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" ) // TableCellAlignMethod indicates how are table cells aligned in HTML format.indicates how are table cells aligned in HTML format. type TableCellAlignMethod int const ( // TableCellAlignDefault renders alignments by default method. // With XHTML, alignments are rendered as an align attribute. // With HTML5, alignments are rendered as a style attribute. TableCellAlignDefault TableCellAlignMethod = iota // TableCellAlignAttribute renders alignments as an align attribute. TableCellAlignAttribute // TableCellAlignStyle renders alignments as a style attribute. TableCellAlignStyle // TableCellAlignNone does not care about alignments. // If you using classes or other styles, you can add these attributes // in an ASTTransformer. TableCellAlignNone ) // TableConfig struct holds options for the extension. type TableConfig struct { html.Config // TableCellAlignMethod indicates how are table celss aligned. TableCellAlignMethod TableCellAlignMethod } // TableOption interface is a functional option interface for the extension. type TableOption interface { renderer.Option // SetTableOption sets given option to the extension. SetTableOption(*TableConfig) } // NewTableConfig returns a new Config with defaults. func NewTableConfig() TableConfig { return TableConfig{ Config: html.NewConfig(), TableCellAlignMethod: TableCellAlignDefault, } } // SetOption implements renderer.SetOptioner. func (c *TableConfig) SetOption(name renderer.OptionName, value interface{}) { switch name { case optTableCellAlignMethod: c.TableCellAlignMethod = value.(TableCellAlignMethod) default: c.Config.SetOption(name, value) } } type withTableHTMLOptions struct { value []html.Option } func (o *withTableHTMLOptions) SetConfig(c *renderer.Config) { if o.value != nil { for _, v := range o.value { v.(renderer.Option).SetConfig(c) } } } func (o *withTableHTMLOptions) SetTableOption(c *TableConfig) { if o.value != nil { for _, v := range o.value { v.SetHTMLOption(&c.Config) } } } // WithTableHTMLOptions is functional option that wraps goldmark HTMLRenderer options. func WithTableHTMLOptions(opts ...html.Option) TableOption { return &withTableHTMLOptions{opts} } const optTableCellAlignMethod renderer.OptionName = "TableTableCellAlignMethod" type withTableCellAlignMethod struct { value TableCellAlignMethod } func (o *withTableCellAlignMethod) SetConfig(c *renderer.Config) { c.Options[optTableCellAlignMethod] = o.value } func (o *withTableCellAlignMethod) SetTableOption(c *TableConfig) { c.TableCellAlignMethod = o.value } // WithTableCellAlignMethod is a functional option that indicates how are table cells aligned in HTML format. func WithTableCellAlignMethod(a TableCellAlignMethod) TableOption { return &withTableCellAlignMethod{a} } 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 paragraphs 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 { TableConfig } // NewTableHTMLRenderer returns a new TableHTMLRenderer. func NewTableHTMLRenderer(opts ...TableOption) renderer.NodeRenderer { r := &TableHTMLRenderer{ TableConfig: NewTableConfig(), } for _, opt := range opts { opt.SetTableOption(&r.TableConfig) } 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("\n") } else { _, _ = w.WriteString("\n") } return gast.WalkContinue, nil } // TableHeaderAttributeFilter defines attribute names which 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("\n") _, _ = w.WriteString("\n") // Header has no separate handle } else { _, _ = w.WriteString("\n") _, _ = w.WriteString("\n") if n.NextSibling() != nil { _, _ = w.WriteString("\n") } } return gast.WalkContinue, nil } // TableRowAttributeFilter defines attribute names which 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("\n") } else { _, _ = w.WriteString("\n") if n.Parent().LastChild() == n { _, _ = w.WriteString("\n") } } return gast.WalkContinue, nil } // TableThCellAttributeFilter defines attribute names which table cells can have. var TableThCellAttributeFilter = html.GlobalAttributeFilter.Extend( []byte("abbr"), // [OK] Contains a short abbreviated description of the cell's content [NOT OK in ] []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 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 ) element relates to [NOT OK in ] []byte("valign"), // [Obsolete since HTML5] []byte("width"), // [Deprecated since HTML4] [Obsolete since HTML5] ) // TableTdCellAttributeFilter defines attribute names which table cells can have. var TableTdCellAttributeFilter = html.GlobalAttributeFilter.Extend( []byte("abbr"), // [Obsolete since HTML5] [OK in ] []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 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 ] []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 { fmt.Fprintf(w, "<%s", tag) if n.Alignment != ast.AlignNone { amethod := r.TableConfig.TableCellAlignMethod if amethod == TableCellAlignDefault { if r.Config.XHTML { amethod = TableCellAlignAttribute } else { amethod = TableCellAlignStyle } } switch amethod { case TableCellAlignAttribute: if _, ok := n.AttributeString("align"); !ok { // Skip align render if overridden fmt.Fprintf(w, ` align="%s"`, n.Alignment.String()) } case TableCellAlignStyle: v, ok := n.AttributeString("style") var cob util.CopyOnWriteBuffer if ok { cob = util.NewCopyOnWriteBuffer(v.([]byte)) cob.AppendByte(';') } style := fmt.Sprintf("text-align:%s", n.Alignment.String()) cob.Append(util.StringToReadOnlyBytes(style)) n.SetAttributeString("style", cob.Bytes()) } } if n.Attributes() != nil { if tag == "td" { html.RenderAttributes(w, n, TableTdCellAttributeFilter) // } else { html.RenderAttributes(w, n, TableThCellAttributeFilter) // } } _ = w.WriteByte('>') } else { fmt.Fprintf(w, "\n", tag) } return gast.WalkContinue, nil } type table struct { options []TableOption } // Table is an extension that allow you to use GFM tables . var Table = &table{ options: []TableOption{}, } // NewTable returns a new extension with given options. func NewTable(opts ...TableOption) goldmark.Extender { return &table{ options: opts, } } func (e *table) Extend(m goldmark.Markdown) { m.Parser().AddOptions(parser.WithParagraphTransformers( util.Prioritized(NewTableParagraphTransformer(), 200), )) m.Renderer().AddOptions(renderer.WithNodeRenderers( util.Prioritized(NewTableHTMLRenderer(e.options...), 500), )) }