forgejo/vendor/github.com/yuin/goldmark/extension/table.go
zeripath 27757714d0 Change markdown rendering from blackfriday to goldmark (#9533)
* Move to goldmark

Markdown rendering moved from blackfriday to the goldmark.

Multiple subtle changes required to the goldmark extensions to keep
current rendering and defaults.

Can go further with goldmark linkify and have this work within markdown
rendering making the link processor unnecessary.

Need to think about how to go about allowing extensions - at present it
seems that these would be hard to do without recompilation.

* linter fixes

Co-authored-by: Lauris BH <lauris@nix.lv>
2019-12-31 03:53:28 +02:00

320 lines
10 KiB
Go

package extension
import (
"bytes"
"fmt"
"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 tableDelimRegexp = regexp.MustCompile(`^[\s\-\|\:]+$`)
var tableDelimLeft = regexp.MustCompile(`^\s*\:\-+\s*$`)
var tableDelimRight = regexp.MustCompile(`^\s*\-+\:\s*$`)
var tableDelimCenter = regexp.MustCompile(`^\s*\:\-+\:\s*$`)
var tableDelimNone = regexp.MustCompile(`^\s*\-+\s*$`)
type tableParagraphTransformer struct {
}
var defaultTableParagraphTransformer = &tableParagraphTransformer{}
// NewTableParagraphTransformer returns a new ParagraphTransformer
// that can transform pargraphs into tables.
func NewTableParagraphTransformer() parser.ParagraphTransformer {
return defaultTableParagraphTransformer
}
func (b *tableParagraphTransformer) Transform(node *gast.Paragraph, reader text.Reader, pc parser.Context) {
lines := node.Lines()
if lines.Len() < 2 {
return
}
alignments := b.parseDelimiter(lines.At(1), reader)
if alignments == nil {
return
}
header := b.parseRow(lines.At(0), alignments, true, reader)
if header == nil || len(alignments) != header.ChildCount() {
return
}
table := ast.NewTable()
table.Alignments = alignments
table.AppendChild(table, ast.NewTableHeader(header))
for i := 2; i < lines.Len(); i++ {
table.AppendChild(table, b.parseRow(lines.At(i), alignments, false, reader))
}
node.Parent().InsertBefore(node.Parent(), node, table)
node.Parent().RemoveChild(node.Parent(), node)
}
func (b *tableParagraphTransformer) parseRow(segment text.Segment, alignments []ast.Alignment, isHeader bool, reader text.Reader) *ast.TableRow {
source := reader.Source()
line := segment.Value(source)
pos := 0
pos += util.TrimLeftSpaceLength(line)
limit := len(line)
limit -= util.TrimRightSpaceLength(line)
row := ast.NewTableRow(alignments)
if len(line) > 0 && line[pos] == '|' {
pos++
}
if len(line) > 0 && line[limit-1] == '|' {
limit--
}
i := 0
for ; pos < limit; i++ {
alignment := ast.AlignNone
if i >= len(alignments) {
if !isHeader {
return row
}
} else {
alignment = alignments[i]
}
closure := util.FindClosure(line[pos:], byte(0), '|', true, false)
if closure < 0 {
closure = len(line[pos:])
}
node := ast.NewTableCell()
seg := text.NewSegment(segment.Start+pos, segment.Start+pos+closure)
seg = seg.TrimLeftSpace(source)
seg = seg.TrimRightSpace(source)
node.Lines().Append(seg)
node.Alignment = alignment
row.AppendChild(row, node)
pos += closure + 1
}
for ; i < len(alignments); i++ {
row.AppendChild(row, ast.NewTableCell())
}
return row
}
func (b *tableParagraphTransformer) parseDelimiter(segment text.Segment, reader text.Reader) []ast.Alignment {
line := segment.Value(reader.Source())
if !tableDelimRegexp.Match(line) {
return nil
}
cols := bytes.Split(line, []byte{'|'})
if util.IsBlank(cols[0]) {
cols = cols[1:]
}
if len(cols) > 0 && util.IsBlank(cols[len(cols)-1]) {
cols = cols[:len(cols)-1]
}
var alignments []ast.Alignment
for _, col := range cols {
if tableDelimLeft.Match(col) {
alignments = append(alignments, ast.AlignLeft)
} else if tableDelimRight.Match(col) {
alignments = append(alignments, ast.AlignRight)
} else if tableDelimCenter.Match(col) {
alignments = append(alignments, ast.AlignCenter)
} else if tableDelimNone.Match(col) {
alignments = append(alignments, ast.AlignNone)
} else {
return nil
}
}
return alignments
}
// TableHTMLRenderer is a renderer.NodeRenderer implementation that
// renders Table nodes.
type TableHTMLRenderer struct {
html.Config
}
// NewTableHTMLRenderer returns a new TableHTMLRenderer.
func NewTableHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
r := &TableHTMLRenderer{
Config: html.NewConfig(),
}
for _, opt := range opts {
opt.SetHTMLOption(&r.Config)
}
return r
}
// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
func (r *TableHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
reg.Register(ast.KindTable, r.renderTable)
reg.Register(ast.KindTableHeader, r.renderTableHeader)
reg.Register(ast.KindTableRow, r.renderTableRow)
reg.Register(ast.KindTableCell, r.renderTableCell)
}
// TableAttributeFilter defines attribute names which table elements can have.
var TableAttributeFilter = html.GlobalAttributeFilter.Extend(
[]byte("align"), // [Deprecated]
[]byte("bgcolor"), // [Deprecated]
[]byte("border"), // [Deprecated]
[]byte("cellpadding"), // [Deprecated]
[]byte("cellspacing"), // [Deprecated]
[]byte("frame"), // [Deprecated]
[]byte("rules"), // [Deprecated]
[]byte("summary"), // [Deprecated]
[]byte("width"), // [Deprecated]
)
func (r *TableHTMLRenderer) renderTable(w util.BufWriter, source []byte, n gast.Node, entering bool) (gast.WalkStatus, error) {
if entering {
_, _ = w.WriteString("<table")
if n.Attributes() != nil {
html.RenderAttributes(w, n, TableAttributeFilter)
}
_, _ = w.WriteString(">\n")
} else {
_, _ = w.WriteString("</table>\n")
}
return gast.WalkContinue, nil
}
// TableHeaderAttributeFilter defines attribute names which <thead> elements can have.
var TableHeaderAttributeFilter = html.GlobalAttributeFilter.Extend(
[]byte("align"), // [Deprecated since HTML4] [Obsolete since HTML5]
[]byte("bgcolor"), // [Not Standardized]
[]byte("char"), // [Deprecated since HTML4] [Obsolete since HTML5]
[]byte("charoff"), // [Deprecated since HTML4] [Obsolete since HTML5]
[]byte("valign"), // [Deprecated since HTML4] [Obsolete since HTML5]
)
func (r *TableHTMLRenderer) renderTableHeader(w util.BufWriter, source []byte, n gast.Node, entering bool) (gast.WalkStatus, error) {
if entering {
_, _ = w.WriteString("<thead")
if n.Attributes() != nil {
html.RenderAttributes(w, n, TableHeaderAttributeFilter)
}
_, _ = w.WriteString(">\n")
_, _ = w.WriteString("<tr>\n") // Header <tr> has no separate handle
} else {
_, _ = w.WriteString("</tr>\n")
_, _ = w.WriteString("</thead>\n")
if n.NextSibling() != nil {
_, _ = w.WriteString("<tbody>\n")
}
}
return gast.WalkContinue, nil
}
// TableRowAttributeFilter defines attribute names which <tr> elements can have.
var TableRowAttributeFilter = html.GlobalAttributeFilter.Extend(
[]byte("align"), // [Obsolete since HTML5]
[]byte("bgcolor"), // [Obsolete since HTML5]
[]byte("char"), // [Obsolete since HTML5]
[]byte("charoff"), // [Obsolete since HTML5]
[]byte("valign"), // [Obsolete since HTML5]
)
func (r *TableHTMLRenderer) renderTableRow(w util.BufWriter, source []byte, n gast.Node, entering bool) (gast.WalkStatus, error) {
if entering {
_, _ = w.WriteString("<tr")
if n.Attributes() != nil {
html.RenderAttributes(w, n, TableRowAttributeFilter)
}
_, _ = w.WriteString(">\n")
} else {
_, _ = w.WriteString("</tr>\n")
if n.Parent().LastChild() == n {
_, _ = w.WriteString("</tbody>\n")
}
}
return gast.WalkContinue, nil
}
// TableThCellAttributeFilter defines attribute names which table <th> cells can have.
var TableThCellAttributeFilter = html.GlobalAttributeFilter.Extend(
[]byte("abbr"), // [OK] Contains a short abbreviated description of the cell's content [NOT OK in <td>]
[]byte("align"), // [Obsolete since HTML5]
[]byte("axis"), // [Obsolete since HTML5]
[]byte("bgcolor"), // [Not Standardized]
[]byte("char"), // [Obsolete since HTML5]
[]byte("charoff"), // [Obsolete since HTML5]
[]byte("colspan"), // [OK] Number of columns that the cell is to span
[]byte("headers"), // [OK] This attribute contains a list of space-separated strings, each corresponding to the id attribute of the <th> elements that apply to this element
[]byte("height"), // [Deprecated since HTML4] [Obsolete since HTML5]
[]byte("rowspan"), // [OK] Number of rows that the cell is to span
[]byte("scope"), // [OK] This enumerated attribute defines the cells that the header (defined in the <th>) element relates to [NOT OK in <td>]
[]byte("valign"), // [Obsolete since HTML5]
[]byte("width"), // [Deprecated since HTML4] [Obsolete since HTML5]
)
// TableTdCellAttributeFilter defines attribute names which table <td> cells can have.
var TableTdCellAttributeFilter = html.GlobalAttributeFilter.Extend(
[]byte("abbr"), // [Obsolete since HTML5] [OK in <th>]
[]byte("align"), // [Obsolete since HTML5]
[]byte("axis"), // [Obsolete since HTML5]
[]byte("bgcolor"), // [Not Standardized]
[]byte("char"), // [Obsolete since HTML5]
[]byte("charoff"), // [Obsolete since HTML5]
[]byte("colspan"), // [OK] Number of columns that the cell is to span
[]byte("headers"), // [OK] This attribute contains a list of space-separated strings, each corresponding to the id attribute of the <th> elements that apply to this element
[]byte("height"), // [Deprecated since HTML4] [Obsolete since HTML5]
[]byte("rowspan"), // [OK] Number of rows that the cell is to span
[]byte("scope"), // [Obsolete since HTML5] [OK in <th>]
[]byte("valign"), // [Obsolete since HTML5]
[]byte("width"), // [Deprecated since HTML4] [Obsolete since HTML5]
)
func (r *TableHTMLRenderer) renderTableCell(w util.BufWriter, source []byte, node gast.Node, entering bool) (gast.WalkStatus, error) {
n := node.(*ast.TableCell)
tag := "td"
if n.Parent().Kind() == ast.KindTableHeader {
tag = "th"
}
if entering {
align := ""
if n.Alignment != ast.AlignNone {
if _, ok := n.AttributeString("align"); !ok { // Skip align render if overridden
// TODO: "align" is deprecated. style="text-align:%s" instead?
align = fmt.Sprintf(` align="%s"`, n.Alignment.String())
}
}
fmt.Fprintf(w, "<%s", tag)
if n.Attributes() != nil {
if tag == "td" {
html.RenderAttributes(w, n, TableTdCellAttributeFilter) // <td>
} else {
html.RenderAttributes(w, n, TableThCellAttributeFilter) // <th>
}
}
fmt.Fprintf(w, "%s>", align)
} else {
fmt.Fprintf(w, "</%s>\n", tag)
}
return gast.WalkContinue, nil
}
type table struct {
}
// Table is an extension that allow you to use GFM tables .
var Table = &table{}
func (e *table) Extend(m goldmark.Markdown) {
m.Parser().AddOptions(parser.WithParagraphTransformers(
util.Prioritized(NewTableParagraphTransformer(), 200),
))
m.Renderer().AddOptions(renderer.WithNodeRenderers(
util.Prioritized(NewTableHTMLRenderer(), 500),
))
}