Constructors¶

These constructors are base class methods to be extended, and therefore should not be accessed directly.

XML::Compile->new( [$xmldata], %options )

The $xmldata is a source of XML. See dataToXML() for valid ways, for example as filename, string or "undef".

If you have compiled all readers and writers you need, you may simply terminate the compiler object: that will clean-up (most of) the XML::LibXML objects.

 -Option        --Default
  parser_options  <many>
  schema_dirs     undef
    

Accessors¶

$obj->addSchemaDirs(@directories|$filename)

XML::Compile->addSchemaDirs(@directories|$filename)

Each time this method is called, the specified @directories will be added in front of the list of already known schema directories. Initially, the value of the environment variable "SCHEMA_DIRECTORIES" is added (therefore tried as last resort). The constructor option "schema_dirs" is a little more favorite.

Values which are "undef" are skipped. ARRAYs are flattened. Arguments are split at colons (on UNIX) or semi-colons (windows) after flattening. The list of directories is returned, in all but VOID context.

When a ".pm" package $filename is given, then the directory to be used is calculated from it (platform independently). So, "something/XML/Compile.pm" becomes "something/XML/Compile/xsd/". This way, modules can simply add their definitions via "XML::Compile->addSchemaDirs(__FILE__)" in a BEGIN block or in main. ExtUtils::MakeMaker will install everything what is found in the "lib/" tree, so also your xsd files. Probably, you also want to use knownNamespace().

example: adding xsd's from your own distribution

  # file xxxxx/lib/My/Package.pm
  package My::Package;
  use XML::Compile;
  XML::Compile->addSchemaDirs(__FILE__);
  # now xxxxx/lib/My/Package/xsd/ is also in the search path
  use constant MYNS => 'http://my-namespace-uri';
  XML::Compile->knownNamespace(&MYNS => 'my-schema-file.xsd');
  $schemas->importDefinitions(MYNS);
    

Compilers¶

$obj->dataToXML($node|REF-XML|XML-STRING|$filename|$fh|$known)

XML::Compile->dataToXML($node|REF-XML|XML-STRING|$filename|$fh|$known)

Collect $xml data, from a wide variety of sources. In SCALAR context, an XML::LibXML::Element or XML::LibXML::Document is returned. In LIST context, pairs of additional information follow the scalar result.

When a ready XML::LibXML::Node (::Element or ::Document) $node is provided, it is returned immediately and unchanged. A SCALAR reference is interpreted as reference to $xml as plain text ($xml texts can be large, and you can improve performance by passing it around by reference instead of copy). Any value which starts with blanks followed by a '<' is interpreted as $xml text.

You may also specify a pre-defined known name-space URI. A set of definition files is included in the distribution, and installed somewhere when this all gets installed. Either define an environment variable named SCHEMA_LOCATION or use new(schema_dirs) (option available to all end-user objects) to inform the library where to find these files.

According the XML::LibXML::Parser manual page, passing a $fh is much slower than pasing a $filename. However, it may be needed to open a file with an explicit character-set.

example:

  my $xml = $schema->dataToXML('/etc/config.xml');
  my ($xml, %details) = $schema->dataToXML($something);
  my $xml = XML::Compile->dataToXML('/etc/config.xml');
    

$obj->initParser(%options)

XML::Compile->initParser(%options)

Create a new parser, an XML::LibXML::Parser object. By default, the parsing is set in a safe mode, avoiding exploits. You may explicitly overrule it, especially if you need to process entities.

Administration¶

$obj->findSchemaFile($filename)

XML::Compile->findSchemaFile($filename)

Runs through all defined schema directories (see addSchemaDirs()) in search of the specified $filename. When the $filename is absolute, that will be used, and no search is needed. An "undef" is returned when the file is not found, otherwise a full path to the file is returned to the caller.

Although the file may be found, it still could be unreadible.

$obj->knownNamespace($ns|PAIRS)

XML::Compile->knownNamespace($ns|PAIRS)

If used with only one $ns, it returns the filename in the distribution (not the full path) which contains the definition.

When PAIRS of $ns-FILENAME are given, then those get defined. This is typically called during the initiation of modules, like XML::Compile::WSDL11 and XML::Compile::SOAP. The definitions are global: not related to specific instances.

The FILENAMES are relative to the directories as specified with some addSchemaDirs() call.

$obj->walkTree($node, CODE)

Walks the whole tree from $node downwards, calling the CODE reference for each $node found. When that routine returns false, the child nodes will be skipped.

Distribution collection overview¶

For end-users, the following packages are of interest (the other are support packages):

• XML::Compile::Schema

  Interpret schema elements and types: create processors for XML messages.

• XML::Compile::Cache

  Helps you administer compiled readers and writers, especially useful it there are a lot of them. Extends XML::Compile::Schema.

• XML::Compile::SOAP

  Implements the SOAP 1.1 protocol. client side.

• XML::Compile::SOAP12

  Implements the SOAP 1.2 protocol.

• XML::Compile::WSDL11

  Use SOAP with a WSDL version 1.1 communication specification file.

• XML::Compile::SOAP::Daemon

  Create a SOAP daemon, directly from a WSDL file.

• XML::Compile::Tester

  Helps you write regression tests.

• XML::Rewrite

  Clean-up XML structures: beautify, simplify, extract.

• XML::Compile::Dumper

  Enables you to save pre-compiled XML handlers, the results of any "compileClient". However, this results in huge files, so this may not be worth the effort.

Comparison¶

Where other Perl modules (like SOAP::WSDL) help you using these schemas (often with a lot of run-time XPath searches), XML::Compile takes a different approach: instead of run-time processing of the specification, it will first compile the expected structure into a pure Perl CODE reference, and then use that to process the data as often as needed.

There are many Perl modules with the same intention as this one: translate between XML and nested hashes. However, there are a few serious differences: because the schema is used here (and not by the other modules), we can validate the data. XML requires validation but quite a number of modules simply ignore that.

Next to this, data-types are formatted and processed correctly; for instance, the specification prescribes that the "Integer" data-type must accept values of at least 18 digits... not fitting in Perl's idea of longs.

XML::Compile also supports all more complex data-types like "list", "union", "substitutionGroup" (unions on complex type level), and even the nasty "any" and "anyAttribute", which is rarely the case for the other modules.