Wow,
Thanks a lot for that long and very indepth answer Richard!!
Really appreciate it - again, thx.
/Mike
[color=blue][color=green]
> >Iīve got a number of SPAN elements named "mySpan1", "mySpan2",
> >"mySpan3" etc,[/color]
>
> When you say "named" do you mean they have NAME attributes? The NAME
> attribute is not valid on SPAN elements according to the HTML 4 DTDs.
> But as the example strings conform to the requirements of an ID
> attribute and ID attributes are valid on all elements, it would make
> sense to be using an ID attribute.
>[color=green]
> >and want to set their "style.display" to "inline".[/color]
>
> The default display property of a SPAN element is "inline", but maybe
> you have pre-set them to "none" in the CSS.
>[color=green]
> > This works (only needs to work on IE5.5+):[/color]
>
> Intranet or broken by design (in the sense that there is nothing here
> that would prevent this form being implemented 100% successfully on
> every modern dynamic visual browser (and then some))? It is often
> helpful to go into the context in which you are working when asking
> questions here.
>[color=green]
> > for (var x = 1; x < 20; x++) {
> > document.all('mySpan'+x).style.display = "inline";[/color]
>
> IE blurs the distinction between objects and function when dealing with
> host objects and method. Native code method report that they or "object"
> when tested with the typeof operator and DOM elements and collections
> appear to accept property look-ups in the form of parameterised function
> calls. But the document.all collection is best thought of as an object,
> and so references to named properties of that object should use the
> standard ECMA Script (which JScript claims to be an implementation of)
> square bracket notation property accessor syntax:-
>
> document.all['mySpan'+x].style.display = "inline";
>
> It is difficult to say why IE allows parenthesise to be used in place of
> property accessors to achieve the same task. It might be an attempt to
> make scripting easier for people who don't really understand what they
> are doing (tolerate what would be errors in other, stricter,
> environments). But habitually using parentheses instead of square
> brackets when accessing DOM object properties is one of the things that
> makes IE centred script authors convinced that cross-browser scripting
> is harder than it really is. If they had just learnt to use the proper
> language feature in the first place they would find that a lot of IE
> only scripts would work on many other browsers unaltered.
>
> <URL:
http://jibbering.com/faq/#FAQ4_39 >
>[color=green]
> > }
> >
> >But I donīt know how many SPAN elements there are,[/color]
>
> Why not, where are they coming from? If they are generated by
> server-side processes then you do know how many there are and are in a
> position to tell the JScript.
>[color=green]
> >so I need to set x to a value big enough to change them all.[/color]
>
> Surly setting - x - to a "big enough" value is of no use at all. It is
> the - 20 - that decides how many elements you check, but that is
> probably what you mean. If you have a server-script generating the SPAN
> elements it should be in a position to write a value in place of that -
> 20 - based on the number of SPANs included on the page. Unless the
> JScript is in a separate static file, but even then the server script
> could create a global variable on the page that could be referred to in
> place of the - 20 - in the external file.
>[color=green]
> >This does, however, produce a error when the function
> >tries to set "style.display" on a SPAN that doesnīt exist.[/color]
>
> It would.
>[color=green]
> >So I need to check if the SPAN element does exist before I
> >try to set itīs "style.display".
> >
> >for (var x = 1; x < 20; x++) {
> >If (document.all('mySpan'+x))<--something like this (but that works ;)[/color]
>
> Apart from the parenthesised property access (which usually works on IE)
> the only reason for that not working is the initial capital "I " in
> the - if - statement. ECMA Script, being case sensitive, would take that
> as an identifier and treat the expression as an attempt to execute a
> function referred to by that identifier. Erroring because there probably
> is no - If - variable.
>
> if(document.all['mySpan'+x]){
> ... // it exists! (or at least, whatever it refers
> // to type-converts to boolean true, which should
> // be the same thing where properties of the
> // document.all collection are concerned).
> }
>[color=green]
> >document.all('mySpan'+x).style.display = "inline";
> >}
> >
> >But how do I do this? Help, anyone?[/color]
>
> Because SPAN elements should not have NAME attributes in valid HTML 4
> but can have ID attributes it would probably be best to use the ID
> attribute (if you are not already). As a result it would be possible to
> use the W3C DOM document.getElementById method to look up the reference
> to the SPAN element using that ID attribute. IE 5.0+ implements the
> getElementById method and it is a good habit to use W3C DOM methods
> where they are implemented by IE instead of equivalent IE proprietary
> features (document.all in this case). As it happens, it appears that IE
> implements getElementById so that it looks up the element in the
> document.all collection anyway, but habitually preferring the most
> widely supported method even when writing exclusively for IE makes
> writing cross-browser code easier at a later date.
>
> The "big enough" number strategy doesn't seem like a good idea at all.
> The number is going to have to be big enough to account for all possible
> numbers of SPAN elements else it will fail, and that means a loop that
> does a lot of work and achieves nothing for most of the time when there
> are only a small number of SPAN elements.
>
> It would probably be reasonable to - break - the loop as soon as the
> first 'mySpan'+x string failed to find a corresponding SPAN (assuming
> that the spans are sequentially numbered without interruptions). But
> then a - for - loop might not be the best option, probably a - while -
> loop would be better suited to the situation.
>
> var spanEl, count = 1;
> while(spanEl = document.getElementById('mySpan' + count++)){
> spanEl.style.display = 'inline';
> }
>
> - would start with "mySpan1" and keep going until it could not find
> "mySpan"+n.
>
> Richard.
>
>[/color]
