []byte(" ")...)
}
return ast.GoToNext
})
// Some Markdown still contains newlines
for i, c := range text {
if c == '\n' {
text[i] = ' '
}
}
// Remove trailing space
for len(text) > 0 && text[len(text)-1] == ' ' {
text = text[0 : len(text)-1]
}
return string(text)
}