EPUB 3.0 Indexes 1.0

Adoption Readiness Roadmap  

Version 2015-05-18

Supporting tools/documents

1. Samples

2. EPUBCheck support

3. Support in EPUB Conformance Test Suite (epubtest.org)

4. Authoring tool support

5. Reading system support

a. Readium (JS & SDK)

b. Other open source

c. Commercial reading systems

6. Primer/best practice documentation

Deployment impact

7. Backwards compatibility assessment

a. Legacy EPUB 2 RS

b. EPUB 3.0 RS

c. EPUB 3.01 RS

8. Fallback feasibility assessment

9a. Polyfillability assessment

9b. Browser compatibility assessment

10. Accessibility implications assessment

Supporting tools/documents

1. Samples

The specification contains samples of individual files (Package Document, Navigation Document, Content Document(s)), in Appendixes B and E.

Algebra book in EDUPUB samples has an index encoded using the spec and additional EDUPUB samples are being developed; those that have indexes will use the spec.. https://github.com/IDPF/edupub/tree/master/samples/linear-algebra/EPUB 

ASI’s Indexing for Editors and Authors - with single index document indexing-for-eds-and-auths-3f

ASI’s Indexing for Editors and Authors - with multiple index documents and collections element indexing-for-eds-and-auths-3md

2. EPUBCheck support

Romain Deltour reports that the Indexes Spec will be included in version 4.0 scheduled for sometime in 2015 Q2

3. Support in EPUB Conformance Test Suite (epubtest.org)

Test files have been developed.  They are available for download per the links above, but they are not yet in the core test suite since they are not yet final specifications.

The Working Group will take on the responsibility of creating additional test cases, in close collaboration with Marisa DeMeglio. These tests would include allowable variations in tagging and usage of epub-types not presented in the basic test files.

4. Authoring tool support

All three producers of stand-alone indexing software (CINDEX, Macrex, Sky Index) have been approached and informed about the specification but have not committed to integrating it into their product at this time.  

Leverage Technologies’ HTML/Prep software utilizes a very basic tagging scheme to generate tagging compliant to the Indexes Spec. Stand-alone indexing software (above) can output such a tagging scheme, or the scheme could be produced by other software or even manually.  

Publishers who utilize embedded indexing in XML (e.g., DocBook) generally store their data in their own flavor of XML and write their own tools to convert it to other formats as needed and generate the index.  We anticipate that some publishers will incorporate the specification into their automated production workflow. For example, two of Bill Kasdorf's consulting clients are incorporating the Indexing markup into the XML models on which their new infrastructures are based, both of which are designed to output EPUBs that incorporate the Index markup.

Adobe InDesign has informally committed to implementing after Spec approval (informal comment at DB’2014). Outreach to the InDesign engineering team is on-going.

O’Reilly’s Atlas Platform supports an early version of the spec now and will update to current (publicly stated by Sanders Kleinfeld in January 2015 ASI’s Key Words article).

VitalSource will be incorporating the spec in a future update to their content submission guidelines for publishers (email from Rick Johnson).

5. Reading system support

a. Readium (JS & SDK)

Our understanding is that the necessary resources are not immediately available to implement the Specification. The likely time-frame for implementation needs to be discussed with the Readium team.

 b. Other open source

The Working Group is not aware of any planned open source implementation.

c. Commercial reading systems

Helicon Books has expressed interest in implementing the standard [comment from Ori Idan].

Other reading system developers have been contacted. Until the Spec is approved, no commitments are expected.

6. Primer/best practice documentation

Specification examples and informative passages are intended to serve as best practice guidelines.

Deployment impact

7. Backwards compatibility assessment

What will be the impact of content deployment on the following categories of RS (assuming that they have not yet been updated to explicitly support the given specification)?

a. Legacy EPUB 2 RS

Same as standard EPUB 3.0.1.

b. EPUB 3.0 RS

Same as standard EPUB 3.0.1.

c. EPUB 3.01 RS

A Publication conforming to the EPUB Indexes Specification is perfectly readable in compliant EPUB 3.0.1 Reading Systems. The Specification mostly adds a number of new properties for use in the epub:type attribute.

8. Fallback feasibility assessment

Describe any explicit fallback behaviors incorporated in the given specification.

Because the Specification is entirely backwards-compatible, no explicit fallback mechanisms are necessary for this spec (see item 7 above) and none are provided.

9a. Polyfillability assessment

Can support for the given feature(s) be added via a JS polyfill (embedded in content)?

Basic interaction with an index as described and encoded in the Specification does not require any new features.  In its Appendix, however, the Indexes Specification lays out a number of potential new functionalities.  Some of these could be implemented via Javascript embedded in content documents.  For example, in the case of a generic cross-reference such as “See also names of specific battles,” the Specification provides the necessary “hooks and handles” for the RS to permit the user to activate a popup list of these specific battle names and select one. This could be done using JS.

9b. Browser compatibility assessment

Does implementation of the given feature(s) require changes to the underlying browser engines of RS?

No.  All functionality, including the potential new functionality suggested in Appendix C, rely on long-standing basic browser functionality such as popup windows, display of breadcrumb trails, ID/IDREF links, etc.

10. Accessibility implications assessment

Are there any noteworthy (positive or negative) implications on accessibility in the given feature(s)?

The Indexes Specification generally increases the semantic richness of the Content Document markup, so it is likely to generally enhance accessibility by enabling assistive technology to identify the various components of an index (e.g. entries, locators, etc.).