XML::LibXML::PI(3) User Contributed Perl Documentation XML::LibXML::PI(3)

# [NAME](#NAME)

XML::LibXML::PI - XML::LibXML Processing Instructions

# [SYNOPSIS](#SYNOPSIS)

```
  use XML::LibXML;
  # Only methods specific to Processing Instruction nodes are listed here,
  # see the XML::LibXML::Node manpage for other methods
  $pinode->setData( $data_string );
  $pinode->setData( name=>string_value [...] );
```

# [DESCRIPTION](#DESCRIPTION)

Processing instructions are implemented with XML::LibXML with read and write access. The PI data is the PI without the PI target (as specified in XML 1.0 \[17]) as a string. This string can be accessed with getData as implemented in XML::LibXML::Node.

The write access is aware about the fact, that many processing instructions have attribute like data. Therefore **setData()** provides besides the DOM spec conform Interface to pass a set of named parameter. So the code segment

```
  my $pi = $dom->createProcessingInstruction("abc");
  $pi->setData(foo=>'bar', foobar=>'foobar');
  $dom->appendChild( $pi );
```

will result the following PI in the DOM:

```
  <?abc foo="bar" foobar="foobar"?>
```

Which is how it is specified in the DOM specification. This three step interface creates temporary a node in perl space. This can be avoided while using the **insertProcessingInstruction()** method. Instead of the three calls described above, the call

```
  $dom->insertProcessingInstruction("abc",'foo="bar" foobar="foobar"');
```

will have the same result as above.

XML::LibXML::PI's implementation of **setData()** documented below differs a bit from the standard version as available in XML::LibXML::Node:

[setData](#setData)

```
  $pinode->setData( $data_string );
  $pinode->setData( name=>string_value [...] );
    
```

This method allows one to change the content data of a PI. Additionally to the interface specified for DOM Level2, the method provides a named parameter interface to set the data. This parameter list is converted into a string before it is appended to the PI.

# [AUTHORS](#AUTHORS)

Matt Sergeant, Christian Glahn, Petr Pajas

# [VERSION](#VERSION)

2.0212

# [COPYRIGHT](#COPYRIGHT)

2001-2007, AxKit.com Ltd.

2002-2006, Christian Glahn.

2006-2009, Petr Pajas.

# [LICENSE](#LICENSE)

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2026-10-30 perl v5.44.0

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Document: XML::LibXML::PI(3pm) from perl-xml-libxml 2.0212-r4 (Chainguard OS)
Source: https://github.com/shlomif/perl-XML-LibXML