# betteroffice-pptx-edit
The collaborative PPTX deck model, backed by Yrs.
`DeckSession` owns the shared document. Slide order, slides, shapes, and text
stories are separate shared types, so reordering slides does not conflict with
editing text on one of them. Text stories reuse the same one-story-is-one-CRDT-
text rule as the DOCX editing core.
`DeckUndoManager` tracks local user-origin transactions only; remote updates
stay out of local history.
Hosts edit through version-checked batches: `DeckSession::version`,
`read_content` and `find_text` return story text with the session version it
was read at, and `apply_edits` resolves every step against that version, stages
the whole batch on a private replica, rehearses its update, and adopts it as one
transaction (one undo step by default) or returns an `EditRefusal` with the deck,
history and id allocation untouched. `validate_edits` runs the same checks
without changing anything. Proposal previews and acceptance share the staging.
`structured` exports the committed deck read-only: `DeckSession::export_structured`
and `export_markdown` for a session, `export_pptx_structured` and
`export_pptx_markdown` for bytes, and `render_pptx_markdown` for content read
earlier. One walker reads the current shape tree, projects stories as
`read_content` does, maps seeded shapes back to their retained source XML, and
admits records within block and byte budgets. `paragraph` holds the
paragraph-property cascade and list numbering the renderer shares.
State vectors, diffs, and updates are standard Yrs v1, so any transport that
speaks Yjs sync-v1 works.
Comments use a separate shared map. Saving patches existing XML and preserves
untouched comment parts byte for byte. Deleting a thread removes its known
replies; a reply added concurrently becomes a root when its parent is absent,
so both clients and saved files retain it.
The current deck schema is 2.2. Opening migrates released 1.0, 2.0 and 2.1
snapshots; attaching the original package with `open_from_update_with_source`
restores source properties. Older clients reject new-schema updates;
collaborators upgrade together or exchange saved PPTX files.
Default text overflow settings and starting slide numbers remain omitted from
package JSON.
Used by [betteroffice-pptx](https://crates.io/crates/betteroffice-pptx). The
`wasm` feature exposes the JavaScript surface consumed by
[@betteroffice/pptx](https://www.npmjs.com/package/@betteroffice/pptx).
Part of [BetterOffice](https://betteroffice.dev). Apache-2.0.
`add_picture` inserts PNG, JPEG, GIF, BMP, TIFF, WebP, or SVG bytes (up to 8 MiB).
Pictures synchronize with the shared deck and resolve through `media_bytes` before save.
`bring_to_front`, `send_to_back`, `bring_forward`, and `send_backward` arrange slide objects.