V2 editable blocks need structure-preserving DOM reconciliation for mixed-inline editing

What happened

EditableBlocks started as an honest public surface for narrow text-block proofs.

The next expansion was mixed-inline editing:

• direct text children
• inline element children
• selection, typing, and clipboard behavior through that shape

The first red showed the root problem fast:

• typing inside an inline child could preserve visible text
• but the old Editable DOM commit path flattened the whole root back into one text block

That destroyed the structure the selection paths still referred to.

What fixed it

Editable now accepts snapshotFromDom(...).

EditableTextBlocks uses that seam to:

• keep the current descendant structure
• read fresh text from each rendered data-slate-node="text" owner
• replace only text-leaf content on commit

That keeps mixed-inline edits honest:

• text changes commit from real DOM input
• inline wrappers survive
• selection paths still point at real nodes after commit

Why this works

For a public editor surface, DOM reconciliation must preserve the editor shape the surface claims to support.

If the surface says “mixed inline is real” but DOM commits collapse everything back into one text node, the public API is lying.

The durable seam is not “extract all plain text from the root.” It is “preserve the current tree shape and refresh the text leaves that DOM input actually changed.”

Reusable rule

For slate-react-v2 public editing surfaces:

• plain-text root extraction is only acceptable for plain-text proof surfaces
• once a surface claims mixed-node support, DOM commit must preserve that node structure

If typing or paste makes the structure collapse while the visible text still looks correct, the reconciliation seam is too shallow.

Related issues

• 2026-04-04-v2-editable-blocks-can-be-the-first-public-editor-surface.md
• 2026-04-04-v2-editable-roots-should-own-mount-selection-sync-and-dom-commit.md