Preloading images?

[Jim Ley]

Re: Preloading images?

On Sat, 25 Oct 2003 19:49:36 +0200, Thomas 'PointedEars' Lahn
<PointedEars@we b.de> wrote:
[color=blue]
>Jim Ley wrote:[color=green]
>> So why suggest that other people stop using preloading,[/color]
>
>I have only suggested that they think about it before using it.[/color]

That is not what you said in this thread.
[color=blue]
>That may be OK to you, but who of us is now imposing behaviors on others
>here when you write that it is therefore also OK to others?[/color]

Neither of us... All web authoring is suggesting, suggesting
something be preloaded can be important for usability, telling people
not to do is it is not helpful.
[color=blue]
>Since users pay for downloaded data as well as connection time I doubt
>they would appreciate it if their download or connection time quota is
>spoiled by downloading (a bunch of navigational) images they do not want
>because they do not need them (and vice-versa.)[/color]

Where did I say anything about using images for navigation - that's
most certainly a really bad idea, and I can fully agree with you that
it is bad - but what's that got to do with preloading images, other
than the fact some people misuse it in that way?

Jim.
--
comp.lang.javas cript FAQ - http://jibbering.com/faq/

[Stephen]

Re: Preloading images?

Thomas 'PointedEars' Lahn wrote:
[color=blue]
> Stephen wrote:
>
> [...snip...][/color]
[color=blue][color=green]
>>
>>I do not believe the user's browser cache settings have anything to do
>>with whether the images "preload"[/color]
>
>
> But they actually have.[/color]

Actually, I stand by the statement I made, where "preload" is doing what
the OP originally wrote about:

var preload1 = new Image(); preload1.src = "/pic/yay.gif";
var preload2 = new Image(); preload2.src = "/pic/nay.gif";

This is based on my observations and is not simply an assertion.
[color=blue]
> What achieved by preloading is only that there is an
> Image object created and a resource is accessed by a HTTP request (if not on
> the local file system.)[/color]

Pretty much ok, but for that "file system" part. The term "cache" is
really a bit ambiguous: there is disk cache and memory cache. So the
browser uses memory for storing some of its "stuff" -- and it is into
memory that the "preloaded" images go; they may also get stored in disk
cache. Even if I turn off disk caching the memory part still works. By
my observation, this even works in Opera, where one can explicitly "turn
off" memory caching.
[color=blue]
> That resource is saved in the cache and therefore
> need not to be downloaded a second time if, and only if, it is then still in
> the cache, which speeds up the display.[/color]

It is being in memory that makes rollovers work really fast. Even
fetching a (disk)-cached copy could be too long. The point is to make
rollovers appear instantaneous.

Again, I do not believe there is any user browser cache setting that has
anything to do with whether the images "preload".

Of course, a clear, unambiguous example illustrating a user setting for
browser cache that causes "preloads" to fail could change my mind on the
matter.

Regards,
Stephen

[Fabian]

Re: Preloading images?


"Thomas 'PointedEars' Lahn" <PointedEars@we b.de> wrote in message
[color=blue]
> Since users pay for downloaded data as well as connection time I doubt
> they would appreciate it if their download or connection time quota is
> spoiled by downloading (a bunch of navigational) images they do not[/color]
want[color=blue]
> because they do not need them (and vice-versa.) Multimedia experience[/color]
is[color=blue]
> not everything, sometimes you are just looking for useful information.[/color]

For Japanese schholchildren, my target audience, multimedia is king. A
plain text site would have them fall asleep in seconds.


--
--
Fabian
Visit my website often and for long periods!

http://www.lajzar.co.uk

[Thomas 'PointedEars' Lahn]

Re: Preloading images?

Fabian wrote:
[color=blue]
> "Thomas 'PointedEars' Lahn" <PointedEars@we b.de> wrote in message[color=green]
>> Since users pay for downloaded data as well as connection time I doubt
>> they would appreciate it if their download or connection time quota is
>> spoiled by downloading (a bunch of navigational) images they do not[/color]
> want[color=green]
>> because they do not need them (and vice-versa.) Multimedia experience[/color]
> is[color=green]
>> not everything, sometimes you are just looking for useful information.[/color]
>
> For Japanese schholchildren, my target audience, multimedia is king. A
> plain text site would have them fall asleep in seconds.[/color]

Read again. I did not write that you must discard images.


HTH

PointedEars

P.S.:
Your comb-like quoting (correct translation?) sucks. Alas I do not know
a non-German tutorial/FAQ for Outlook Express (Google should provide one)
but I suggest you use MorVer or OE-Tools to avoid that in the future as
many people have before.

[Fabian]

Re: Preloading images?


"Thomas 'PointedEars' Lahn" <PointedEars@we b.de> wrote in message
[color=blue]
> P.S.:
> Your comb-like quoting (correct translation?) sucks. Alas I do not[/color]
know[color=blue]
> a non-German tutorial/FAQ for Outlook Express (Google should provide[/color]
one)[color=blue]
> but I suggest you use MorVer or OE-Tools to avoid that in the future[/color]
as[color=blue]
> many people have before.[/color]

As I have no idea what comb-like quoting is, and as you are the first
person ever to comment unfavourably on my quoting style, I think I shall
pass on changing my modus operandi.


--
--
Fabian
Visit my website often and for long periods!

http://www.lajzar.co.uk

[Thomas 'PointedEars' Lahn]

Re: Preloading images?

Fabian wrote:
[color=blue]
> "Thomas 'PointedEars' Lahn" <PointedEars@we b.de> wrote in message[color=green]
>> P.S.:
>> Your comb-like quoting (correct translation?) sucks. Alas I do not[/color]
> know[/color]
^^[color=blue][color=green]
>> a non-German tutorial/FAQ for Outlook Express (Google should provide[/color]
> one)[/color]
^^[color=blue][color=green]
>> but I suggest you use MorVer or OE-Tools to avoid that in the future[/color]
> as[/color]
^^[color=blue][color=green]
>> many people have before.[/color]
>
> As I have no idea what comb-like quoting is,[/color]

I have marked it for you here.
[color=blue]
> and as you are the first person ever to comment unfavourably on my
> quoting style,[/color]

There is a first time for everything. [psf 3.3]
[color=blue]
> I think I shall pass on changing my modus operandi.[/color]

I did what you should have done and used Google before posting:

http://flash.to/oe-quotefix/

HTH & F'up2 poster

PointedEars
--
How do I quote correctly in Usenet?

http://www.netmeister.org/news/learn2quote.html

[Fabian]

Re: Preloading images?


"Thomas 'PointedEars' Lahn" <PointedEars@we b.de> wrote in message
[color=blue][color=green][color=darkred]
> >> but I suggest you use MorVer or OE-Tools to avoid that in the[/color][/color][/color]
future[color=blue][color=green]
> > as[/color]
> ^^[color=green][color=darkred]
> >> many people have before.[/color]
> >
> > As I have no idea what comb-like quoting is,[/color]
>
> I have marked it for you here.[/color]

We call that broken quotes, or wrapped quotes. Take your pick.
[color=blue][color=green]
> > I think I shall pass on changing my modus operandi.[/color]
>
> I did what you should have done and used Google before posting:[/color]

Why do you say I should have done it? Why am I under some kind of
obligation? I am following teh standards by setting the line wrap length
at 72 characters. The question is, why aren't you, and presumably, that
program, following that standard?
[color=blue]
> http://flash.to/oe-quotefix/[/color]

Ah, I see what you're talking about now. I shan't be downloading that
program. You see, while it may well appear that I am using msoe, I am in
fact using a custom news reader that I wrote myself, which creates the
headers to mimic msoe as a stealth move. I would be surprised if this
program of yours is compatible.

Either that or:

I have no desire to install additional programs on my computer, no
matter how inobtrusive they may appear. It appears this program could
manipulate my text when I post some code for example, which would not be
what I want.

Either that or:

Every newsreader (since about 1973 or so anyway) has an option to set
the line length at which it automatically wraps text, and this accepts a
value of 80 or less (for backwards compatibility with text only
readers). Every group I have ever seen recomends setting this value to
72, which will allow 4 levels of quoting before any quoting gets broken.
This is in fact the default in msoe iirc. It is certainly the current
setting on my machine (just checked), and I dont recall ever changing
it. So if my quoting gets broken after a single level of quotes, the
fault lies with the previous poster for not following the standard, not
with me.

Take your pick.

[posted, not emailed, to save bandwidth. You do read the group, dont
you? No need to set headers to force an email reply too.]

--
--
Fabian
Visit my website often and for long periods!

http://www.lajzar.co.uk

[Lasse Reichstein Nielsen]

Re: Preloading images?

"Fabian" <lajzar@hotmail .com> writes:
[color=blue]
> We call that broken quotes, or wrapped quotes. Take your pick.[/color]

I'd say "broken".
[color=blue]
> Every newsreader (since about 1973 or so anyway) has an option to set
> the line length at which it automatically wraps text, and this accepts a
> value of 80 or less (for backwards compatibility with text only
> readers).[/color]

There is definitly disagreement there. I recommend *never* to wrap
automatically. Especially in programming groups, braking lines
automatically is downright dangerous.

If you do break lines, either reflow the paragraph or retain the
quoting level on all of the broken lines. Broken quotes are just that:
broken. They incorrectly attribute every other line to the wrong
author.
[color=blue]
> Every group I have ever seen recomends setting this value to
> 72,[/color]

The recommendation is to not write lines longer than 72 characters,
not to break other people's lines where they are not meant to be
broken.
[color=blue]
> which will allow 4 levels of quoting before any quoting gets broken.[/color]

Not breaking lines will not break any quotes. It will give excessively
long lines, but some times that is necessary. Alternatively, you can
reflow the paragraph.
[color=blue]
> This is in fact the default in msoe iirc.[/color]

Probably. Having a widely used program have such bad defaults is still
bad.
[color=blue]
> It is certainly the current setting on my machine (just checked),
> and I dont recall ever changing it. So if my quoting gets broken
> after a single level of quotes, the fault lies with the previous
> poster for not following the standard, not with me.[/color]

No. The recommendation of 72 character lines is there to minimize the
number of wrapped lines and the damage done by broken programs. The
fault for breaking lines incorrectly is still with your program (not
with you, unless you desire that behavior).
[color=blue]
> Take your pick.[/color]

You program creates broken quotes. Conclusion: Your program is broken.
You can't blame anybody but the program for its actions.

Broken quotes is one of the worse bugs to have, since it attributes text
to the wrong author. I accept that your program is broken and you can't
help it, but don't think for a second that it is correct or desireable
behavior. And if you can fix it, please do.

/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'