NAME

GvaScript.protoExtensions - Extensions to prototype.js

SYNOPSIS

  Element.hasAnyClass(elem, ["class1", "class2", ...]);  
  Element.getElementsByClassNames(elem, ["class1", "class2", ...]);  

  var stop_condition = function(elem) { return elem.tagName == "SPAN"};
  Element.navigateDom(elem, "nextSibling", ["class1", "class2", ...],
                       stop_condition);

  this.options = Class.checkOptions(defaultOptions, receivedOptions);

DESCRIPTION

Some extensions to the basic abstractions supplied by prototype.js.

METHODS

Element extensions

hasAnyClass

  if (Element.hasAnyClass(elem, ["class1", "class2", ...]) {...}  

  if (Element.hasAnyClass(elem, "class1") {...}  

Returns true if the supplied element has any of the given classes. For convenience, also accepts a single string instead of an array when testing for a single class.

getElementsByClassNames

  var subElements 
     = Element.getElementsByClassNames(rootElement, ["class1", "class2", ...]);

Returns an array of children of rootElement that have any of the given class names.

navigateDom

  var wantedClasses = ["class1", "class2", ...];
  
  // which direction to navigate (could be "parentNode", etc.)
  var direction     = "nextSibling"; 

  // some criteria for stopping navigation (can be anything, here a stupid
  // example)
  var stopCondition = function(elem) {return elem.innerHTML.length > 10}

  var nextElement
    = Element.navigateDom(startElement, direction, wantedClasses,
                          stopCondition);

Walks through the DOM in the given direction, until finding an element that has one of the given classnames, or finding a stop condition (in which case null is returned).

autoScroll

  Element.autoScroll(elem, percentage) 

Makes sure that elem is visible in the central area of its offset parent; if not, the parent is scrolled. percentage is the ratio between the parent height and the margin at which scrolling must occur, i.e. if percentage = 20 (the default), then scrolling occurs if the element is in the higher than the top 20% or lower than the bottom 20% of the viewport.

Element extensions

detailedStop

  Event.detailedStop(event, toStop);

Browser-independent method to control fine details of event stopping within event handlers. The toStop argument is an object which may contain the following properties:

stopPropagation

if true, the event will not be passed to further handlers up the bubbling hierarchy.

preventDefault

if true, the default behaviour of the browser for that event will be cancelled

stopAll

Just a convenience object, having both properties above set to true. So

  Event.detailedStop(event, Event.stopAll);

is equivalent to calling prototype's Event.stop(event).

Class extensions

checkOptions

  this.options = Class.checkOptions(defaultOptions, ctorOptions)

Utility for constructor methods. The first argument is an object containing a collection of default options (keys and values). The second argument is a similar object, containing options given to the constructor.

If one of the keys in ctorOptions has no corresponding key in defaultOptions, an error is generated (because the constructor does not expect such a key). Otherwise, the concatenation of both objects is returned (i.e. values in ctorOptions take precedence over values in defaultOptions).

ASSERT

  ASSERT (cond, msg);

Checks if cond is true, and if not, generates an error with message msg.

cpanm Alien::GvaScript

perl -MCPAN -e shell
install Alien::GvaScript