/ 
Geo-GML-0.15
River stage one • 1 direct dependent • 1 total dependent
/ Geo::GML

NAME

Geo::GML - Geography Markup Language processing

INHERITANCE

Geo::GML has extra code in
  Geo::GML::GeoPoint

Geo::GML
  is a XML::Compile::Cache
  is a XML::Compile::Schema
  is a XML::Compile

SYNOPSIS

use Geo::GML ':gml321';

my $gml = Geo::GML->new('READER', version => '3.2.1');

# see XML::Compile::Cache on how to use readers and writers
my $data = $gml->reader("gml:GridCoverage")->($xmlmsg);
my $xml  = $gml->writer($sometype)->($doc, $perldata);

# or without help of the cache, XML::Compile::Schema
my $r    = $gml->compile(READER => $sometype);
my $data = $r->($xml);

# super simple
my ($type, $data) = Geo::GML->from('data.xml');

# overview (large) on all defined elements
$gml->printIndex;

# To discover the perl datastructures to be passed
print $gml->template("gml:Surface");

# autoloaded logic to convert Geo::Point into GML
$data->{...somewhere...} = $gml->GPtoGML($objects);

DESCRIPTION

Provides access to the GML definitions specified in XML. The details about GML structures can differ, and therefore you should be explicit which versions you understand and produce.

If you need the <b>most recent</b> version of GML, then you get involved with the ISO19139 standard. See CPAN module Geo::ISO19139.

The first releases of this module will not powerful, but hopefully people contribute. For instance, an example conversion script between various versions is very welcome! It would be nice to help each other. I will clean-up the implementation, to make it publishable, but do not have the knowledge about what is needed.

METHODS

Constructors

Geo::GML->from(XMLDATA, OPTIONS)

    Read a EOP structure from a data source, which can be anything acceptable by dataToXML(): a XML::LibXML::Element, XML as string or ref-string, filename, filehandle or known namespace.

    Returned is the product (the type of the root node) and the parsed data-structure. The EOP version used for decoding is autodetected, unless specified.

    See examples/read_gml.pl

    example:

    my ($type, $data) = Geo::GML->from('data.xml');

Geo::GML->new('READER'|'WRITER'|'RW', OPTIONS)

    Option            --Defined in     --Default
allow_undeclared                     <true>
any_element         XML::Compile::Cache  ATTEMPT
hook                XML::Compile::Schema  undef
hooks               XML::Compile::Schema  []
ignore_unused_tags  XML::Compile::Schema  <false>
key_rewrite         XML::Compile::Schema  []
opts_readers        XML::Compile::Cache  []
opts_rw             XML::Compile::Cache  <some>
opts_writers        XML::Compile::Cache  []
prefixes                             undef
schema_dirs         XML::Compile     undef
typemap             XML::Compile::Schema  {}
version                              <required>

    . allow_undeclared => BOOLEAN

      In the optimal case, all types used in your application are declared during the initiation phase of your program. This will make it easy to write a fast daemon application, or transform your program into a daemon later. So: "false" would be a good setting. However, on the moment, the developer of this module has no idea which types people will use. Please help me with the specs!

      All any elements will be ATTEMPTed to be processed at run-time by default.

      The GML specification will require PREFIXED key rewrite, because the complexity of namespaces is enormous. Besides, mixed elements are processed as STRUCTURAL by default (mixed in texts ignored).

    . any_element => CODE|'TAKE_ALL'|'SKIP_ALL'|'ATTEMPT'

    . hook => ARRAY-WITH-HOOKDATA | HOOK

    . hooks => ARRAY-OF-HOOK

    . ignore_unused_tags => BOOLEAN|REGEXP

    . key_rewrite => HASH|CODE|ARRAY-of-HASH-and-CODE

    . opts_readers => HASH|ARRAY-of-PAIRS

    . opts_rw => HASH|ARRAY-of-PAIRS

    . opts_writers => HASH|ARRAY-of-PAIRS

    . prefixes => ARRAY|HASH

      Prefix abbreviations, to be used by cache object. Which prefixes are defined depends on the schema version.

    . schema_dirs => DIRECTORY|ARRAY-OF-DIRECTORIES

    . typemap => HASH

    . version => VERSION|NAMESPACE

      Only used when the object is created directly from this base-class. It determines which GML syntax is to be used. Can be a VERSION like "3.1.1" or a NAMESPACE URI like 'NS_GML_300'.

Accessors

$obj->addHook(HOOKDATA|HOOK|undef)

$obj->addHooks(HOOK, [HOOK, ...])

$obj->addKeyRewrite(PREDEF|CODE|HASH, ...)

$obj->addSchemaDirs(DIRECTORIES|FILENAME)

Geo::GML->addSchemaDirs(DIRECTORIES|FILENAME)

$obj->addSchemas(XML, OPTIONS)

$obj->addTypemap(PAIR)

$obj->addTypemaps(PAIRS)

$obj->allowUndeclared([BOOLEAN])

$obj->direction

    Returns 'READER', 'WRITER', or 'RW'.

$obj->hooks

$obj->prefix(PREFIX)

$obj->prefixFor(URI)

$obj->prefixes([PAIRS|ARRAY|HASH])

$obj->useSchema(SCHEMA, [SCHEMA])

$obj->version

    GML version, for instance '3.2.1'.

Compilers

$obj->compile(('READER'|'WRITER'), TYPE, OPTIONS)

$obj->compileAll(['READER'|'WRITER'|'RW', [NAMESPACE]])

Geo::GML->dataToXML(NODE|REF-XML-STRING|XML-STRING|FILENAME|FILEHANDLE|KNOWN)

$obj->reader(TYPE|NAME, OPTIONS)

$obj->template('PERL'|'XML', TYPE, OPTIONS)

    See XML::Compile::Schema::template(). This will create an example of the data-structure based on GML. All OPTIONS are passed to the template generator, the only reason to have this method, is to avoid the need to collect all the GML XML files yourself.

    Option              --Defined in     --Default
abstract_types        XML::Compile::Schema  'IGNORE'
attributes_qualified  XML::Compile::Schema  <undef>
elements_qualified    XML::Compile::Schema  <undef>
include_namespaces    XML::Compile::Schema  <true>
indent                XML::Compile::Schema  " "
show_comments         XML::Compile::Schema  ALL

    . abstract_types => 'ERROR'|'IGNORE'|'ACCEPT'

    . attributes_qualified => BOOLEAN

    . elements_qualified => 'ALL'|'TOP'|'NONE'|BOOLEAN

    . include_namespaces => BOOLEAN

    . indent => STRING

    . show_comments => STRING|'ALL'|'NONE'

    example:

    use Geo::GML;
use Geo::GML::Util     qw/NS_GML_321/;
use XML::Compile::Util qw/pack_type/;
my $gml   = Geo::GML->new(version => NS_GML_321);

# to simplify the output, reducing often available large blocks
my @types = qw/gml:MetaDataPropertyType gml:StringOrRefType
   gml:ReferenceType/;
my %hook  = (type => \@collapse_types, replace => 'COLLAPSE');

# generate the data-structure
my $type  = 'gml:RectifiedGridCoverage';  # any element name
print $gml->template(PERL => $type, hook => \%hook);

$obj->writer(TYPE|NAME)

Helpers

$obj->GPtoGML(OBJECT, OPTIONS)

Administration

$obj->declare('READER'|'WRITER'|'RW', TYPE|ARRAY-of-TYPES, OPTIONS)

$obj->elements

$obj->findName(NAME)

$obj->findSchemaFile(FILENAME)

Geo::GML->findSchemaFile(FILENAME)

$obj->importDefinitions(XMLDATA, OPTIONS)

$obj->knownNamespace(NAMESPACE|PAIRS)

Geo::GML->knownNamespace(NAMESPACE|PAIRS)

$obj->namespaces

$obj->printIndex([FILEHANDLE], OPTIONS)

    List all the elements which can be produced with the schema. By default, this only shows the elements and excludes the abstract elements from the list. The selected FILEHANDLE is the default to print to.

    Option       --Defined in         --Default
show_declared  XML::Compile::Cache  <true>

    . show_declared => BOOLEAN

$obj->types

$obj->walkTree(NODE, CODE)

DETAILS

DIAGNOSTICS

Error: cannot find pre-installed name-space files

    Use $ENV{SCHEMA_LOCATION} or new(schema_dirs) to express location of installed name-space files, which came with the XML::Compile distribution package.

Error: don't known how to interpret XML data

SEE ALSO

This module is part of Geo-GML distribution version 0.15, built on March 19, 2009. Website: http://perl.overmeer.net/geo/ All modules in this suite: "Geo::GML", "Geo::ISO19139", "Geo::EOP", "Geo::Point", "Geo::Proj4", "Geo::WKT", and "Math::Polygon".

Please post questions or ideas to http://geo-perl@list.hut.fi|the Geo-Perl mailinglist

COPYRIGHTS

License of the CODE

Copyrights of the perl code and the related documentation by 2008-2009 by Mark Overmeer. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://www.perl.com/perl/misc/Artistic.html

License of the SCHEMAS

The included schemas are copyrighted by the Open Geospatial Consortium, Inc. They are unmodified copied from the files at http://schemas.opengis.net. Read OGCs disclaimer and copyright statements on documentation and software at http://www.opengeospatial.org/ogc/legal. The license text is also included in this CPAN distribution.