4.1.3 Documents & document variants

A document can exist in multiple variants, e.g. in multiple languages. A document in itself does not consist of much, most of the data is contained in the document variants. From another point of view (which closer matches the implementation), one could say that the repository server actually manages document variants, which happen to share a few properties (most notably their identity) through the concept of a document.

A document has always at least one document variant, a document cannot exist by itself without variants.

A document is identified uniquely by its ID, a document variant is identified by the triple {document ID, branch, language}.

If you are not interested in using variants, you can mostly ignore them. In that case each document will always be associated with exactly one document variant. Therefore, often when we speak about a document in Daisy, we implicitly mean "a certain variant of a document" (a "document variant"). In a practical working environment like the Daisy Wiki, the branch and language which identify the particular variant of the document are usually a given (Daisy Wiki: configured per site), and you'll only work with document IDs, so it is as if the existence of variants is transparent.

Refer to the diagram above to see if a certain aspect applies to a document, a document variant, or a version of a document variant.

For more details on this topic, see variants.