On 31 August 2010 19:20, kstubs <kst...@gmail.com> wrote:
> Thanks Richard for your answer on this! Question regarding this:
>
>> Object.extend(..., options || {}) // Extend the object created about
>
> Is it necessary to || {} (empty object) so as to not break the
> Object.extend in the event that options is null?
>
> Karl..
>
>
> On Aug 31, 10:19 am, Richard Quadling <rquadl...@gmail.com> wrote:
>> On 31 August 2010 17:49, kstubs <kst...@gmail.com> wrote:
>>
>>
>>
>>
>>
>> > Hello,
>> > Full credit to: Matthew Foster for the code below. I'd like an
>> > explanation of the below. I'm having some troubles with Object extend
>> > and would like a better explanation of the magic that occurs below.
>>
>> > $C = function(name, options) {
>> > return Element.extend(Object.extend(document.createElement(name ||
>> > "div"), options || {}));
>> > }
>>
>> > Sample use:
>> > var next = $C("td", { innerHTML: ">", className: "next" });
>>
>> > So how are the properties innerHTML and className morphed on to this
>> > new td element?
>>
>> > Thanks,
>> > Karl..
>>
>> Object.extend takes a set of name/value pairs and applies them to
>> whatever object it is extending.
>>
>> So, innerHTML and className, both properties of the DOM element TD,
>> get assigned by Object.extend.
>>
>> Taking the code inside out ...
>>
>> document.createElement(name || "div") // Create an element based of
>> the type defined by the value of name or a div, if no name is
>> supplied.
>> Object.extend(..., options || {}) // Extend the object created about
>> with the name/value pairs in options, or not, if no options have been
>> supplied.
>> Element.extend(...) // Same as $(...);
>>
>> Hope that helps.
>>
>> --
>> Richard Quadling
>> Twitter : EE : Zend
>> @RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY
>
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The Object.extend code doesn't validate the options. So, if null is
supplied, this would result in an 'undefined' error.
Considering that in most cases you'd be extending an object with
something, rather than simply subclassing it with no additional
properties/methods, then the code is tuned to the most common use
case.
Using 'options || {}' simply turns the code into a common form.
--
Richard Quadling
Twitter : EE : Zend
@RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY
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