- META tags
I have touched on META tags already on the "Get Noticed" page.
META tags have a wide variety of applications, but they primarily include
information about a document such as the creation date, author page contents,
etc. The information in a META tag is primarily useful to servers, web
browsers and search engines but it is invisible to the user. META tags
are placed inside the <HEAD> tag.
- The HTTP-EQUIV Attribute
The information provided by the HTTP-EQUIV attribute is added to
the HTTP response header. This response header contains all sorts
of
useful MIME type information that the server sends to the browser
to tell the browser how to handle the information in the file
it is about to receive. If you are like me, you really hate those
stupid
MIMEs too. The striped shirts, the painted faces, the ambiguous
sexuality, the trapped in freakin' the box gag. Gosh, if it weren't
for the
law and the threat of living in an 8X12 for the next 40 years
with some no-neck named Buba, I would take a rusty, red-hot fire
ax to
the lot of them and hang their pasty, pimple flecked hides to
dry on my back fence.
- META tags for client pulls
Wow, I broke a tooth I had my jaw clamped so
hard! Criminy, where was I? OH! There are lots of predefined HTTP-EQUIV
types available
but we are only interested in client pulls here so we will focus
on the "refresh" attribute
value. For a complete listing see the Dictionary
of HTML META Tags.
As I mentioned in the introduction, a client-pull refers to the
ability of the browser (the client) to automatically request (pull)
a new
document from the server. The effect for the user is that the page
displays, and after a predefined period of time, automatically
refreshes with new information, is replaced by an entirely new page,
or even
a file starts downloading! Long ago client-pulls were used for
doing crude animation but now much better techniques are available
and
anyway we are here to learn how to redirect users to a different
page when they hit a retired URL.
The syntax used is:
<
META HTTP-EQUIV="name" CONTENT="content">
The client-pull uses the refresh attribute value. It tells the
browser to wait the number of seconds you specify in value of the
CONTENT attribute.
If you want your page to refresh automatically every 20 seconds (you do have
some updated information the server is going to put there right...
RIGHT??) then you would use a statement like this:
<
META HTTP-EQUIV="refresh" CONTENT="20">
Now if you wanted to send the user to a different URL in 10 seconds
the statement would be:
<
META HTTP-EQUIV="refresh" CONTENT="10; URL=http://www.mybuttonascanner.com/">
Careful now me boyo, notice how the quotes go all the way around
the value of the CONTENT attribute. Normally URLs have their own
set of
quotes, but the delay time is part of that same value.
Have the page start automatically downloading a file:
<
META HTTP-EQUIV="refresh" CONTENT="0; URL=http://www.mybuttonascanner.com/butt.doc">
Want a web site that shows off your works of art in a looping slide
show? Do something like this:
Document butt1.html contains:
<
META HTTP-EQUIV="refresh" CONTENT="30; URL=http://www.mybuttonascanner.com/butt2.html">
Document butt2.html contains:
<
META HTTP-EQUIV="refresh" CONTENT="30; URL=http://www.mybuttonascanner.com/butt3.html">
Document butt3.html contains:
<
META HTTP-EQUIV="refresh" CONTENT="30; URL=http://www.mybuttonascanner.com/butt1.html">
Put an easy-to-click link on each page that will take your user out
of the loop or he will bail on you the second he starts burping up
bits of the road kill he swallowed whole for lunch. Also keep in
mind when you set the refresh time, the speed the page (graphics
or no graphics)
will load depends on file size, server speed and general web traffic.
a value of zero will trigger the next page as soon as the current
page has downloaded.
- Sorry for all the confusion
I have a confession to make. In the "HTTP-EQUIV Attribute" section
above I just sort of launched into mimes like a stomach kicked pit
bull in a blinded rabid fury for no reason at all. It turns out that
MIME means "file type" and it stands for "Multipurpose
Internet Mail Extension", not to be confused with "Mentally
Incompetent Mole Excrement" as I first surmised. You see, servers
add a header to each document that tells the browser the type of
file it is sending. The browser determines how to handle the file
based
on that information. It tells the browser whether it needs to display
the contents in a window, or to launch a plug-in or helper application.
This system for communicating media types closely resembles MIME
which was developed for sending attachments in e-mail and hence my
confusion.
Boy is my face red. I stand behind each and every word I ranted about
mimes though!!
- An Example!
If you like you can link to the page I modified to be my Chili
Page URL redirect page and see this thing in action. As I stated earlier,
make sure it has the exact URL of the old page, and this includes
all the invisible named anchors that someone might have bookmarked
or linked
to! I mean, you never know, anyway it couldn't hoit. One last thing,
make sure there is a manual link to the new page that the user
can click if for some reason the refresh fails.
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