9. directionalityFinder

9. directionalityFinder
	Chapter 6. Configuration elements

<directionalityFinder>
  Content: [ class [ property ]* ]?
</directionalityFinder>

<class>
  Content: Java class name
</class>

<property
  name = NMTOKEN matching [_a-zA-Z][_a-zA-Z0-9]*
  type = (boolean|byte|char|short|int|long|float|double|
          String|URL)
  value = string
/>

Register directionalityFinder specified by class with XXE. A directionalityFinder is some code used by the "Bidi Support" add-on to determine the directionality —left-to-right or right-to-left— of any XML element.

Child elements of directionalityFinder:

class: Register directionalityFinder implemented in the Java™ language by class class (which itself implements interface com.xmlmind.xmledit.edit.DirectionalityFinder).
property: Property child elements may be used to parametrize a newly created directionalityFinder. See bean properties.

A directionalityFinder element having no class child element may be used to discard registered directionalityFinder.

XHTML configuration: the directionality of an XML element is determined by following a complex set of rules involving the dir attribute and the bdi and bdo specialized elements. These rules are specified in the HTML specification.

<directionalityFinder>
  <class>com.xmlmind.xmledit.edit.HTMLDirectionalityFinder</class>
</directionalityFinder>

DITA and DocBook configurations: the directionality of an XML element is determined by examining the value of its (possibly inherited) dir attribute.

<directionalityFinder>
  <class>com.xmlmind.xmledit.edit.HTMLDirectionalityFinder</class>
  <property name="options" type="String" value="dir ltr rtl lro rlo" />
</directionalityFinder>

TEI Lite configuration: the only way to determine the directionality of an XML element is determined by examining the value of its (possibly inherited) xml:lang attribute. For example, attribute xml:lang="ar-EG" —Arabic, Egypt— implies that the directionality of an element is right-to-left.

<directionalityFinder>
  <class>com.xmlmind.xmledit.edit.HTMLDirectionalityFinder</class>
  <property name="options" type="String" value="xml:lang" />
</directionalityFinder>

XXE uses the following specification to determine whether a language imply a right-to-left text directionality:

ar ar- ara ara- -arab
arc arc
dv dv- div div
fa fa- fas fas
ha ha- hau hau
he he- heb heb- -hebr
khw khw
ks ks- kas kas
ku ku- kur kur
ps ps- pus pus
ur ur- urd urd
yi yi- yid yid

The above specification reads: Arabic, Aramaic, Divehi, Persian, Hausa, Hebrew, Khowar, Kashmir, Kurdish, Pashto, Urdu, Yiddish and also all their country variants (e.g. "ar-EG" starting with prefix "ar-" specified above is Arabic, Egypt).

Any other language which use the Arabic (having the "-arab" suffix specified above) or the Hebrew (having the "-hebr" suffix specified above) scripts also imply a right-to-left text directionality. For example: "tr-TR-arab", Turkish, Turkey, but written using the Arabic alphabet.

This specification may be customized by specifying Java™ system property XXE_RTL_LANG, either using a java command-line option (e.g. -DXXE_RTL_LANG=...) or by adding a property configuration element to a customize.xxe file.


8. detect		9.1. `HTMLDirectionalityFinder`, a configurable implementation of `DirectionalityFinder`