package images import ( "github.com/yuin/goldmark" "github.com/yuin/goldmark/ast" "github.com/yuin/goldmark/parser" "github.com/yuin/goldmark/text" "github.com/yuin/goldmark/util" ) type ( linksExtension struct { wrapStandAloneImageWithinParagraph bool } ) const ( // Used to signal to the rendering step that an image is used in a block context. // Dont's change this; the prefix must match the internalAttrPrefix in the root goldmark package. AttrIsBlock = "_h__isBlock" ) func New(wrapStandAloneImageWithinParagraph bool) goldmark.Extender { return &linksExtension{wrapStandAloneImageWithinParagraph: wrapStandAloneImageWithinParagraph} } func (e *linksExtension) Extend(m goldmark.Markdown) { m.Parser().AddOptions( parser.WithASTTransformers( util.Prioritized(&Transformer{wrapStandAloneImageWithinParagraph: e.wrapStandAloneImageWithinParagraph}, 300), ), ) } type Transformer struct { wrapStandAloneImageWithinParagraph bool } // Transform transforms the provided Markdown AST. func (t *Transformer) Transform(doc *ast.Document, reader text.Reader, pctx parser.Context) { ast.Walk(doc, func(node ast.Node, enter bool) (ast.WalkStatus, error) { if !enter { return ast.WalkContinue, nil } if n, ok := node.(*ast.Image); ok { parent := n.Parent() if !t.wrapStandAloneImageWithinParagraph { isBlock := parent.ChildCount() == 1 if isBlock { n.SetAttributeString(AttrIsBlock, true) } if isBlock && parent.Kind() == ast.KindParagraph { for _, attr := range parent.Attributes() { // Transfer any attribute set down to the image. // Image elements does not support attributes on its own, // so it's safe to just set without checking first. n.SetAttribute(attr.Name, attr.Value) } grandParent := parent.Parent() grandParent.ReplaceChild(grandParent, parent, n) } } } return ast.WalkContinue, nil }) }