Tutorial Addendum on Perl - Allotment B - XML::Simple Bore

This affiliate describes:

    

    
• Introduction to XML::Simple module.
  
      



    
• Example Perl programs to use XML::Simple options.
  
      



    
• Example Perl program to adapt the parsed XML hash.
  
      



    

If you charge to understand added about XML, amuse apprehend my additional book:

    

" s Addendum on XML Technologies".

    

XML::Simple Methods

    

XML::Simple bore is an simple API to apprehend and address XML files. It offers two capital methods:

    

XMLin() and XMLout().

    

XMLin(str) - Adjustment to anatomize the XML ascribe into a hash, and acknowledgment the advertence of the hash.

    

The XML ascribe can be defined in 3 ways:

    

    
• If the adjustment is alleged with no parameter, the XML ascribe is in script_name.xml, where
  
      

  script_name is the aforementioned name of the calling Perl Software file.



    
• If the adjustment is alleged with a cord constant absolute <tag>, the XML ascribe is the cord param.


    
• If the adjustment is alleged with a cord constant after any <tag>, the XML ascribe is in
  
      

  the book with the cord param as book name.



    

XMLout(ref) - Adjustment to address the assortment acicular by the defined advertence into an XML string,

    

and acknowledgment XML string.

    

Here is a simple program to appearance you how to use XML:Simple:

    

 

    
#- XmlSimpleHello.pl

    
#- Absorb (c) 1999 by Dr.  Yang

    
#

    
   use XML::Simple;

    
   my $xs = new XML::Simple();

    
   my $ref = $xs->XMLin("<p>Hello world!</p>");

    
   my $xml = $xs->XMLout($ref);

    
   book $xml;

    
   exit;

    

Output:

    

 

    
<opt>Hello world!</opt>

    

It s absorbing to see from the achievement that the <p> tag has been changed

    

to <opt> during the apprehend and address operations. This is because of the absence

    

setting of the option: keeproot. I will explain some of the important options later

    

in this chapter.

    

XML::Simple Options

    

XML::Simple options can be defined in the new() adjustment call:

    

 

    
   $xs = new XML::Simple(option1 => value, option2 => value, ...);

    

Commonly acclimated options are:

    

1. keeproot => 1: Applies to both XMLin() and XMLout() to accumulate the basis tag.

    

2. searchpath => list: Applies to XMLin() to specifies the directories to search

    

for ascribe XML files.

    

3. forcearray => 1: Applies to XMLin() to force the capacity of all elements to

    

be an array.

    

4. suppressempty => 1 or : Applies to XMLin() to skip abandoned elements or

    

to represent them as strings. The absence behavior is to represent abandoned elements

    

as references of abandoned hashes. The absence behavior makes it harder to admission

    

empty elements in the parsed hash.

    

5. keyattr => list: Applies to XMLin() and XMLout() to name attributes,

    

or sub-elements as keys to be acclimated to promot the ancestor aspect from

    

array to hash. Bethink that there is absence list: "name", "key", and "id".