diff options
Diffstat (limited to 'vendor/github.com/yuin/goldmark-meta/meta.go')
| -rw-r--r-- | vendor/github.com/yuin/goldmark-meta/meta.go | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/vendor/github.com/yuin/goldmark-meta/meta.go b/vendor/github.com/yuin/goldmark-meta/meta.go new file mode 100644 index 0000000..f6c93f1 --- /dev/null +++ b/vendor/github.com/yuin/goldmark-meta/meta.go @@ -0,0 +1,320 @@ +// package meta is a extension for the goldmark(http://github.com/yuin/goldmark). +// +// This extension parses YAML metadata blocks and store metadata to a +// parser.Context. +package meta + +import ( + "bytes" + "fmt" + + "github.com/yuin/goldmark" + gast "github.com/yuin/goldmark/ast" + east "github.com/yuin/goldmark/extension/ast" + "github.com/yuin/goldmark/parser" + "github.com/yuin/goldmark/text" + "github.com/yuin/goldmark/util" + + "gopkg.in/yaml.v2" +) + +type data struct { + Map map[string]interface{} + Items yaml.MapSlice + Error error + Node gast.Node +} + +var contextKey = parser.NewContextKey() + +// Option interface sets options for this extension. +type Option interface { + metaOption() +} + +// Get returns a YAML metadata. +func Get(pc parser.Context) map[string]interface{} { + v := pc.Get(contextKey) + if v == nil { + return nil + } + d := v.(*data) + return d.Map +} + +// TryGet tries to get a YAML metadata. +// If there are YAML parsing errors, then nil and error are returned +func TryGet(pc parser.Context) (map[string]interface{}, error) { + dtmp := pc.Get(contextKey) + if dtmp == nil { + return nil, nil + } + d := dtmp.(*data) + if d.Error != nil { + return nil, d.Error + } + return d.Map, nil +} + +// GetItems returns a YAML metadata. +// GetItems preserves defined key order. +func GetItems(pc parser.Context) yaml.MapSlice { + v := pc.Get(contextKey) + if v == nil { + return nil + } + d := v.(*data) + return d.Items +} + +// TryGetItems returns a YAML metadata. +// TryGetItems preserves defined key order. +// If there are YAML parsing errors, then nil and erro are returned. +func TryGetItems(pc parser.Context) (yaml.MapSlice, error) { + dtmp := pc.Get(contextKey) + if dtmp == nil { + return nil, nil + } + d := dtmp.(*data) + if d.Error != nil { + return nil, d.Error + } + return d.Items, nil +} + +type metaParser struct { +} + +var defaultParser = &metaParser{} + +// NewParser returns a BlockParser that can parse YAML metadata blocks. +func NewParser() parser.BlockParser { + return defaultParser +} + +func isSeparator(line []byte) bool { + line = util.TrimRightSpace(util.TrimLeftSpace(line)) + for i := 0; i < len(line); i++ { + if line[i] != '-' { + return false + } + } + return true +} + +func (b *metaParser) Trigger() []byte { + return []byte{'-'} +} + +func (b *metaParser) Open(parent gast.Node, reader text.Reader, pc parser.Context) (gast.Node, parser.State) { + linenum, _ := reader.Position() + if linenum != 0 { + return nil, parser.NoChildren + } + line, _ := reader.PeekLine() + if isSeparator(line) { + return gast.NewTextBlock(), parser.NoChildren + } + return nil, parser.NoChildren +} + +func (b *metaParser) Continue(node gast.Node, reader text.Reader, pc parser.Context) parser.State { + line, segment := reader.PeekLine() + if isSeparator(line) && !util.IsBlank(line) { + reader.Advance(segment.Len()) + return parser.Close + } + node.Lines().Append(segment) + return parser.Continue | parser.NoChildren +} + +func (b *metaParser) Close(node gast.Node, reader text.Reader, pc parser.Context) { + lines := node.Lines() + var buf bytes.Buffer + for i := 0; i < lines.Len(); i++ { + segment := lines.At(i) + buf.Write(segment.Value(reader.Source())) + } + d := &data{} + d.Node = node + meta := map[string]interface{}{} + if err := yaml.Unmarshal(buf.Bytes(), &meta); err != nil { + d.Error = err + } else { + d.Map = meta + } + + metaMapSlice := yaml.MapSlice{} + if err := yaml.Unmarshal(buf.Bytes(), &metaMapSlice); err != nil { + d.Error = err + } else { + d.Items = metaMapSlice + } + + pc.Set(contextKey, d) + + if d.Error == nil { + node.Parent().RemoveChild(node.Parent(), node) + } +} + +func (b *metaParser) CanInterruptParagraph() bool { + return false +} + +func (b *metaParser) CanAcceptIndentedLine() bool { + return false +} + +type astTransformer struct { + transformerConfig +} + +type transformerConfig struct { + // Renders metadata as an html table. + Table bool + + // Stores metadata in ast.Document.Meta(). + StoresInDocument bool +} + +type transformerOption interface { + Option + + // SetMetaOption sets options for the metadata parser. + SetMetaOption(*transformerConfig) +} + +var _ transformerOption = &withTable{} + +type withTable struct { + value bool +} + +func (o *withTable) metaOption() {} + +func (o *withTable) SetMetaOption(m *transformerConfig) { + m.Table = o.value +} + +// WithTable is a functional option that renders a YAML metadata as a table. +func WithTable() Option { + return &withTable{ + value: true, + } +} + +var _ transformerOption = &withStoresInDocument{} + +type withStoresInDocument struct { + value bool +} + +func (o *withStoresInDocument) metaOption() {} + +func (o *withStoresInDocument) SetMetaOption(c *transformerConfig) { + c.StoresInDocument = o.value +} + +// WithStoresInDocument is a functional option that parser will store YAML meta in ast.Document.Meta(). +func WithStoresInDocument() Option { + return &withStoresInDocument{ + value: true, + } +} + +func newTransformer(opts ...transformerOption) parser.ASTTransformer { + p := &astTransformer{ + transformerConfig: transformerConfig{ + Table: false, + StoresInDocument: false, + }, + } + for _, o := range opts { + o.SetMetaOption(&p.transformerConfig) + } + return p +} + +func (a *astTransformer) Transform(node *gast.Document, reader text.Reader, pc parser.Context) { + dtmp := pc.Get(contextKey) + if dtmp == nil { + return + } + d := dtmp.(*data) + if d.Error != nil { + msg := gast.NewString([]byte(fmt.Sprintf("<!-- %s -->", d.Error))) + msg.SetCode(true) + d.Node.AppendChild(d.Node, msg) + return + } + + if a.Table { + meta := GetItems(pc) + if meta == nil { + return + } + table := east.NewTable() + alignments := []east.Alignment{} + for range meta { + alignments = append(alignments, east.AlignNone) + } + row := east.NewTableRow(alignments) + for _, item := range meta { + cell := east.NewTableCell() + cell.AppendChild(cell, gast.NewString([]byte(fmt.Sprintf("%v", item.Key)))) + row.AppendChild(row, cell) + } + table.AppendChild(table, east.NewTableHeader(row)) + + row = east.NewTableRow(alignments) + for _, item := range meta { + cell := east.NewTableCell() + cell.AppendChild(cell, gast.NewString([]byte(fmt.Sprintf("%v", item.Value)))) + row.AppendChild(row, cell) + } + table.AppendChild(table, row) + node.InsertBefore(node, node.FirstChild(), table) + } + + if a.StoresInDocument { + for k, v := range d.Map { + node.AddMeta(k, v) + } + } +} + +type meta struct { + options []Option +} + +// Meta is a extension for the goldmark. +var Meta = &meta{} + +// New returns a new Meta extension. +func New(opts ...Option) goldmark.Extender { + e := &meta{ + options: opts, + } + return e +} + +// Extend implements goldmark.Extender. +func (e *meta) Extend(m goldmark.Markdown) { + topts := []transformerOption{} + for _, opt := range e.options { + if topt, ok := opt.(transformerOption); ok { + topts = append(topts, topt) + } + } + m.Parser().AddOptions( + parser.WithBlockParsers( + util.Prioritized(NewParser(), 0), + ), + ) + m.Parser().AddOptions( + parser.WithASTTransformers( + util.Prioritized(newTransformer(topts...), 0), + ), + ) +} |
