MultilanguageString

[qnga]

I can't fully understand the intent behind MultilanguageString objects, used for example for titles. In the Readium manifest specification, a title is either a String, or a map from language to title, not both.
In the Epub Metadata Parsing Guide one can't find any mention of "singleString" either.
Since, content from dc:title is put into the map after determining the tag language, what is singleString for? Should it contain a copy of the title in the default language for metadata, computed as specified in the Epub Metadata Parsing Guide?

[mickael-menu]

Yes it's wrong, I will refactor this as a sealed class.

Here's the Swift version that should be correct: https://github.com/readium/r2-shared-swift/blob/develop/r2-shared-swift/Publication/Web%20Publication/LocalizedString.swift

[qnga]

Will we use the non-localized-case in native formats parsing? Only when no xml:lang is defined and publication has no default language? Or when there is only one variant? It looks like a shortcut for handwriting, and not designed for automatic parsing.

[mickael-menu]

Good question. You can see here that in Swift I added a fallback on xml:lang for the language of the default string, but only if there are several translations available.

The rationale was that this is redundant with publication.metadata.languages in the model. The goal of these localized strings is to provide translations when available, not to know the language of the string – unless it differs from the publication's language.

For other formats embedding a RWPM as a JSON manifest (LCPDF, audiobooks), we are parsing the JSON as-is, so the default language is definitely not added in all the strings.

(Btw we have a Slack at Readium, if you want to join: http://readium-slack.herokuapp.com/)

[qnga]

Your choice seems to be reasonable, but goes against the Epub Parsing Guide. If all people agree, it should be modified (and some other points clarified I think).

[mickael-menu]

Can you link to the part where you think this goes against the guide?

[qnga]

While the default context is very flexible in the way each metadata can be represented, when parsing a publication in the streamer we always use the most complex form for each metadata to harmonize our output.

The title of a publication is an object where each key is a BCP 47 language tag and each value of this key is a string.

To determine the default language for metadata, check:
if the package has an xml:lang attribute;
the primary language of the publication.

I'm not sure, but if I have to give an interpretation of this, I will say that the unlocalized version should not be used in Epub parsing.

[mickael-menu]

So we're actually going to change the model to remove the "nonlocalized" case.

It looks like that on Kotlin right now:

https://github.com/readium/r2-shared-kotlin/blob/dba8aad55b0126873c9b7ebe9aff69aa55dec939/r2-shared/src/main/java/org/readium/r2/shared/publication/webpub/LocalizedString.kt#L23-L28

Before finalizing this form, I'll have to check if this is a non-breaking change on Swift.

[qnga]

package org.readium.r2.shared.publication.webpub

That's only for webpub publications, or Readium manifest and publications will use parts of the webpub model?

[mickael-menu]

It's for the Readium Web Publication Manifest model, not for the W3C Web Publication.

In the parent package will reside the models used in R2: Publication (which will delegate to the WebPublication for metadata and augment it with features needed by the navigator), Locator, UserSettings, etc.

[mickael-menu]

Actually I moved everything under publication, and merged Publication and WebPublication together.