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December 16, 2002-- Newsletter #211
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Goodies to Go (tm)
December 16, 2002--Newsletter #211
This newsletter is part of the internet.com network.
* Goodies Thoughts - I Never Met A Tag I Didn't Like!
* Q & A Goodies
* News Goodies
* Feedback Goodies
* And Remember This...
Just in case you missed it before, the new Beyond HTML Goodies book is now available!
|Goodies Thoughts -||I Never Met A Tag I Didn't Like! (Part 2)|
Last week, I started discussion of META tags, covering the nature of META tags and taking a look at the NAME variety. This week, I continue by taking a look at the HTTP-EQUIV variation. These are the META tags that have an HTTP-EQUIV attribute. If you missed last weeks newsletter, you can find it in the archive at http://www.htmlgoodies.com/letters .
HTTP-EQUIV META tags allow the web page developer to add the equivalent of HTTP header information into the web page itself. The browser can then access this information at the time the page is read. The server may also use it when the document is being sent. The format of this tag involves the HTTP-EQUIV attribute being set to the header type, while the CONTENT value provides the header information itself. As an example: <META HTTP-EQUIV="Expires" CONTENT="Tue, 31 Dec 2002 23:59:59 GMT"> sets the expiration date for the document to be the last second of this year, GMT (Greenwich, London.)
Some of the header equivalents available are as follows:
As in the example provided above, this tag provides an expiration date for a document. If a browser has a copy of a requested page in its cache, it will show that copy unless it has expired. If you, for example, update your page every day and want your visitors always to see the new version, you could set the expiration to midnight each night. The next day, their browser would request a fresh copy of your page.
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
This tells the browser not to store this page in cache in the first place. If you are doing this for security purposes, please remember that just because you have sent the instruction to the browser, does not mea it will follow it. There may be browsers that don't implement all the rules. Providing this tag may help, but is not a guarantee.
<META HTTP-EQUIV="Refresh" CONTENT="10;URL=http://www.displaysecond.com/page2.html">
Known as Client-Pull, this tag instructs the browser to fetch another page after a specified number of seconds. In this example, the browser will go to www.displaysecond.com/page2.html after displaying the current page for 10 seconds. A value of zero for the seconds will send the browser to the second page right away. Used creatively, this could provide a means for changing displayed content every few seconds. You might, for example, have a frame or iframe in which a series of pages invoke each other every five seconds, somewhat like a banner rotation.
<META HTTP-EQUIV="Window-target" CONTENT="_top">
<META http-equiv="PICS-Label" content='(PICS-1.1 "http://vancouver-webpages.com/VWP1.0/" l gen true comment "VWP1.0" by "email@example.com" on "2002.12.16T12:34-0800" for "http://www.authorsdomain.com/" r (P 2 S 0 SF -2 V 0 Tol -2 Com 0 Env -2 MC -3 Gam -1 Can 0 Edu -1 ))'>
Did you get that? The PICS-Label, Platform for Internet Content Selection, is a mechanism for rating pages for content filtering purposes. It involves a labeling system that can be identified by content filtering software to ensure that only suitable content finds its way, for example, into the classroom of a children's school. There is too much involved with this tag for discussion in this newsletter, but I can point you at http://www.w3.org/PICS for more information. There's also a free PICS-Label generator service at http://vancouver-webpages.com/VWP1.0/VWP1.0.gen.html .
Before closing, I should mention where on a page the META tags should appear. They belong in the head of the page, between the <HEAD> and </HEAD> tags, before the <BODY> tag.
There are a couple of useful META tag resources that I would also like to point out:
in WebDeveloper.com there is http://www.webdeveloper.com/html/html_metatag_res.html and in the Web Developer's Virtual Library,
Thanks for Reading!
- Vince Barnes
Questions are taken from submissions to our Community Mentors. You can ask a Mentor a question by going to http://www.htmlgoodies.com/mentors/.
Q. I have copyrighted pictures on my
website. I have disabled the right-click, so no
one can save the picture that way, but then
there's that LOVELY little Windows XP toolbar
that pops up that allows you to save from there.
Can you help me get this toolbar disabled?
A. By Windows XP toolbar, do you mean the browser toolbar? Yes, it's possible to load a window without it, though not remove it from the current window. Even then, the keyboard shortcuts will still work, and there are other ways around it too. Not only are you fighting a hopeless battle using technical means to make saving images tough, but as someone who uses the right click menu frequently I always resent having it taken. It's not good to annoy your visitors. Since technical means won't work, try two non-technical protections. One is to put a big copyright notice over the graphic. The other is to display just a small version on the web site, and ask anyone who wants the bigger version to contact you. Otherwise, the only way to prevent copying is to not put an image on the web at all.
Q. I'm having trouble with adding spaces on my website. I usually use Internet Explorer 6.0 for the internet. As was suggested, I also downloaded Netscape Navigator 7.0. When I view my site in Internet Explorer the space code " " doesn't show up as those letters, but as a space. But, in Netscape the space code " " doesn't show up until the very last time it is used.
A. The space codes in the problem area are not followed by a semicolon, whereas the spaces in the areas that are working have the required semicolon -- " ". Add the missing semicolons and you'll get spaces instead of code.
Q. I want to add a link on my pages that would allow my visitors to go back to the last page they were looking at, no matter which page it was (like the "Back" button, but a hyperlink). How do I code this?
Q. Do you use href to open a link in a new window?
A. Yes you do. You add the target="blank" for a new window. Code it like so:
<a href="http://www.somewhere.com" target="_blank">Somewhere</a>
Q. My server supports CGI, PERL, PHP & MySQL, but not ASP. What is the easiest way to add a shopping cart capability with credit card processing capability?
A. You can buy a shopping cart that will run on what your host supports. First check with your host to make sure that they allow uploading a shopping cart. Then take a look at this site: http://php.resourceindex.com/Complete_Scripts/Shopping_Carts/
It has a lot of pre-built carts that will run on a server that supports PHP. They seem fairly inexpensive. Before you buy one, make sure it has everything you are looking for and if possible, see if they offer a demo for you to try.
Q. I'd like to do is create a template (basically a header and footer) so that I can update the top and bottom of all my webpages by only altering one file for each.
A. You can use SSI to include a page at the top and a page at the bottom, if your server supports this. Take a look at this tutorial: http://www.htmlgoodies.com/beyond/asp.html
About half way down the page it explains SSI and include pages.
eBay Bidding Bye Bye to Billpoint
[December 16, 2002] Making good on its $1.5 billion PayPal acquisition, the auction giant will soon phase out its original P2P payment service.
AOL Wins Legal Round Against Spammers
[December 16, 2002] ISP wins a legal round against CN Productions, a long-running nemesis notorious for sending pornographic e-mails to AOL members.
IE Continues to Gain in Browser Wars
[December 16, 2002] Metrics show that Internet Explorer, already the dominant player by far, continues to gain share in the browser wars. But the numbers may not be all that accurate.
HotBot Redesign: Four Search Engines in One
[December 16, 2002] After a period of benign neglect, Terra Lycos intros a new HotBot, featuring an ad-free homepage and the ability to query FAST, Google, Inktomi and Teoma from a single interface.
Super Bowl Ads: Some Suit Up, Some Don't
[December 13, 2002] After the dot-com frenzy of 1999 and 2000, Internet and technology firms will have a lower profile during the commercial breaks of this year's game.
Virus-to-E-mail Ratio Grows Worse
[December 13, 2002] The e-mail security firm finds one virus in every 212 e-mails in 2002 (one virus every 3 seconds), a dramatic increase of the one virus per 380 emails last year.
Microsoft Unveils New Web Service
[December 12, 2002] The software giant raises the curtain on MapPoint .NET 3.0, with new location-based features and expanded street-level data.
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If you would like to comment on the newsletter or expand/improve on something you have seen in here, you can now send your input to:
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I'm still getting some feedback from a couple of
newsletters ago - the one concerning hacking. (If
you missed it, you can find it in the archive --
http://www.htmlgoodies.com/letters ) The ongoing
feedback is almost entirely from those who would
like me to understand that "hackers" are the good
guys, "crackers" are the bad guys. Folks, I do get
it! The problem is that to the general population
there is no such distinction. To most people
"crackers" either go with cheese or live in the
southern states! To the general population, the term
"hacker" has come to refer to those types who try to
break into computers and who may disrupt the normal
operation of those computers.
There was a Q&A item last week regarding the changing of a table cell's content from a hyperlink elsewhere on the page. Peter Breyfogle points out the the provided solution has difficulties in IE5, and offers this alternative solution (thanks, Peter):
If you give a cell a named anchor you can access it with cellname.innerHTML="New Stuff" thus:
<td><a href="#magiczone" onclick="magiczone.innerHTML='Look here now!'">Click to change something.</a></td>
<td><a name="magiczone">Pretty boring over here.</a></td>
And Remember This . . .
On this day in...
1789: Bill Of Rights Becomes Law
The first ten amendments to the Constitution of the United States of America became law on this day in 1789. Together, these ten amendments are known as the "Bill of Rights". Earlier that same year, in September, the first Congress of the United States passed twelve amendments to the constitution and sent them to the states for ratification. On this day, Virginia became the tenth of the fourteen states to ratify ten of the twelve amendments. This provided the two thirds majority required for the Bill of Rights to become law. The Bill of rights was based largely on the English Bill of Rights of 1689 and Virginia's Declaration of Rights written by George Mason in 1776. Of the two remaining amendments, one involved the population system of representation and has never been ratified. The other, which prohibits changes to Congressional Members pay until after an election, was finally ratified over two hundred years later, in 1992.
1951: "Dragnet" Previews
The television detective series, which had been a poplar radio show since 1949, ran from January 1952 until 1959. It is being revitalized and will be back on your screens very soon!
1966: Walt Disney died.
1998: Disney Exec Testifies Against Microsoft.
In the famous anti-trust suit against Microsoft, a Disney executive testified on this day that Microsoft agreed to provide a link to Disney in Windows only after Disney agreed to create content that could only be viewed in Microsoft Internet Explorer, causing Disney to scrap an earlier agreement with Netscape. Microsoft had been accused of unfairly leveraging its dominance in the operating system marketplace in order to gain advantage in the browser world.
Thanks for reading Goodies to Go!