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hcloh
05-06-2003, 10:09 PM
Hi everyone,
Would like to know what's the difference betwen these two statements:
<META HTTP-EQUIV="Expires" CONTENT="-1">
<META HTTP-EQUIV="Expires" CONTENT="0">
What's the difference using between "-1" and "0".
By the way, are there anyway to remove cache that store any script and images?
Thanks.
khalidali63
05-06-2003, 10:27 PM
both statements are suppose to let the browser / web server know that a fresh copy of the web page is required.
W3c stadnard does not define any values for the contents attribute,In my understanding value of the content is related to the webserver used.
Charles
05-07-2003, 04:58 AM
The HTTP-EQUIV META elements are supposed to allow web authors to tinker with the HTTP response header on some servers. Some browsers also pay attention to it, but we're really talking here about the HTTP specification. And both of those are illegal values. The header is supposed to employ a valid date of a particular format and relative values are not allowed. However, the specification does state that any illegal date is to be taken to have occured sometime in the past. Which is to say that those two statements are exactly he same.
hcloh
05-07-2003, 08:51 PM
I see. But seem like it's not working as i had put it into my code as below. It's for IE and Netscape.
_____________________________________________________
<html>
<head>
<title></title>
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="-1">
</head>
<body onLoad="if ('Navigator' == navigator.appName) document.forms[0].reset();" bgcolor="#CCCCCC" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
The context for main page are here .......
</body>
<HEAD>
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="-1">
</HEAD>
</html>
_____________________________________________________
Please help me ..... It's urgent. Thanks.
Rgds.
khalidali63
05-07-2003, 09:09 PM
It doesn't make sense,but did you try to use 0 or left it empty without any thing in it?
Charles
05-07-2003, 09:15 PM
It's not supposed to work. At least not necessarily. It's what's in the HTTP header that matters and some servers use those meta tags to adjust the HTTP header.
hcloh
05-07-2003, 09:24 PM
Had tried with "0".
So, you mean it should not?
I found that in http://www.htmlgoodies.com/beyond/nocache.html
Please advice. Thanks.
Charles
05-08-2003, 04:40 AM
HTML Goodies is a very, very bad site full of lots of incorrect and incomplete information. My advice is that you avoid it at all costs.
khalidali63
05-08-2003, 05:47 AM
Its a tough call,It could be the web server is not reading this http value ata all,in that case whatever you do is waste,
the typical value that http server should see is something like this
Expires: Tue, May 2004 17:20:00 GMT//expiration date is given
Expires: 0 //no cache intended
Pragma: no-cache
You might end up finding out that it was your webserver...So I kinda agree with charles that its one of those html things like "referer" where you are not completely independent.
DaveSW
05-08-2003, 12:49 PM
Originally posted by Charles
HTML Goodies is a very, very bad site full of lots of incorrect and incomplete information. My advice is that you avoid it at all costs.
[serious question]Are there any good sites out there in your opinion Charles? I regularly hear you shouting at sites, but never complimenting one![/serious question]
dave
nkaisare
05-08-2003, 01:42 PM
I am not answering on behalf of Charles. Its my personal experience speaking.
HTML goodies is nice for a beginer, as it starts simple and keeps things simple. But if you want to graduate to doing any serious web designing, HTML goodies leave a lot to be desired. I realized I had to unlearn a lot of things that I got from HTML goodies. I can't pinpoint at any right now, but I am sure there were a lot.
One site I would definitely recommend is
http://www.w3schools.com/
If you do HTMLing to make your family photos available to your grandma, HTMLgoodies is the site for you. If you want to attract potential recruiters or if you are into anything more than a only-for-my-family site, you need to learn.
I guess my dislike of HTMLgoodies stems from didn't-live-up-to-my-expectations syndrome. I have a page on my website that links to HTMLgoodies saying "This is the best site in the world". I actually thought that when I started HTMLing. And now that I understand things better than I did ca 3 years ago, I've begun to REALLY dislike HTMLgoodies.
Still, the site doesn't qualify for axis-of-evil.
Charles
05-08-2003, 01:59 PM
I have found HTML Goodies to be particularly bad for beginners. It teaches a lot of stuff that is simply wrong and beginners are not going to know that it's wrong. If they ever get around to the next step they will have to unlearn everything.
I'm afraid to say that I haven't seen too many sites that are any good. HTML Goodies is, however, the worst that I've seen. But this stuff isn't rocket science. All you need to do is go to the source. Just read, mark. learn and inwardly digest:
The HTML 4.01 Specification
http://www.w3.org/TR/html4/
The CSS2 Specification
http://www.w3.org/TR/REC-CSS2/
Web Content Accessibility Guidelines 1.0
http://www.w3.org/TR/WCAG10/
nkaisare
05-08-2003, 02:11 PM
Charles, its not easy to read specs. Thats why tutorials are required. Did you start off HTMLing reading the specs? You dont know what to read and what not to, when you are a beginer. How will he make sense out of (for example)
<!ELEMENT UL - - (LI)+ -- unordered list -->
<!ATTLIST UL
%attrs; -- %coreattrs, %i18n, %events --
>
<!ELEMENT OL - - (LI)+ -- ordered list -->
<!ATTLIST OL
%attrs; -- %coreattrs, %i18n, %events --
>
Robert Wellock
05-08-2003, 02:24 PM
All I am saying about is Joe Burns uses a lot of proprietary code and yes there are a lot of errors on the HTML Goodies website.
I learnt basic HTML within about half-an hour from reading a tag reference sheet and sitting with a web master for about ten minutes with a pencil and paper and he explained the basics.
The rest I taught myself for a few months then I began following the W3C Recommendations but we are talking early 1999 when Netscape 3.0 was still popular.
khalidali63
05-08-2003, 03:56 PM
I guess every one is correct in what they are saying,we just have to consider this,that HTML goodies tuts were probably written in late 9dees,Heck even html did not have much in it by then, some 50+ tags may be?
It doesnt sound fair to judge that on todays knowledge...if we do that then books written on physics 100yrs ago are jokes today..lol.
The action that is debateable on HTMLGoodies behalf is that they should have updated their pages.
:D
Charles
05-08-2003, 04:05 PM
Originally posted by nkaisare
How will he make sense out of (for example)
<!ELEMENT UL - - (LI)+ -- unordered list -->
<!ATTLIST UL
%attrs; -- %coreattrs, %i18n, %events --
>
<!ELEMENT OL - - (LI)+ -- ordered list -->
<!ATTLIST OL
%attrs; -- %coreattrs, %i18n, %events --
> Before getting to that he, or she, will have read the simple little section at http://www.w3.org/TR/html4/intro/sgmltut.html#h-3.3 and will know perfectly well what that stuff means. And if he, or she, has skipped reading that then he, or she, will find upon reading the spec that what follows immediately after each bit of that shorthand is the explanation.
nkaisare
05-08-2003, 04:16 PM
charles, are we both talking about the same person here? I am talking about someone who jumped with joy last Thursday because he could display "Hello World" on IE screen.
Khalid, exactly my point. HTML goodies was written in dark ages (the 90s). So it IS antiquated. Trash it :D:D:D!
I sadi this before, I say again... HTML goodies still does not figure in my axis-of-evil, no matter how much I flame (is that the right word?) it.
Charles
05-08-2003, 05:25 PM
If you must have some tutorials try these:
http://www.w3.org/MarkUp/Guide/
They're by Dave Raggett (http://www.w3.org/People/Raggett/) who wrote the HTML 3.2 Spec and HTML Tidy.
hcloh
05-08-2003, 09:15 PM
Guys,
Thanks a lot. Learn new things, and get few nice sites from you all. Thanks a lot.
khaki
05-08-2003, 11:44 PM
y'know... every time that someone refers me to w3 for a solution to something... i come away with even more questions than I started with :rolleyes:
w3... while a valuable and definitive source.... is more of a fact-checker or reference guide, than a resource for learning.
personally i find it like being told to read a Dictionary in order to learn how to speak (hey.... the words are all in there... aren't they? :)
Goodies might suck.... but I've learned a lot more from there as a beginner than I have yet to learn from w3 ever since (and as a matter of fact.... i've UN-learned less from Goodies than I have yet to learn from w3 :rolleyes: ).
in my opinion... the w3 is just "too much information" ... which is presented in a manner which is poorly dispensed.
I'd much rather have to un-learn later (and accomplish something now)... than to just stare blankly at something that tells me nothing that can help me until I become a master.
...like i said...
you don't learn to speak by reading a Dictionary...
even if it has all the words in it... :rolleyes:
preparing for the rebuttal.... :eek:
;) k
A1ien51
05-09-2003, 12:39 AM
Sad thing is that the no cache tags work when they want too. IE's fix from the microsoft site is to place the code in two sets of head tags.......LOL....talk about good practice! IE tends to over look them....
I recommend session ID's.
And I agree HTML goodies has information about building site for IE 3 compliance......
khaki
05-09-2003, 07:02 AM
well....
before i find myself in the indefensible position of trying to defend Goodies....
my opinions above were made more about the w3's lack of assistance to a beginner (or even some people who have moved beyond that stage) than about anything else.
i just don't find the w3 to be inuitive or helpful... although it is informative (just like a dictionary).
and just like a "writer" can't go the the dictionary whenever she/he is trying to find the proper word to use....
i find the w3 to be the same type of help:
if i know what i'm looking for... the w3 provides a technical explanation.
but if i'm not sure of what i'm looking for.... the w3 fails to provide intuitive assistance.
for the purpose that the w3 serves... it's great.
but as a reference to be offered for answers to real-world questions.... nah (in my opinion, anyway) :rolleyes:
;) k