Complete XML structure.

[pspp] / spv-file-format.texi

@node SPSS Viewer Format
@section SPSS Viewer Format

SPSS Viewer or @file{.spv} files, here called SPV files, are written
by SPSS 16 and later to represent the contents of its output editor.
This section documents the format.  This description is detailed
enough to read SPV files, but it is probably not sufficient to
write them.

An an aside, SPSS 15 and earlier versions use a completely different
output format based on the Microsoft Compound Document Format.  This
format is not documented.

An SPV file is a Zip archive that can be read with @command{zipinfo}
and @command{unzip} and similar programs.  The final member in the Zip
archive is a file named @file{META-INF/MANIFEST.MF}.  This structure
makes SPV files resemble Java ``JAR'' files, but whereas a JAR
manifest contains a sequence of colon-delimited key/value pairs, an
SPV manifest contains the string @samp{allowPivoting=true}, without a
new-line.

The rest of the members in an SPV file's Zip archive fall into two
categories: structure and details.  ``Structure'' member names begin
with @file{outputViewer@var{nnnnnnnnnn}}, where each @var{n} is a
decimal digit, and end with @file{.xml}, and often include the string
@file{_heading} in between.  Each of these members represents some
kind of output item (a table, a heading, a block of text, etc.) or a
group of them.  The member whose output goes at the beginning of the
document is numbered 0, the next member in the output is numbered 1,
and so on.

Structure members contain XML.  This XML is sometimes self-contained,
but it often references other members in the Zip archive named as
follows:

@table @asis
@item @file{@var{prefix}_table.xml} and @file{@var{prefix}_tableData.bin}
@itemx @file{@var{prefix}_lightTableData.bin}
The structure of a table plus its data.  Older SPV files pair a
@file{@var{prefix}_table.xml} file that describes the table's
structure with a binary @file{@var{prefix}_tableData.bin} file that
gives its data.  Newer SPV files (the majority of those in the corpus)
instead include a single @file{@var{prefix}_lightTableData.bin} file
that incorporates both into a single binary format.

@item @file{@var{prefix}_warning.xml} and @file{@var{prefix}_warningData.bin}
@itemx @file{@var{prefix}_lightWarningData.bin}
Same format used for tables, with a different name.

@item @file{@var{prefix}_notes.xml} and @file{@var{prefix}_notesData.bin}
@itemx @file{@var{prefix}_lightNotesData.bin}
Same format used for tables, with a different name.

@item @file{@var{prefix}_chartData.bin} and @file{@var{prefix}_chart.xml}
The structure of a chart plus its data.  Charts do not have a
``light'' format.

@item @var{prefix}_model.xml
@itemx @var{prefix}_pmml.xml
@itemx @var{prefix}_stats.xml
Not yet investigated.  The corpus contains only one example of each.
@end table

The @file{@var{prefix}} in the names of the detail members is
typically an 11-digit decimal number that increases for each item,
tending to skip values.  Older SPV files use different naming
conventions.  Structure member refer to detail members by name, and so
their exact names do not appear to matter as long as they are unique.

@node SPV Structure Member Format
@subsection Structure Member Format

Structure members XML files claim conformance with a collection of XML
Schemas.  These schemas are distributed, under a nonfree license, with
SPSS binaries.  Fortunately, the schemas are not necessary to
understand the structure members.  To a degree, the schemas can even
be deceptive because they document elements and attributes that are
not in the corpus and lack documentation of elements and attributes
that are commonly found in the corpus.

Structure members use a different XML namespace for each schema, but
these namespaces are not entirely consistent: in some SPV files, for
example, the @code{viewer-tree} schema is associated with namespace
@indicateurl{http://xml.spss.com/spss/viewer-tree} and in other with
@indicateurl{http://xml.spss.com/spss/viewer/viewer-tree} (note the
additional @file{viewer/} directory.  In any case, the schema URIs are
not resolvable to obtain the schemas themselves.

One may ignore all of the above in interpreting a structure member.
The actual XML has a simple and straightforward form that does not
require a reader to take schemas or namespaces into account.

@table @code
@item heading
Parent: Document root or @code{heading} @*
Contents: @code{label} [@code{container} | @code{heading}]*

The root of a structure member is a @code{heading}, which represents a
section of output beginning with a title (the @code{label}) and
ordinarily followed by a container for content and possibly further
nested (sub)-sections of output.

The following attributes have been observed on both document root and
nested @code{heading} elements:

@table @asis
@item Optional attribute: @code{creator-version}
The version of the software that created this SPV file.  A string of
the form @code{xxyyzzww} represents software version xx.yy.zz.ww,
e.g.@: @code{21000001} is version 21.0.0.1.  Trailing pairs of zeros
are sometimes omitted, so that @code{21}, @code{210000}, and
@code{21000000} are all version 21.0.0.0 (and the corpus contains all
three of those forms).
@end table

The following attributes have been observed on document root
@code{heading} elements only:

@table @asis
@item Optional attribute: @code{creator}
The directory of the software that created this SPV file,
e.g. @file{C:\PROGRA~1\IBM\SPSS\STATIS~1\22} or
@file{/Applications/IBM/SPSS/Statistics/22/SPSSStatistics.app/Contents/Resources/Java/../../bin}.

@item Optional attribute: @code{creation-date-time}
The date and time at which the SPV file was written, in a
locale-specific format, e.g. @code{Friday, May 16, 2014 6:47:37 PM
PDT} or @code{lunedì 17 marzo 2014 3.15.48 CET} or even @code{Friday,
December 5, 2014 5:00:19 o'clock PM EST}.

@item Optional attribute: @code{lockReader}
Whether a reader should be allowed to edit the output.  The possible
values are @code{true} and @code{false}, but the corpus only contains
@code{false}.

@item Optional attribute: @code{schemaLocation}
This is actually an XML Namespace attribute.  A reader may ignore it.
@end table

The following attributes have been observed only on nested
@code{heading} elements:

@table @asis
@item Required attribute: @code{commandName}
The locale-invariant name of the command that produced the output,
e.g.@: @code{Frequencies}, @code{T-Test}, @code{Non Par Corr}.

@item Optional attribute: @code{visibility}
To what degree the output represented by the element is visible.  The
only observed value is @code{collapsed}.

@item Optional attribute: @code{locale}
The locale used for output, in Windows format, which is similar to the
format used in Unix with the underscore replaced by a hyphen, e.g.@:
@code{en-US}, @code{en-GB}, @code{el-GR}, @code{sr-Cryl-RS}.

@item Optional attribute: @code{olang}
The output language, e.g.@: @code{en}, @code{it}, @code{es},
@code{de}, @code{pt-BR}.
@end table

@item label
Parent: @code{heading} or @code{container} @*
Contents: text

Every @code{heading} and @code{container} holds a @code{label} as its
first child.  The root @code{heading} in a structure member always
contains the string ``Output''.  Otherwise, the text in @code{label}
describes what it labels, often by naming the statistical procedure
that was executed, e.g.@: ``Frequencies'' or ``T-Test''.  Labels are
often very generic, especially within a @code{container}, e.g.@:
``Title'' or ``Warnings'' or ``Notes''.  Label text is localized
according to the output language, e.g. in Italian a frequency table
procedure is labeled ``Frequenze''.

The corpus contains one example of an empty label, one that contains
no text.

@item container
Parent: @code{heading} @*
Contents: @code{label} [@code{table} | @code{text}]

A @code{container} serves to label a @code{table} or a @code{text}
item.

@table @asis
@item Required attribute: @code{visibility}
Either @code{visible} or @code{hidden}, this indicates whether the
container's content is displayed.

@item Optional attribute: @code{text-align}
Presumably indicates the alignment of text within the container.  The
only observed value is @code{left}.  Observed with nested @code{table}
and @code{text} elements.

@item Optional attribute: @code{width}
The width of the container in the form @code{@var{n}px}, e.g.@:
@code{1097px}.
@end table

@item text
Parent: @code{container} @*
Contents: @code{html}

@table @asis
@item Required attribute: @code{type}
One of @code{title}, @code{log}, or @code{text}.

@item Optional attribute: @code{commandName}
As on the @code{heading} element.  For output not specific to a
command, this is simply @code{log}.  The corpus contains one example
of where @code{commandName} is present but set to the empty string.

@item Optional attribute: @code{creator-version}
As on the @code{heading} element.
@end table

@item html
Parent: @code{text} @*
Contents: cdata

The cdata contains an HTML document.  In some cases, the document
starts with @code{<html>} and ends with @code{</html}; in others the
@code{html} element is implied.  Generally the HTML includes a
@code{head} element with a CSS stylesheet.  The HTML body often begins
with @code{<BR>}.  The actual content ranges from trivial to simple:
just discarding the CSS and tags yields readable results.

@table @asis
@item Required attribute: @code{lang}
This always contains @code{en} in the corpus.
@end table

@item table
Parent: @code{container} @*
Contents: @code{tableStructure}

@table @asis
@item Required attribute: @code{commandName}
As on the @code{heading} element.

@item Required attribute: @code{type}
One of @code{table}, @code{note}, or @code{warning}.

@item Required attribute: @code{subType}
The locale-invariant name for the particular kind of output that this
table represents in the procedure.  This can be the same as
@code{commandName} e.g.@: @code{Frequencies}, or different, e.g.@:
@code{Case Processing Summary}.  Generic subtypes @code{Notes} and
@code{Warnings} are often used.

@item Required attribute: @code{tableId}
A number that uniquely identifies the table within the SPV file,
typically a large negative number such as @code{-4147135649387905023}.

@item Optional attribute: @code{creator-version}
As on the @code{heading} element.  In the corpus, this is only present
for version 21 and up and always includes all 8 digits.
@end table

@item tableStructure
Parent: @code{table}
Contents: @code{dataPath}

@item dataPath
Parent: @code{tableStructure}
Contents: text

Contains the name of the Zip member that holds the table details,
e.g.@: @code{0000000001437_lightTableData.bin}.
@end table