XFA Specification
New XFA Template Features
971
Data description element, version 2.1
XML data documents consumed by XFA processing applications may include data description elements.
Such elements provide information used during data binding to ensure the XFA Form DOM for the data
corresponds to a desired schema.
Default data binding to include attribute data, version 2.1
XML data consumed by an XFA processing application frequently uses attributes to supply data. To
accommodate such use, the config grammar default value for the
attribute
property has been changed
to "
preserve
".
Previously the default value for the
attribute
property was "
ignore
".
Subform scope option, version 2.1
It is now possible to make a subform transparent to the data binding process without making it nameless.
Hence it can be referenced in XFA-SOM expressions even though it is a non-entity for data binding.
Layout
Support for right-to-left text flow, version 2.4
Locales in which text flows right to left are now supported. Any block of text may contain any mixture of
left to right and right to left flow. In addition draws can specify a locale (and therefore a default flow
direction for text).
See “Flowing Text Within a Container” on page 62.
Conditional breaking, version 2.4
Layout markup can supply a scripting expression to decide at layout time whether or not a particular break
should be taken.
See “Break Conditions” on page 216.
Nesting tables, version 2.4
Tables may nest to any depth.
See “Tables” on page 254.
Automatically breaking layout, version 2.1
Subforms may now specify their appearance in the event their content forces them to grow across a page
boundary. This appearance may specify the inclusion of a leader subform at the top of a subform break or
the inclusion of a trailer subform at the bottom of a subform break.
Containers may describe the appearance of borders around containers that break across pages.
Dynamic layout, version 2.1
XFA supports dynamic forms. Such forms automatically adjust depending on data being entered. In a
dynamic form, the arrangement of the form is determined by the arrangement of the data. For example, if
the data contains enough entries to fill a particular subform 7 times, then the Form DOM incorporates 7
copies of the subform. Depending on the template, subforms may be omitted entirely or rearranged, or
one subform out of a set selected by the data. Dynamic forms are more difficult to design than static forms
but they do not have to be redesigned as often when the data changes. In addition dynamic forms can
provide an enhanced visual presentation to the user because unused portions of the form are omitted
rather than simply left blank.
In contrast, XFA 2.0 supports only static forms. In a static form, the template is laid out exactly as the form is
to be presented. When the template is merged with data, some fields are filled in. Any fields left unfilled