HTML::ElementSuper - Perl extension for HTML::Element(3)
use HTML::ElementSuper;
### Positional extension
$e = new HTML::ElementSuper 'font';
$sibling_number = $e->addr();
$e2 = new HTML::ElementSuper 'p';
$e2->push_content($e);
#
@coords = $e->position();
$depth_in_pos_tree = $e->depth();
### Replacer extension
$er = new HTML::ElementSuper 'font';
# Tree beneath $er, if present, is dropped.
$er->replace_content(new HTML::Element 'p');
### Wrapper extension
$ew = new HTML::ElementSuper;
$ew->push_content("Tickle me, baby");
$ew->wrap_content(new HTML::Element 'font', color => 'pink');
print $ew->as_HTML();
### Maskable extension
$em = new HTML::ElementSuper 'td';
$em->mask(1);
print $em->as_HTML; # nada
$em->mask(0);
print $em->as_HTML; # $e and its children are visible
### Cloning of own tree or another element's tree
### (is this the correct clomenature? :-)
$a = new HTML::ElementSuper 'font', size => 2;
$b = new HTML::ElementSuper 'font', color => 'red';
$a_clone = $a->clone;
$b_clone = $a->clone($b);
# Multiple elements can be cloned
@clone_clones = $a_clone->clone($a_clone, $b_clone);
HTML::ElementSuper is an extension for HTML::Element(3) that provides
several new methods to assist in element manipulation. An HTML::ElementSuper
has the following additional properties:
* report is coordinate position in a tree of its peers
* replace its contents
* wrap its contents in a new element
* mask itself so that it and its descendants are invisible to
traverse()
* clone itself and other HTML::Element based object trees
* handle multiple values for attributes
Note that these extensions were originally developed to assist in
implementing the HTML::ElementTable(3) class, but were thought to be
of general enough utility to warrant their own package.
- new('tag', attr => 'value', ...)
- Return a new HTML::ElementSuper object. Exactly like the constructor for
HTML::Element(3), takes a tag type and optional attributes.
- push_attr(attr => @values)
- Extend the value string for a particular attribute. An example of this
might be when you'd like to assign multiple CSS classes to a single
element. The attribute value is extended using white space as a
separator.
- addr()
- Returns the position of this element in relation to its siblings based on
the content of the parent, starting with 0. Returns undef if this element
has no parent. In other words, this returns the index of this element in
the content array of the parent.
- position()
- Returns the coordinates of this element in the tree it inhabits. This is
accomplished by succesively calling addr() on ancestor elements
until either a) an element that does not support these methods is found,
or b) there are no more parents. The resulting list is the n-dimensional
coordinates of the element in the tree.
- replace_content(@new_content)
- Simple shortcut method that deletes the current contents of the element
before adding the new.
- wrap_content($wrapper_element)
- Wraps the existing content in the provided element. If the provided
element happens to be a non-element, a push_content is performed
instead.
- mask
- mask(mode)
- Toggles whether or not this element is visible to parental methods that
visit the element tree using traverse(), such as as_HTML().
Valid arguments for mask() are 0 and 1. Returns the current setting
without an argument.
This might seem like a strange method to have, but it helps in
managing dynamic tree structures. For example, in
HTML::ElementTable(3), when you expand a table cell you simply
mask what it covers rather than destroy it. Shrinking the table cell
reveals that content to as_HTML() once again.
- clone
- clone(@elements)
- Returns a clone of elements and all of their descendants. Without
arguments, the element clones itself, otherwise it clones the elements
provided as arguments. Any element can be cloned as long as it is
HTML::Element(3) based. This method is very handy for duplicating
tree structures since an HTML::Element cannot have more than one parent at
any given time...hence "tree".
HTML::Element(3), Data::Dumper(3)
Matthew P. Sisk, <sisk@mojotoad.com>
Copyright (c) 1998-2010 Matthew P. Sisk. All rights reserved. All wrongs
revenged. This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
HTML::Element(3), HTML::ElementGlob(3),
HTML::ElementRaw(3), HTML::ElementTable(3), perl(1).