The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.

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.

See documentation in the base class.

METHODS

See documentation in the base class.

Constructors

See documentation in the base class.

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
  block_namespace     XML::Compile::Schema  []
  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   []
  parser_options      XML::Compile          <many>
  prefixes                                  undef
  schema_dirs         XML::Compile          undef
  typemap             XML::Compile::Cache   {}
  version                                   <required>
  xsi_type            XML::Compile::Cache   {}
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'|'SLOPPY'
block_namespace => NAMESPACE|TYPE|HASH|CODE|ARRAY
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
parser_options => HASH|ARRAY
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|ARRAY
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'.

xsi_type => HASH|ARRAY

Accessors

See documentation in the base class.

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

See "Accessors" in XML::Compile::Schema

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

See "Accessors" in XML::Compile::Schema

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

See "Accessors" in XML::Compile::Schema

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

See "Accessors" in XML::Compile

$obj->addSchemas(XML, OPTIONS)

See "Accessors" in XML::Compile::Schema

$obj->addTypemap(PAIR)

See "Accessors" in XML::Compile::Schema

$obj->addTypemaps(PAIRS)

See "Accessors" in XML::Compile::Schema

$obj->addXsiType([HASH|ARRAY|LIST])

See "Accessors" in XML::Compile::Cache

$obj->allowUndeclared([BOOLEAN])

See "Accessors" in XML::Compile::Cache

$obj->anyElement('ATTEMPT'|'SLOPPY'|'SKIP_ALL'|'TAKE_ALL'|CODE)

See "Accessors" in XML::Compile::Cache

$obj->blockNamespace(NAMESPACE|TYPE|HASH|CODE|ARRAY)

See "Accessors" in XML::Compile::Schema

$obj->direction()

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

$obj->hooks([READER|WRITER])

See "Accessors" in XML::Compile::Schema

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

See "Accessors" in XML::Compile::Cache

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

See "Accessors" in XML::Compile::Schema

$obj->version()

GML version, for instance '3.2.1'.

Prefix management

See documentation in the base class.

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

See "Prefix management" in XML::Compile::Cache

$obj->learnPrefixes(NODE)

See "Prefix management" in XML::Compile::Cache

$obj->prefix(PREFIX)

See "Prefix management" in XML::Compile::Cache

$obj->prefixFor(URI)

See "Prefix management" in XML::Compile::Cache

$obj->prefixed(TYPE|(NAMESPACE,LOCAL))

See "Prefix management" in XML::Compile::Cache

$obj->prefixes([PARAMS])

See "Prefix management" in XML::Compile::Cache

Compilers

See documentation in the base class.

$obj->addCompileOptions(['READERS'|'WRITERS'|'RW'], OPTIONS)

See "Compilers" in XML::Compile::Cache

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

See "Compilers" in XML::Compile::Schema

$obj->compileAll(['READERS'|'WRITERS'|'RW', [NAMESPACE]])

See "Compilers" in XML::Compile::Cache

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

See "Compilers" in XML::Compile

$obj->initParser(OPTIONS)
Geo::GML->initParser(OPTIONS)

See "Compilers" in XML::Compile

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

See "Compilers" in XML::Compile::Cache

$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  'ERROR'
  attributes_qualified  XML::Compile::Schema  <undef>
  elements_qualified    XML::Compile::Schema  'TOP'
  include_namespaces    XML::Compile::Schema  <true>
  indent                XML::Compile::Schema  " "
  key_rewrite           XML::Compile::Schema  []
  show_comments         XML::Compile::Schema  ALL
  skip_header           XML::Compile::Schema  <false>
abstract_types => 'ERROR'|'ACCEPT'
attributes_qualified => BOOLEAN
elements_qualified => 'ALL'|'TOP'|'NONE'|BOOLEAN
include_namespaces => BOOLEAN|CODE
indent => STRING
key_rewrite => HASH|CODE|ARRAY-of-HASH-and-CODE
show_comments => STRING|'ALL'|'NONE'
skip_header => BOOLEAN

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)

See "Compilers" in XML::Compile::Cache

Helpers

$obj->GPtoGML(OBJECT, OPTIONS)

See "Helpers" in Geo::GML::GeoPoint

Administration

See documentation in the base class.

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

See "Administration" in XML::Compile::Cache

$obj->doesExtend(EXTTYPE, BASETYPE)

See "Administration" in XML::Compile::Schema

$obj->elements()

See "Administration" in XML::Compile::Schema

$obj->findName(NAME)

See "Administration" in XML::Compile::Cache

$obj->findSchemaFile(FILENAME)
Geo::GML->findSchemaFile(FILENAME)

See "Administration" in XML::Compile

$obj->importDefinitions(XMLDATA, OPTIONS)

See "Administration" in XML::Compile::Schema

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

See "Administration" in XML::Compile

$obj->namespaces()

See "Administration" in XML::Compile::Schema

$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()

See "Administration" in XML::Compile::Schema

$obj->walkTree(NODE, CODE)

See "Administration" in XML::Compile

DETAILS

See documentation in the base class.

DESCRIPTIONS

See documentation in the base class.

SEE ALSO

This module is part of Geo-GML distribution version 0.16, built on January 05, 2014. 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 https://list.hut.fi/mailman/listinfo/geo-perl|the Geo-Perl mailinglist

COPYRIGHTS

License of the CODE

Copyrights of the perl code and the related documentation by 2008-2014 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.