SYNOPSIS
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, $b_clone);
DESCRIPTION
HTML::ElementSuper is an extension for HTML::Element(3) that provides several new methods to assist in element manipulation. An HTML::ElementSuper has the following additional properties:
* report is coordinate position in a tree of its peers
* replace its contents
* wrap its contents in a new element
* mask itself so that it and its descendants are invisible to
traverse()
* clone itself and other HTML::Element based object trees
* handle multiple values for attributes
Note that these extensions were originally developed to assist in implementing the HTML::ElementTable(3) class, but were thought to be of general enough utility to warrant their own package.
METHODS
- new('tag', attr => 'value', ...)
- Return a new HTML::ElementSuper object. Exactly like the constructor for HTML::Element(3), takes a tag type and optional attributes.
- push_attr(attr => @values)
- Extend the value string for a particular attribute. An example of this might be when you'd like to assign multiple CSS classes to a single element. The attribute value is extended using white space as a separator.
- addr()
- Returns the position of this element in relation to its siblings based on the content of the parent, starting with 0. Returns undef if this element has no parent. In other words, this returns the index of this element in the content array of the parent.
- position()
- Returns the coordinates of this element in the tree it inhabits. This is accomplished by succesively calling addr() on ancestor elements until either a) an element that does not support these methods is found, or b) there are no more parents. The resulting list is the n-dimensional coordinates of the element in the tree.
- replace_content(@new_content)
- Simple shortcut method that deletes the current contents of the element before adding the new.
- wrap_content($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''.