EPUB Profile
Editors:
- Hadrien Gardeur
Participate:
Introduction
While EPUB publications can mostly be converted directly to the Readium Web Publication Manifest, a number of collection roles and properties remain specific to EPUB.
This profile is meant to facilitate backward compatibility with EPUB and ensure that these specialized elements are not lost when converting to the Readium Web Publication Manifest.
This profile relies on:
- a declaration of conformance with this Profile,
- some restrictions on the resources of the readingOrder,
- the definition of additional collection roles,
- the definition of additional Link properties,
- the use of the encryption module.
1. Declaring conformance with the EPUB Profile
In order to declare that it conforms to the EPUB Profile, a Readium Web Publication Manifest must include a conformsTo key in its metadata section, with https://readium.org/webpub-manifest/profiles/epub as value.
2. Restrictions on resources in the readingOrder
A Readium Web Publication Manifest that conforms to the EPUB Profile must strictly reference XHTML documents (application/xhtml+xml) in its readingOrder.
While EPUB itself allows SVG and other formats as long as an XHTML fallback is provided, this is not the case for this profile, which requires to reverse the fallback chain.
3. Collection Roles
| Role | Semantics | Compact? | Required? |
|---|---|---|---|
| landmarks | Identifies the collection that contains a list of points of interest. | Yes | No |
| loa | Identifies the collection that contains a list of audio resources. | Yes | No |
| loi | Identifies the collection that contains a list of illustrations. | Yes | No |
| lot | Identifies the collection that contains a list of tables. | Yes | No |
| lov | Identifies the collection that contains a list of videos. | Yes | No |
| pageList | Identifies the collection that contains a list of pages. | Yes | No |
4. Link Properties
This profile defines additional Link properties:
| Key | Semantics | Type | Values |
|---|---|---|---|
| contains | Identifies content contained in the linked resource, that cannot be strictly identified using a media type. | Array | mathml, onix, remote-resources, js, svg or xmp |
| layout | Hint about the nature of the layout for the linked resources. | String | fixed or reflowable |
contains
While the media type is the main way to identify the nature of a resource in a Link Object, in certain cases it isn’t sufficient because:
- a number of metadata standards either rely on XML and JSON without defining a specific media type (ONIX, XMP);
- the media type doesn’t indicate if an HTML/XHTML resource contains MathML, SVG or Javascript, or if some of its resources are not available in the package.
contains is meant to convey that information in the Properties Object using an array of string values.
{
"href": "record.xml", "rel": "record", "type": "application/xml",
"properties": {
"contains": ["onix"]
}
}
{
"href": "chapter1.html", "type": "text/html",
"properties": {
"contains": ["svg", "remote-resources"]
}
}
layout
The layout property defaults to reflowable for text resources and fixed for images or videos.
Using fixed it can also indicate that an HTML document has a viewport with a fixed size.
{
"href": "page1.html", "type": "text/html",
"properties": {
"layout": "fixed"
}
}