Add Markdown render hooks for tables

Fixes #9316
Fixes #12811

markup/goldmark/internal/render/context.go

@@ -16,8 +16,12 @@ package render
 import (
 	"bytes"
 	"math/bits"
+	"sync"
+
+	htext "github.com/gohugoio/hugo/common/text"
 
 	"github.com/gohugoio/hugo/markup/converter"
+	"github.com/gohugoio/hugo/markup/converter/hooks"
 	"github.com/yuin/goldmark/ast"
 )
 
@@ -45,6 +49,7 @@ type Context struct {
 	positions []int
 	pids      []uint64
 	ordinals  map[ast.NodeKind]int
+	values    map[ast.NodeKind][]any
 }
 
 func (ctx *Context) GetAndIncrementOrdinal(kind ast.NodeKind) int {
@@ -67,6 +72,13 @@ func (ctx *Context) PopPos() int {
 	return p
 }
 
+func (ctx *Context) PopRenderedString() string {
+	pos := ctx.PopPos()
+	text := string(ctx.Bytes()[pos:])
+	ctx.Truncate(pos)
+	return text
+}
+
 // PushPid pushes a new page ID to the stack.
 func (ctx *Context) PushPid(pid uint64) {
 	ctx.pids = append(ctx.pids, pid)
@@ -91,6 +103,38 @@ func (ctx *Context) PopPid() uint64 {
 	return p
 }
 
+func (ctx *Context) PushValue(k ast.NodeKind, v any) {
+	if ctx.values == nil {
+		ctx.values = make(map[ast.NodeKind][]any)
+	}
+	ctx.values[k] = append(ctx.values[k], v)
+}
+
+func (ctx *Context) PopValue(k ast.NodeKind) any {
+	if ctx.values == nil {
+		return nil
+	}
+	v := ctx.values[k]
+	if len(v) == 0 {
+		return nil
+	}
+	i := len(v) - 1
+	r := v[i]
+	ctx.values[k] = v[:i]
+	return r
+}
+
+func (ctx *Context) PeekValue(k ast.NodeKind) any {
+	if ctx.values == nil {
+		return nil
+	}
+	v := ctx.values[k]
+	if len(v) == 0 {
+		return nil
+	}
+	return v[len(v)-1]
+}
+
 type ContextData interface {
 	RenderContext() converter.RenderContext
 	DocumentContext() converter.DocumentContext
@@ -108,3 +152,109 @@ func (ctx *RenderContextDataHolder) RenderContext() converter.RenderContext {
 func (ctx *RenderContextDataHolder) DocumentContext() converter.DocumentContext {
 	return ctx.Dctx
 }
+
+// extractSourceSample returns a sample of the source for the given node.
+// Note that this is not a copy of the source, but a slice of it,
+// so it assumes that the source is not mutated.
+func extractSourceSample(n ast.Node, src []byte) []byte {
+	var sample []byte
+
+	// Extract a source sample to use for position information.
+	if nn := n.FirstChild(); nn != nil {
+		var start, stop int
+		for i := 0; i < nn.Lines().Len() && i < 2; i++ {
+			line := nn.Lines().At(i)
+			if i == 0 {
+				start = line.Start
+			}
+			stop = line.Stop
+		}
+		// We do not mutate the source, so this is safe.
+		sample = src[start:stop]
+	}
+	return sample
+}
+
+// GetPageAndPageInner returns the current page and the inner page for the given context.
+func GetPageAndPageInner(rctx *Context) (any, any) {
+	p := rctx.DocumentContext().Document
+	pid := rctx.PeekPid()
+	if pid > 0 {
+		if lookup := rctx.DocumentContext().DocumentLookup; lookup != nil {
+			if v := rctx.DocumentContext().DocumentLookup(pid); v != nil {
+				return p, v
+			}
+		}
+	}
+	return p, p
+}
+
+// NewBaseContext creates a new BaseContext.
+func NewBaseContext(rctx *Context, renderer any, n ast.Node, src []byte, getSourceSample func() []byte, ordinal int) hooks.BaseContext {
+	if getSourceSample == nil {
+		getSourceSample = func() []byte {
+			return extractSourceSample(n, src)
+		}
+	}
+	page, pageInner := GetPageAndPageInner(rctx)
+	b := &hookBase{
+		page:      page,
+		pageInner: pageInner,
+
+		getSourceSample: getSourceSample,
+		ordinal:         ordinal,
+	}
+
+	b.createPos = func() htext.Position {
+		if resolver, ok := renderer.(hooks.ElementPositionResolver); ok {
+			return resolver.ResolvePosition(b)
+		}
+
+		return htext.Position{
+			Filename:     rctx.DocumentContext().Filename,
+			LineNumber:   1,
+			ColumnNumber: 1,
+		}
+	}
+
+	return b
+}
+
+var _ hooks.PositionerSourceTargetProvider = (*hookBase)(nil)
+
+type hookBase struct {
+	page      any
+	pageInner any
+	ordinal   int
+
+	// This is only used in error situations and is expensive to create,
+	// so delay creation until needed.
+	pos             htext.Position
+	posInit         sync.Once
+	createPos       func() htext.Position
+	getSourceSample func() []byte
+}
+
+func (c *hookBase) Page() any {
+	return c.page
+}
+
+func (c *hookBase) PageInner() any {
+	return c.pageInner
+}
+
+func (c *hookBase) Ordinal() int {
+	return c.ordinal
+}
+
+func (c *hookBase) Position() htext.Position {
+	c.posInit.Do(func() {
+		c.pos = c.createPos()
+	})
+	return c.pos
+}
+
+// For internal use.
+func (c *hookBase) PositionerSourceTarget() []byte {
+	return c.getSourceSample()
+}