code embedded in html file vs .js file reference

**Michael Winter** · Jul 20 '05, 03:02 PM

Re: code embedded in html file vs .js file reference

On Sun, 07 Mar 2004 08:05:27 GMT, comcast news <bxtrap01@comca st.net>
wrote:
[color=blue]
> at least i think it this is the problem
> am trying to fix a webpage/javascript that i didn't write
> www.deltaneutral.com when invoked or any new page from the menu, get
> the
> error msg
> line 2
> char 1
> syntax error
> code 0
> there is a java scipt file invoked early on that 'seems' to be the
> problem,
> its just after the body tag
> <script language=javasc ript src=/scripts/swap.js></script>
> the code is at the end of this post
> however, when i embed the code directly in the page, instead of the file
> reference, the error goes away
> and the functions seem to execute ok
> i have checked the .js file with a hex editor looking for hidden weird
> bytes
> but havent' found any
> that look out of the ordinary, so i'm stumped why the seemingly same
> code
> gets the error msg
> only when it is invoked via its .js file
> also i have loaded the html and .js file on a different, 2nd web server
> just
> to be sure that somehow
> the primary server isn't somehow supplying the .js file with a funny byte
>
>
>
> <script type="text/javascript">
> //alert ("now entering swap2ansi");
> function WM_imageSwap(da Image, offOn){
> var daPath = "images/";
> var daPage = "home";
> // Check to make sure that images are supported in the DOM.
> if(document.ima ges){
> // Check to see whether you are using a name, number, or object
> if (typeof(daImage ) == 'string') {
> // This whole objStr nonesense is here solely to gain
> compatability
> // with ie3 for the mac.
>
> objStr = 'document.' + daImage;
> obj = eval(objStr);
> srcStr = daPath + "nav_" + daImage + "_" + offOn + ".gif";
> //srcEval = eval(daPath);
> obj.src = srcStr;
>
> objStr2 = 'document.' + daPage;
> obj2 = eval(objStr2);
>
> if (offOn == "on") {
> srcStr2 = daPath + "nav_" + daPage + "_off.gif";
> obj2.src = srcStr2;
> } else {
> srcStr2 = daPath + "nav_" + daPage + "_on.gif";
> obj2.src = srcStr2;
> }
>
> } else if ((typeof(daImag e) == 'object') && daImage && daImage.src)
> {
>
> daImage.src = daPath + "nav_" + daImage + "_" + offOn + ".gif";
> if (offOn == "on") {
> daPage.src = daPath + "nav_" + daPage + "_off.gif";
> } else {
> daPage.src = daPath + "nav_" + daPage + "_on.gif";
> }
> }
> }
> }
>
>
> function SimpleSwap(daIm age, daSrc){
> var objStr,obj;
> //alert ("now entering simple swap");
> // Check to make sure that images are supported in the DOM.
> if(document.ima ges){
> // Check to see whether you are using a name, number, or object
> if (typeof(daImage ) == 'string') {
> // This whole objStr nonesense is here solely to gain
> compatability
> // with ie3 for the mac.
> objStr = 'document.' + daImage;
> obj = eval(objStr);
> obj.src = daSrc;
> } else if ((typeof(daImag e) == 'object') && daImage && daImage.src)
> {
> daImage.src = daSrc;
> }
> }
> }
> //
> </script>
>
>
>[/color]

--
Michael Winter
M.Winter@blueyo nder.co.invalid (replace ".invalid" with ".uk" to reply)

**Michael Winter** · Jul 20 '05, 03:02 PM

Re: code embedded in html file vs .js file reference

On Sun, 07 Mar 2004 08:05:27 GMT, comcast news <bxtrap01@comca st.net>
wrote:

[snip]
[color=blue]
> its just after the body tag
> <script language=javasc ript src=/scripts/swap.js></script>[/color]

If this is the exact tag pair, the problem is that the src attribute value
is not quoted. Quotes *must* be used when the value includes characters
that are not among this set:

- Letters
- Numbers
- Underscores (_)
- Periods (.)
- Hyphens (-)
- Colons (:)

Furthermore, the type attribute is required for the script element, and
the language attribute is deprecated. The above should read:

<script type="text/javascript" src="/scripts/swap.js"></script>

You could also place it in the HEAD element so that it is guaranteed to be
available to the document.

[snip]

The script below contains unnecessary eval() function calls. You should
modify the code with the alternatives that I show below (comments have
been stripped for clarity).
[color=blue]
> <script type="text/javascript">
> function WM_imageSwap(da Image, offOn){
> var daPath = "images/";
> var daPage = "home";
> if(document.ima ges){
> if (typeof(daImage ) == 'string') {
>
> objStr = 'document.' + daImage;
> obj = eval(objStr);[/color]

daImage is a string that contains the name or id of an IMG element,
correct? If so, it should be accessed using the images collection:

obj = document.images[ daImage ];

For future reference, you could have avoided the eval() call using:

obj = document[ daImage ];

If daImage was 'logo', for example, it would be the same as writing:

obj = document.logo;
[color=blue]
> srcStr = daPath + "nav_" + daImage + "_" + offOn + ".gif";
> //srcEval = eval(daPath);[/color]

Image.src expects a string, so that eval() should never have been
necessary. The assignment might as well be direct, too: the value isn't
used elsewhere, so the variable is unnecessary.

Both of intermediate variables (objStr and srcStr) have been declared
global unnecessarily. Use the var keyword to keep them local.
[color=blue]
> obj.src = srcStr;
>
> objStr2 = 'document.' + daPage;
> obj2 = eval(objStr2);[/color]

This should probably be:

obj2 = document.images[ daPage ];

and if not, it should certainly be:

obj2 = document[ daPage ];

[snipped object branch]
[color=blue]
> function SimpleSwap(daIm age, daSrc){
> var objStr,obj;
> if(document.ima ges){
> if (typeof(daImage ) == 'string') {
> objStr = 'document.' + daImage;
> obj = eval(objStr);[/color]

I'm sure you can guess by now how this should be written.
[color=blue]
> obj.src = daSrc;
> } else if ((typeof(daImag e) == 'object') && daImage && daImage.src)
> {
> daImage.src = daSrc;
> }
> }
> }
> //[/color]

Informative comment! :P
[color=blue]
> </script>[/color]

Hope that helps,
Mike

--
Michael Winter
M.Winter@blueyo nder.co.invalid (replace ".invalid" with ".uk" to reply)

**David Dorward** · Jul 20 '05, 03:02 PM

Re: code embedded in html file vs .js file reference

comcast news wrote:
[color=blue]
> at least i think it this is the problem
> am trying to fix a webpage/javascript that i didn't write
> www.deltaneutral.com when invoked or any new page from the menu, get
> the error msg[/color]

..js files should contain JavaScript, not a combination of HTML and
JavaScript.

Get rid of the <script> tags from .js files.

(and run the HTML through http://validator.w3.org/ )

--
David Dorward <http://dorward.me.uk/>

**Richard Cornford** · Jul 20 '05, 03:02 PM

Re: code embedded in html file vs .js file reference

Michael Winter wrote: <opr4hk9cxa5vkl cq@news-text.blueyonder .co.uk>
<snip>[color=blue][color=green]
>> <script type="text/javascript">
>> function WM_imageSwap(da Image, offOn){[/color][/color]
<snip>

There are two other common causes of javascript moved to external files
not working in that location when they work form a page. The first is
including HTML in the external file, so if that opening script tag is in
the external file it becomes a syntax error because it is not
javascript. (SGML comment tags are also often syntax errors in external
JS files)

The other is badly configured servers, specifically older apache
versions where files with JS extensions are not associated with a known
content type so the server sends them as text/html (which doesn't matter
in itself) but also inserts an HTML 2.0 doctype, which is again a syntax
error in a javascript file. You don't see this second problem much these
days.

In both cases testing with Mozilla/Gecko browsers usually reveals the
problem as its error messages include the offending line of code, so it
is obvious when it is not javascript (or was not part of the original
file).

Richard.

code embedded in html file vs .js file reference

code embedded in html file vs .js file reference

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