Fixed-Layout Documents
Since v0.1.4, EPUB Parser supports Fixed-Layout Documents by EPUB::Publication::FixedLayout module.
It is set “on” when rendition
property exists in prefix
attribute of package
element in rootfile.
EPUB Fixed-Layout defines some additional properties to see how to render Content Documents. This EPUB Parser library supports it by providing convenience methods to know how to render.
Methods for EPUB::Publication::Package
#using_fixed_layout
It is true
when package@prefix
attribute has rendition
property.
parser = EPUB::Parser::Publication.new(<<OPF)
<package version="3.0"
unique-identifier="pub-id"
xmlns="http://www.idpf.org/2007/opf"
prefix="rendition: http://www.idpf.org/vocab/rendition/#">
</package>
OPF
package = parser.parse_package
package.using_fixed_layout # => true
And you can set by yourself:
package.using_fixed_layout = true
package.prefix # => {"rendition"=>"http://www.idpf.org/vocab/rendition/#"}
Common Methods
Methods below are provided for
- EPUB::Publication::Package::Metadata,
- EPUB::Publication::Package::Spine::Itemref,
- EPUB::Publication::Package::Manifest::Item and
- EPUB::ContentDocument::XHTML(and its subclasses).
#rendition_layout, #rendition_orientation and #rendition_spread
rendition:xxx
property is specified by meta
elements in /package/metadata
and properties
attribute of /package/spine/itemref
elements in EPUB Publications. You are recommended to use rendition_xxx
attribute to set them although you can do it by manipulating EPUB::Publication::Package::Metadata and EPUB::Publication::Package::Spine::Itemrefs directly. It is the reason why it is recommended that you must manipulate some objects not only one object to set a document’s rendition:layout
to, for instance, reflowable
; Metadata::Meta and Spine::Itemref#properties. It is bothered and tends to be mistaken, so you’re strongly recommended to use not them but rendition_layout
.
Usage is simple. Just read and write attribute values.
.rendition_layout # => "reflowable"
.rendition_layout = 'pre-paginated'
.rendition_layout # => "pre-paginated"
itemref.rendition_layout # => "pre-paginated"
itemref.rendition_layout = "reflowable"
itemref.rendition_layout # => "reflowable"
These methods are defined for EPUB::Publication::Package::Metadata, EPUB::Publication::Package::Spine::Itemref, EPUB::Publication::Package::Manifest::Item and EPUB::ContentDocument::XHTML. Methods for Metadata and Itemref are primary and ones for Item and ContentDocument are simply delegated to Itemref.
aliases
Each attribute rendition_xxx
has alias attribute as just xxx
.
.orientation = 'portrait'
.orientation # => "portrait"
.rendition_orientation # => "portrait"
#reflowable? and #pre_paginated?
Predicate methods #reflowable?
and #pre_paginated?
which are shortcuts for comparison rendition_layout
to arbitrary property value.
itemref.rendition_layout = 'pre-paginated'
itemref.reflowable? # => false
itemref.pre_paginated? # => true
#make_reflowable and make_pre_paginated
#make_reflowable
(alias: #reflowable!
) and #make_pre_paginated
(alias: #pre_paginated!
) can be used instead of calling rendition_layout
and comparing it with String
"reflowable"
or "pre-paginated"
, they help you from mistyping such like "pre_paginated"
(using underscore rather than hyphen).
Methods for EPUB::Publication::Package::Spine::Itemref
#page_spread
FixedLayout module adds property center
to EPUB::Publication::Package::Spine::Itemref#page_spread’s available properties, which are ever left
and right
.
itemref.page_spread # => nil
itemref.page_spread = 'center'
itemref.page_spread # => "center"
itemref.properties # => ["rendition:page-spread-center"]
References
- Fixed-Layout Documents on IDPF site