Object Identity

PptxGenJS exposes objectName on generated slide objects that have a PowerPoint Selection Pane identity. When set, objectName is serialized to the generated object's p:cNvPr name attribute.

The explicit objectName contract applies to:

• text boxes and text-backed shapes;
• shapes;
• images, including SVG-backed images;
• charts;
• tables;
• media objects;
• slide master placeholders.

When objectName is omitted, PptxGenJS emits an internal default such as Text 0, Shape 0, Image 0, Chart 0, Table 0, or Media 0. Consumers that need stable semantic identity should set objectName explicitly instead of depending on generated default names.

Alt text

altText is a universal contract across every object kind listed above: text boxes and text-backed shapes, shapes, images (including SVG-backed images), charts, tables, and media. When set, altText is serialized to the generated object's p:cNvPr descr attribute. Images additionally fall back to the image filename for descr when altText is omitted; all other kinds emit an empty descr when altText is omitted.

Name validation

objectName values are XML-encoded before serialization. PptxGenJS also warns (via console.warn, without throwing) at generation time when a name cannot provide a stable Selection Pane identity, so identity bugs surface early instead of producing a silently broken deck:

• empty or whitespace-only names;
• names containing control characters (these are stripped during XML encoding, silently changing the stored name);
• names longer than 255 characters (may not be preserved by PowerPoint);
• duplicate objectName values emitted on a single slide (consumers that rely on unique names, such as semantic manifests, cannot disambiguate them).

These are warnings, not errors: existing decks with loose names continue to build unchanged.