Chapter 4, Exchanging Data Between an External Application
and a Basic XFA Form
XFA Specification
Localization and Canonicalization
140
nullType
xsi
xsi
isNull
1
1
value
"A Book"
""
contains
data
data
Output XML
<title xsi:nil="true">A Book</title>
<title xsi:nil="true" />
Note that
nullType
cannot have the value
xsi
when
contains
is set to
metadata
.
Logical Equivalence
The rules stated above ensure that every implementation produces logically equivalent output given the
same inputs. Logical equivalence includes exact character-for-character reproduction of the content of
elements that map (or would map, if they were within the document range) to data values, including
attribute values. However it does not include white space within the character data of elements that map
(or would map) to data groups. Hence, the data unloader may insert white space characters and newlines
within elements representing data groups. This is useful for improving readability. When the output XML
data document is loaded into a new XML Data DOM the new XML Data DOM does not necessarily have the
same content as the original XML Data DOM, however the XFA Data DOM that derives from it has the same
content as the original XFA Data DOM.
Localization and Canonicalization
This section explains how XFA processing applications support locales (languages or nation-languages)
when loading data into the XFA Data DOM or editing data in the Form DOM and when unloading,
displaying, and printing such data.
Before beginning this section, it is important to understand that all data in the XFA Data DOM and the
Form DOM is represented in a standardized, locale-agnostic format, called
canonical format.
Canonical
format plays a role in the following conversions:
●
Input parsing.
Data to be loaded into the XFA Data DOM or provided by a user may be formatted in a
style unique to the locale (a
locale-dependent format)
or in canonical format. Before data is loaded into
the XFA Data DOM, the XFA processing application converts the data into canonical format, a process
called
canonicalization.
Output formatting.
After data is in the XFA Data DOM, there is eventually a need to display, save or print
the canonical data in a locale-specific format. The process of converting the canonical data into a
locale-specific form is called
localization.
●
Requirements for Localization
Satisfying Locale-Dependent User Expectations
Users in different locales have varying expectations about the formats in which they expect to provide
dates, times, numbers, and currencies. Such differences reflect ordering of information (for example,
MM/DD/YY as opposed to DD/MM/YY), the names used for units (for example, January as opposed to
janvier), and the characters/ideographs used to represent information (for example, 1998 as opposed to
).