Locale::Po4a::Xml(3)					User Contributed Perl Documentation				      Locale::Po4a::Xml(3)

NAME

       Locale::Po4a::Xml - convert XML documents and derivates from/to PO files

DESCRIPTION

       The po4a (PO for anything) project goal is to ease translations (and more interestingly, the maintenance of translations) using gettext
       tools on areas where they were not expected like documentation.

       Locale::Po4a::Xml is a module to help the translation of XML documents into other [human] languages. It can also be used as a base to build
       modules for XML-based documents.

TRANSLATING WITH PO4A::XML
       This module can be used directly to handle generic XML documents.  This will extract all tag's content, and no attributes, since it's where
       the text is written in most XML based documents.

       There are some options (described in the next section) that can customize this behavior.  If this doesn't fit to your document format
       you're encouraged to write your own module derived from this, to describe your format's details.  See the section WRITING DERIVATE MODULES
       below, for the process description.

OPTIONS ACCEPTED BY THIS MODULE

       The global debug option causes this module to show the excluded strings, in order to see if it skips something important.

       These are this module's particular options:

       nostrip
	   Prevents it to strip the spaces around the extracted strings.

       wrap
	   Canonizes the string to translate, considering that whitespaces are not important, and wraps the translated document. This option can
	   be overridden by custom tag options. See the "tags" option below.

       caseinsensitive
	   It makes the tags and attributes searching to work in a case insensitive way.  If it's defined, it will treat <BooK>laNG and <BOOK>Lang
	   as <book>lang.

       includeexternal
	   When defined, external entities are included in the generated (translated) document, and for the extraction of strings.  If it's not
	   defined, you will have to translate external entities separately as independent documents.

       ontagerror
	   This option defines the behavior of the module when it encounter a invalid XML syntax (a closing tag which does not match the last
	   opening tag, or a tag's attribute without value).  It can take the following values:

	   fail
	       This is the default value.  The module will exit with an error.

	   warn
	       The module will continue, and will issue a warning.

	   silent
	       The module will continue without any warnings.

	   Be careful when using this option.  It is generally recommended to fix the input file.

       tagsonly
	   Extracts only the specified tags in the "tags" option.  Otherwise, it will extract all the tags except the ones specified.

	   Note: This option is deprecated.

       doctype
	   String that will try to match with the first line of the document's doctype (if defined). If it doesn't, a warning will indicate that
	   the document might be of a bad type.

       addlang
	   String indicating the path (e.g. <bbb><aaa>) of a tag where a lang="..." attribute shall be added. The language will be defined as the
	   basename of the PO file without any .po extension.

       tags
	   Space-separated list of tags you want to translate or skip.	By default, the specified tags will be excluded, but if you use the
	   "tagsonly" option, the specified tags will be the only ones included.  The tags must be in the form <aaa>, but you can join some
	   (<bbb><aaa>) to say that the content of the tag <aaa> will only be translated when it's into a <bbb> tag.

	   You can also specify some tag options putting some characters in front of the tag hierarchy. For example, you can put 'w' (wrap) or 'W'
	   (don't wrap) to override the default behavior specified by the global "wrap" option.

	   Example: W<chapter><title>

	   Note: This option is deprecated.  You should use the translated and untranslated options instead.

       attributes
	   Space-separated list of tag's attributes you want to translate.  You can specify the attributes by their name (for example, "lang"),
	   but you can prefix it with a tag hierarchy, to specify that this attribute will only be translated when it's into the specified tag.
	   For example: <bbb><aaa>lang specifies that the lang attribute will only be translated if it's into an <aaa> tag, and it's into a <bbb>
	   tag.

       foldattributes
	   Do not translate attributes in inline tags.	Instead, replace all attributes of a tag by po4a-id=<id>.

	   This is useful when attributes shall not be translated, as this simplifies the strings for translators, and avoids typos.

       customtag
	   Space-separated list of tags which should not be treated as tags.  These tags are treated as inline, and do not need to be closed.

       break
	   Space-separated list of tags which should break the sequence.  By default, all tags break the sequence.

	   The tags must be in the form <aaa>, but you can join some (<bbb><aaa>), if a tag (<aaa>) should only be considered when it's into
	   another tag (<bbb>).

       inline
	   Space-separated list of tags which should be treated as inline.  By default, all tags break the sequence.

	   The tags must be in the form <aaa>, but you can join some (<bbb><aaa>), if a tag (<aaa>) should only be considered when it's into
	   another tag (<bbb>).

       placeholder
	   Space-separated list of tags which should be treated as placeholders.  Placeholders do not break the sequence, but the content of
	   placeholders is translated separately.

	   The location of the placeholder in its block will be marked with a string similar to:

	     <placeholder type="footnote" id="0"/>

	   The tags must be in the form <aaa>, but you can join some (<bbb><aaa>), if a tag (<aaa>) should only be considered when it's into
	   another tag (<bbb>).

       nodefault
	   Space separated list of tags that the module should not try to set by default in any category.

       cpp Support C preprocessor directives.  When this option is set, po4a will consider preprocessor directives as paragraph separators.  This
	   is important if the XML file must be preprocessed because otherwise the directives may be inserted in the middle of lines if po4a
	   consider it belong to the current paragraph, and they won't be recognized by the preprocessor.  Note: the preprocessor directives must
	   only appear between tags (they must not break a tag).

       translated
	   Space-separated list of tags you want to translate.

	   The tags must be in the form <aaa>, but you can join some (<bbb><aaa>), if a tag (<aaa>) should only be considered when it's into
	   another tag (<bbb>).

	   You can also specify some tag options putting some characters in front of the tag hierarchy. For example, you can put 'w' (wrap) or 'W'
	   (don't wrap) to overide the default behavior specified by the global "wrap" option.

	   Example: W<chapter><title>

       untranslated
	   Space-separated list of tags you do not want to translate.

	   The tags must be in the form <aaa>, but you can join some (<bbb><aaa>), if a tag (<aaa>) should only be considered when it's into
	   another tag (<bbb>).

       defaulttranslateoption
	   The default categories for tags that are not in any of the translated, untranslated, break, inline, or placeholder.

	   This is a set of letters:

	   w   Tags should be translated and content can be re-wrapped.

	   W   Tags should be translated and content should not be re-wrapped.

	   i   Tags should be translated inline.

	   p   Tags should be translated as placeholders.

WRITING DERIVATE MODULES

   DEFINE WHAT TAGS AND ATTRIBUTES TO TRANSLATE
       The simplest customization is to define which tags and attributes you want the parser to translate.  This should be done in the initialize
       function.  First you should call the main initialize, to get the command-line options, and then, append your custom definitions to the
       options hash.  If you want to treat some new options from command line, you should define them before calling the main initialize:

	 $self->{options}{'new_option'}='';
	 $self->SUPER::initialize(%options);
	 $self->{options}{'_default_translated'}.=' <p> <head><title>';
	 $self->{options}{'attributes'}.=' <p>lang id';
	 $self->{options}{'_default_inline'}.=' <br>';
	 $self->treat_options;

       You should use the _default_inline, _default_break, _default_placeholder, _default_translated, _default_untranslated, and
       _default_attributes options in derivated modules. This allow users to override the default behavior defined in your module with command
       line options.

   OVERRIDING THE found_string FUNCTION
       Another simple step is to override the function "found_string", which receives the extracted strings from the parser, in order to translate
       them.  There you can control which strings you want to translate, and perform transformations to them before or after the translation
       itself.

       It receives the extracted text, the reference on where it was, and a hash that contains extra information to control what strings to
       translate, how to translate them and to generate the comment.

       The content of these options depends on the kind of string it is (specified in an entry of this hash):

       type="tag"
	   The found string is the content of a translatable tag. The entry "tag_options" contains the option characters in front of the tag
	   hierarchy in the module "tags" option.

       type="attribute"
	   Means that the found string is the value of a translatable attribute. The entry "attribute" has the name of the attribute.

       It must return the text that will replace the original in the translated document. Here's a basic example of this function:

	 sub found_string {
	   my ($self,$text,$ref,$options)=@_;
	   $text = $self->translate($text,$ref,"type ".$options->{'type'},
	     'wrap'=>$self->{options}{'wrap'});
	   return $text;
	 }

       There's another simple example in the new Dia module, which only filters some strings.

   MODIFYING TAG TYPES (TODO)
       This is a more complex one, but it enables a (almost) total customization.  It's based in a list of hashes, each one defining a tag type's
       behavior. The list should be sorted so that the most general tags are after the most concrete ones (sorted first by the beginning and then
       by the end keys). To define a tag type you'll have to make a hash with the following keys:

       beginning
	   Specifies the beginning of the tag, after the "<".

       end Specifies the end of the tag, before the ">".

       breaking
	   It says if this is a breaking tag class.  A non-breaking (inline) tag is one that can be taken as part of the content of another tag.
	   It can take the values false(0), true(1) or undefined.  If you leave this undefined, you'll have to define the f_breaking function
	   that will say whether a concrete tag of this class is a breaking tag or not.

       f_breaking
	   It's a function that will tell if the next tag is a breaking one or not.  It should be defined if the breaking option is not.

       f_extract
	   If you leave this key undefined, the generic extraction function will have to extract the tag itself.  It's useful for tags that can
	   have other tags or special structures in them, so that the main parser doesn't get mad.  This function receives a boolean that says if
	   the tag should be removed from the input stream or not.

       f_translate
	   This function receives the tag (in the get_string_until() format) and returns the translated tag (translated attributes or all needed
	   transformations) as a single string.

INTERNAL FUNCTIONS used to write derivated parsers
   WORKING WITH TAGS
       get_path()
	   This function returns the path to the current tag from the document's root, in the form <html><body><p>.

	   An additional array of tags (without brackets) can be passed as argument.  These path elements are added to the end of the current
	   path.

       tag_type()
	   This function returns the index from the tag_types list that fits to the next tag in the input stream, or -1 if it's at the end of the
	   input file.

       extract_tag($$)
	   This function returns the next tag from the input stream without the beginning and end, in an array form, to maintain the references
	   from the input file.  It has two parameters: the type of the tag (as returned by tag_type) and a boolean, that indicates if it should
	   be removed from the input stream.

       get_tag_name(@)
	   This function returns the name of the tag passed as an argument, in the array form returned by extract_tag.

       breaking_tag()
	   This function returns a boolean that says if the next tag in the input stream is a breaking tag or not (inline tag).  It leaves the
	   input stream intact.

       treat_tag()
	   This function translates the next tag from the input stream.  Using each tag type's custom translation functions.

       tag_in_list($@)
	   This function returns a string value that says if the first argument (a tag hierarchy) matches any of the tags from the second argument
	   (a list of tags or tag hierarchies). If it doesn't match, it returns 0. Else, it returns the matched tag's options (the characters in
	   front of the tag) or 1 (if that tag doesn't have options).

   WORKING WITH ATTRIBUTES
       treat_attributes(@)
	   This function handles the translation of the tags' attributes. It receives the tag without the beginning / end marks, and then it finds
	   the attributes, and it translates the translatable ones (specified by the module option "attributes").  This returns a plain string
	   with the translated tag.

   WORKING WITH THE MODULE OPTIONS
       treat_options()
	   This function fills the internal structures that contain the tags, attributes and inline data with the options of the module (specified
	   in the command-line or in the initialize function).

   GETTING TEXT FROM THE INPUT DOCUMENT
       get_string_until($%)
	   This function returns an array with the lines (and references) from the input document until it finds the first argument.  The second
	   argument is an options hash. Value 0 means disabled (the default) and 1, enabled.

	   The valid options are:

	   include
	       This makes the returned array to contain the searched text

	   remove
	       This removes the returned stream from the input

	   unquoted
	       This ensures that the searched text is outside any quotes

       skip_spaces(@)
	   This function receives as argument the reference to a paragraph (in the format returned by get_string_until), skips his heading spaces
	   and returns them as a simple string.

       join_lines(@)
	   This function returns a simple string with the text from the argument array (discarding the references).

STATUS OF THIS MODULE

       This module can translate tags and attributes.

TODO LIST

       DOCTYPE (ENTITIES)

       There is a minimal support for the translation of entities. They are translated as a whole, and tags are not taken into account. Multilines
       entities are not supported and entities are always rewrapped during the translation.

       MODIFY TAG TYPES FROM INHERITED MODULES (move the tag_types structure inside the $self hash?)

SEE ALSO

       Locale::Po4a::TransTractor(3pm), po4a(7)

AUTHORS

	Jordi Vilalta <jvprat@gmail.com>
	Nicolas Francois <nicolas.francois@centraliens.net>

COPYRIGHT AND LICENSE

	Copyright (c) 2004 by Jordi Vilalta  <jvprat@gmail.com>
	Copyright (c) 2008-2009 by Nicolas Francois <nicolas.francois@centraliens.net>

       This program is free software; you may redistribute it and/or modify it under the terms of GPL (see the COPYING file).

perl v5.14.2							    2012-05-17						      Locale::Po4a::Xml(3)