Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
Reindent(3)	      User Contributed Perl Documentation	   Reindent(3)

NAME
       XML::Filter::Reindent - Reformats whitespace for	pretty printing	XML

SYNOPSIS
	use XML::Handler::Composer;
	use XML::Filter::Reindent;

	my $composer = new XML::Handler::Composer (%OPTIONS);
	my $indent = new XML::Filter::Reindent (Handler	=> $composer, %OPTIONS);

DESCRIPTION
       XML::Filter::Reindent is	a sub class of XML::Filter::DetectWS.

       XML::Filter::Reindent can be used as a PerlSAX filter to	reformat an
       XML document before sending it to a PerlSAX handler that	prints it
       (like XML::Handler::Composer.)

       Like XML::Filter::DetectWS, it detects ignorable	whitespace and blocks
       of whitespace characters	in certain places. It uses this	information
       and information supplied	by the user to determine where whitespace may
       be modified, deleted or inserted.  Based	on the indent settings,	it
       then modifies, inserts and deletes characters and ignorable_whitespace
       events accordingly.

       This is just a first stab at the	implementation.	 It may	be buggy and
       may change completely!

Constructor Options
       o   Handler

	   The PerlSAX handler (or filter) that	will receive the PerlSAX
	   events from this filter.

       o   Tab (Default: one space)

	   The number of spaces	per indent level for elements etc. in document
	   content.

       o   Newline (Default: "\x0A")

	   The newline to use when re-indenting.  The default is the internal
	   newline used	by XML::Parser,	XML::DOM etc., and should be fine when
	   used	in combination with XML::Handler::Composer.

$self->indent_children ($start_element_event)
       This method determines whether children of a certain element may	be
       reformatted.  The default implementation	checks the PreserveWS
       parameter of the	specified start_element	event and returns 0 if it is
       set or MAYBE otherwise.	The value MAYBE	\fIs0(2) indicates that
       further investigation is	needed,	e.g.  by examining the element
       contents. A value of 1 means yes, indent	the child nodes, no further
       investigation is	needed.

       NOTE: the PreserveWS parameter is set by	the parent class,
       XML::Filter::DetectWS, when the element or one of its ancestors has the
       attribute xml:space="preserve".

       Override	this method to tweak the behavior of this class.

$self->indent_element ($start_element_event, $parent_says_indent)
       This method determines whether a	certain	element	may be re-indented.
       The default implementation returns the value of the $parent_says_indent
       parameter, which	was set	to the value returned by indent_children for
       the parent element. In other words, the element will be re-indented if
       the parent element allows it.

       Override	this method to tweak the behavior of this class.  I'm not sure
       how useful this hook is.	Please provide feedback!

Current	Implementation
       The current implementation puts all incoming Perl SAX events in a queue
       for further processing. When determining	which nodes should be re-
       indented, it sometimes needs information	from previous events, hence
       the use of the queue.

       The parameter (Compress => 1) is	added to matching start_element	and
       end_element events with no events in between This indicates to an XML
       printer that a compressed notation can be used, e.g <foo/>.

       If an element allows reformatting of its	contents (xml:space="preserve"
       was not active and indent_children returned MAYBE), the element
       contents	will be	reformatted unless it only has one child node and that
       child is	a regular text node (characters	event.)	 In that case, the
       element will be printed as <foo>text contents</foo>.

       If you want element nodes with just one text child to be	reindented as
       well, simply override indent_children to	return 1 instead of MAYBE (2.)

       This behavior may be changed or extended	in the future.

CAVEATS
       This code is highly experimental!  It has not been tested well and the
       API may change.

       The code	that detects blocks of whitespace at potential indent
       positions may need some work.

AUTHOR
       Original	Author is Enno Derksen.

       Send bug	reports, hints,	tips, suggestions to T.J. Mather at
       <tjmather@tjmather.com>.

perl v5.24.1			  2002-04-06			   Reindent(3)

NAME | SYNOPSIS | DESCRIPTION | Constructor Options | $self->indent_children ($start_element_event) | $self->indent_element ($start_element_event, $parent_says_indent) | Current Implementation | CAVEATS | AUTHOR

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=XML::Filter::Reindent&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help