It shows up as "n" because the SWFObject library is compressed ("minified").
It's an automated process that gives all variables the shortest names
possible. Here's an (admittedly simplistic and silly) example
----------------------------------
function mergeStrings(first, second){
return first + second;
}
var firstvariable = "hi";
var secondvariable = "world";
var thirdvariable = mergeStrings(firstvariable, secondvariable);
----------------------------------
will be compressed to
----------------------------------
function f(){return a+b};var a="hi",b="world",c=f(a,b)
----------------------------------
As you can see, it's a substantial savings on file size but with the
trade-off of illegibility. It isn't meant to be human-readable.
If you're trying to debug what's going on in your site, you could use the *
uncompressed* version of SWFObject while you troubleshoot. It's (a bit)
easier to read and has the same functionality. :)
http://ajax.googleapis.com/ajax/libs/swfobject/2.2/swfobject_src.js
- philip
On Tue, Jan 26, 2010 at 3:37 PM, Jean <[email protected]> wrote:
> Fair enough. You have good arguments about not adding custom error
> handling. How about giving the variable a more descriptive name than
> "n"? If the variable were named "element", then the error message
> would say, "element is null", which would be an improvement.
>
> Thanks for pointing out I'm using a seriously outdated version. I'm
> looking forward to the upgrade!
>
> Jean
>
> On Jan 21, 1:43 pm, Philip Hutchison <[email protected]> wrote:
> > Hi Jean
> >
> > Thanks for the input.
> >
> > First, let me point out that you're using a really outdated version of
> > SWFObject. The current release is 2.2, which uses a completely
> re-written
> > codebase than 1.5.
> >
> > Regardless, both editions do not check for the existence of the targeted
> DOM
> > element.
> >
> > Would it be useful to add error-checking? Probably. I do this all the
> time
> > in my own scripts. However, the current practice for every major
> JavaScript
> > library/framework (jQuery, MooTools, Dojo, etc.) is to assume that
> checking
> > for the existence of the DOM element is the *page developer*'s
> > responsibility. If you don't know if your element is going to exist (and
> I
> > wonder why you wouldn't know), you can write your own check:
> >
> > var myElement = document.getElementById("flashcontent");
> > if(myElement){
> > swfobject.embedSWF("myContent.swf", "flashcontent", "300", "120",
> > "9.0.0");
> >
> > }
> >
> > Two thoughts:
> >
> > *Custom error messages
> > *You're right when you say a custom error message could potentially help
> a
> > developer debug their code. However, there are many issues that would
> arise
> > from trying to introduce custom error code, including the size of our
> > codebase (which needs to be as small as possible), and the method of
> > delivering the message (not everyone has access to console.log via
> Firebug
> > or Safari).
> >
> > *Silent failure*
> > Another possibility is silent failure. The code could be edited to
> simply
> > exit and not do anything if the DOM element is not found. This could
> > potentially make debugging even more difficult (why isn't my SWF showing
> up?
> > what's going on?) and creates a more lax coding environment. It's better
> to
> > allow the error to go through so the developer knows there's something
> > wrong.
> >
> > As for the cryptic error messages you currently see, they're up to the
> > browser. Different browsers show different errors. But the "n is
> undefined"
> > or "n is null" type errors are very well documented in this Google Group
> > support list.
> >
> > - philip
> >
> > On Thu, Jan 21, 2010 at 8:06 AM, Jean <[email protected]> wrote:
> > > Hi, I recently discovered that if the element I pass in for the
> > > SWFObject to be written into is null, the error I get back is "n is
> > > null", which had me befuddled for a little while. I figured out what
> > > was wrong because Firebug showed me the relevant lines of code, but it
> > > seems that the error message could be changed to be something more
> > > descriptive, like "element not found: div_flashGoesHere_typo".
> >
> > > Example of my code:
> > > var so = new SWFObject("usindexesview.swf", "usindexesview", "1000",
> > > "450", "9", "#eeeeee");
> > > so.write('div_flashGoesHere_typo');
> >
> > > My page does have a div element called 'div_flashGoesHere' but not one
> > > called 'div_flashGoesHere_typo'. The error comes on these lines in
> > > swfobject.js:
> >
> > > 125 var n = (typeof elementId == 'string') ?
> > > document.getElementById(elementId) : elementId;
> > > 126 n.innerHTML = this.getSWFHTML();
> >
> > > So the error I get is "n is null", which happens on line 126.
> >
> > > At the very least, it would help if the variable were renamed
> > > 'element' or something more descriptive than 'n', but I leave the
> > > implementation details up to you. :-)
> >
> > > Thanks for making a great little script! I'm just hoping I can help
> > > make it a bit better.
> >
> > > Jean
> >
> > > --
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> <swfobject%[email protected]<swfobject%[email protected]>
> >
> > > .
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>
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