So User gets fresh download of site when revisiting . . .

Discussion in 'HTML' started by rosco, May 29, 2004.

  1. rosco

    rosco Guest

    A site with frequent additions that would be missed by personal, local or
    regional cacheing of its URL . . .


    1) . . . from the archives in Google Groups -> alt.html --> "cache clear":
    <META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">
    In the Head of your html doc. Forces browser to not cache the page
    when it first loads

    <<< . . . does this work? . . . >>>


    2) . . . from source code of W3Schools home page
    http://www.w3schools.com/default.asp: <meta http-equiv="pragma"
    content="no-cache" />
    and <meta http-equiv="cache-control" content="no-cache" />

    <<< . . . the ' />' does not pass W3C markup validation in my hands. What
    gives? A XHTML transitional thing evidently. Will it work with the '>' tag
    in my CSS/html strict document? . . . >>>


    3) . . . from http://vancouver-webpages.com/META/metatags.detail.html
    Pragma
    Controls cacheing in HTTP/1.0. Value must be "no-cache". Issued
    by browsers during a Reload request, and in a document prevents Netscape
    Navigator cacheing a page locally.

    .. . . and . . .
    Expires
    Source: HTTP/1.1 (RFC2068)
    The date and time after which the document should be considered expired.
    Controls cacheing in HTTP/1.0. In Netscape Navigator, a request for a
    document whose expires time has passed will generate a new network request
    (possibly with If-Modified-Since). An illegal Expires date, e.g. "0", is
    interpreted as "now". Setting Expires to 0 may thus be used to force a
    modification check at each visit.

    Web robots may delete expired documents from a search engine, or schedule a
    revisit.

    .. . . and . . .
    Cache-Control
    Source: HTTP/1.1
    Specifies the action of cache agents. Possible values:

    a.. Public - may be cached in public shared caches
    b.. Private - may only be cached in private cache
    c.. no-cache - may not be cached
    d.. no-store - may be cached but not archived
    Note that browser action is undefined using these headers as META tags.

    .. . . and . . .
    Robots
    Source: Spidering
    Controls Web robots on a per-page basis. E.g.

    <META NAME="ROBOTS" CONTENT="NOINDEX,FOLLOW">
    Robots may traverse this page but not index it.
    Altavista supports:

    a.. NOINDEX prevents anything on the page from being indexed.
    b.. NOFOLLOW prevents the crawler from following the links on the page and
    indexing the linked pages.
    c.. NOIMAGEINDEX prevents the images on the page from being indexed but
    the text on the page can still be indexed.
    d.. NOIMAGECLICK prevents the use of links directly to the images, instead
    there will only be a link to the page.
    Google supports a NOARCHIVE extension to this scheme to request the Google
    search engine from caching pages; see the Google FAQ
    See also the /robots.txtexclusion method

    <<< . . . So. Pragma good. Expires bad (some search engines exclude
    site). Cache-control good. Robots/NoArchive .??? . . . that last sentence
    with NOARCHIVE doesn't make grammatical sense (like I should talk). Any
    thoughts? . . . >>>


    4). . . also, from http://vancouver-webpages.com/META/metatags.detail.html
    HTTP-EQUIV tags
    META tags with an HTTP-EQUIV attribute are equivalent to HTTP headers.
    Typically, they control the action of browsers, and may be used to refine
    the information provided by the actual headers. Tags using this form should
    have an equivalent effect when specified as an HTTP header, and in some
    servers may be translated to actual HTTP headers automatically or by a
    pre-processing tool.
    Note: While HTTP-EQUIV META tag appears to work properly with Netscape
    Navigator, other browsers may ignore them, and they are ignored by Web
    proxies, which are becoming more widespread. Use of the equivalent HTTP
    header, as supported by e.g. Apache server, is more reliable and is
    recommended wherever possible.

    <<< . . . If http-equiv meta tags are ignored by some browsers, or will be
    one day, then what good is all this? Should I investigate if there is
    java-script that insures my site is freshly loaded when revisited by a user?
    .. . .>>>

    Thanks in Advance,

    Rosco
    rosco, May 29, 2004
    #1
    1. Advertising

  2. rosco

    Neal Guest

    On Fri, 28 May 2004 22:37:54 -0600, rosco <> wrote:

    >
    > <<< . . . the ' />' does not pass W3C markup validation in my hands.
    > What
    > gives? A XHTML transitional thing evidently. Will it work with the '>'
    > tag
    > in my CSS/html strict document? . . . >>>


    It's an XHTML empty tag. To use in HTML, remove the space and the /.

    > 4). . . also, from
    > http://vancouver-webpages.com/META/metatags.detail.html
    > HTTP-EQUIV tags
    > META tags with an HTTP-EQUIV attribute are equivalent to HTTP headers.
    > Typically, they control the action of browsers, and may be used to refine
    > the information provided by the actual headers. Tags using this form
    > should
    > have an equivalent effect when specified as an HTTP header, and in some
    > servers may be translated to actual HTTP headers automatically or by a
    > pre-processing tool.
    > Note: While HTTP-EQUIV META tag appears to work properly with Netscape
    > Navigator, other browsers may ignore them, and they are ignored by Web
    > proxies, which are becoming more widespread. Use of the equivalent HTTP
    > header, as supported by e.g. Apache server, is more reliable and is
    > recommended wherever possible.
    >
    > <<< . . . If http-equiv meta tags are ignored by some browsers, or will
    > be
    > one day, then what good is all this? Should I investigate if there is
    > java-script that insures my site is freshly loaded when revisited by a
    > user?
    > . . .>>>


    If you are on an Apache server and can use .htaccess, or if you run your
    own server, you'll rarely need or want meta tags. Meta tags are currently
    useful, however, for folks who cannot actually manipulate the HTTP
    headers. What you do depends on what your situation is. One way is the
    established protocal and is more dependable, the other is rather widely
    supported but not the proper way to do it, so who knows what tomorrow
    brings.
    Neal, May 29, 2004
    #2
    1. Advertising

  3. rosco

    rosco Guest

    I just found this JS code link on the nsg comp.lanq.javascript:
    http://jibbering.com/faq/#FAQ4_1

    "".17 How do I force a reload from the server/prevent caching?
    To reload a page, location.reload() works, however this does depend on the
    cache headers that your server sends, to change this you need to change your
    server - a quick fix to this on the client side is to change the URI of the
    page so it contains a unique element such as the current date.
    location.replace(location.href+'?d='+new Date().valueOf()) of if the
    location.href already contains a Query String
    location.replace(location.href+'&d='+new Date().valueOf()) ""

    http://www.mnot.net/cache_docs/
    http://devedge.netscape.com/library/manuals/2000/javascript/1.3/reference/date.html


    << . . . I don't know any javascript. If the "forced reload" feature is
    important to me, should I learn JS, just for this, and not rely on meta
    http-equiv tags -- or do both? . . . >
    Rosco
    rosco, May 29, 2004
    #3
  4. rosco

    Neal Guest

    On Fri, 28 May 2004 23:17:57 -0600, rosco <> wrote:

    > I just found this JS code link on the nsg comp.lanq.javascript:
    > http://jibbering.com/faq/#FAQ4_1
    >
    > "".17 How do I force a reload from the server/prevent caching?
    > To reload a page, location.reload() works...
    > << . . . I don't know any javascript. If the "forced reload" feature is
    > important to me, should I learn JS, just for this, and not rely on meta
    > http-equiv tags -- or do both? . . . >



    Javascript is NOT necessarily part of the browser's package. You would do
    well to assume it will not exist, and plan your site accordingly.
    Certainly you may include "extras" in case it is enabled, but do not rely
    on it being enabled for your ends to be met.
    Neal, May 29, 2004
    #4
  5. rosco

    brucie Guest

    in post: <news:qwUtc.162$p%>
    rosco <> said:

    > <META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">
    > <<< . . . does this work? . . . >>>


    no

    > <meta http-equiv="pragma" content="no-cache" />
    > <meta http-equiv="cache-control" content="no-cache" />


    no

    > <<< . . . the ' />' does not pass W3C markup validation in my hands.


    xhtml

    > Controls cacheing in HTTP/1.0. Value must be "no-cache". Issued
    > by browsers during a Reload request, and in a document prevents Netscape
    > Navigator cacheing a page locally.


    no

    > Expires


    no

    > Cache-Control


    no

    > So. Pragma good.


    no

    it doesn't matter what you do ultimately if goodies are cached or not is
    up to the visitors settings.

    <p>please hit refresh as this page has frequent changes</p>

    very simple and you don't annoy the crap out of people who are forced to
    wait for the pages/images/etc to download *each and every time they view
    them*. its very bloody annoying, it wastes peoples time, money and
    bandwidth.

    if for some reason you still insist on trying to be a control freak at
    least cache for a few hours so people can view your goodies without the
    wait, then if they come back (doubtful) they have to download them
    again.

    this requires the host to have the mod_expires module enabled (most do).

    stick something like this in a .htaccess file:

    ExpiresActive On
    ExpiresByType text/html "access plus 1 day"
    ExpiresByType image/png "access plus 1 hour 3 minutes"
    ExpiresByType image/jpg "modification plus 2 hours"

    Module mod_expires
    http://httpd.apache.org/docs/mod/mod_expires.html

    but its still ultimately up to the visitors settings if your suggestions
    are ignored or not.

    --
    b r u c i e
    brucie, May 29, 2004
    #5
  6. > headers. What you do depends on what your situation is. One way is the
    > established protocal and is more dependable, the other is rather widely
    > supported but not the proper way to do it,


    I assume using .htaccess for this is considered more reliable?
    e n | c k m a, May 30, 2004
    #6
  7. rosco

    rosco Guest

    Thanks,
    R.
    rosco, May 31, 2004
    #7
  8. rosco

    KLB Guest

    It is my understanding that the majority of browsers in use today do are
    enabled to handle JavaScript -- better than 90%, in fact. This would seem
    to make the aforementioned JS code a viable option to obtain the feature
    desired.
    KLB, May 31, 2004
    #8
  9. rosco

    Mark Parnell Guest

    On Sun, 30 May 2004 22:48:15 -0600, "KLB" <> declared
    in alt.html:

    > It is my understanding that the majority of browsers in use today do are
    > enabled to handle JavaScript


    Yes, most of the browsers around _can_ handle Javascript, but many
    people surf with Javascript disabled.

    > better than 90%, in fact.


    There are no reliable figures, but most estimates say around 15% of
    people have Javascript disabled/unavailable. Even assuming that it is
    only 10% (i.e. 90% have Javascript), that's a fairly significant number.
    But it's your choice - if you want to make your site impossible to use
    for 1 in 10 potential customers, go ahead.

    BTW: Please quote the relevant parts of the post you are replying to.
    Thanks.

    --
    Mark Parnell
    http://www.clarkecomputers.com.au
    Mark Parnell, May 31, 2004
    #9
  10. rosco

    rosco Guest

    "brucie" <> whined:

    >
    > very simple and you don't annoy the crap out of people who are forced to
    > wait for the pages/images/etc to download *each and every time they view
    > them*. its very bloody annoying, it wastes peoples time, money and
    > bandwidth.
    >
    > if for some reason you still insist on trying to be a control freak at
    > least cache for a few hours so people can view your goodies without the
    > wait, then if they come back (doubtful) they have to download them
    > again.


    .. . . in my case, I would use such code only on my home page, which has no
    images, no gifs, no JS currently, and just minimal text. The images, which
    are the only thing anyone might want to revisit, are all on secondary pages
    and those I would no try to inhibit cacheing. The home page will serve,
    with its minimal text, to indicate new links to new images, and would
    therefore be worthless as a cached URL. And with just minimal text, there
    would be very little difference in the time it takes to freshly download a
    current version compared to a cached version -- unless, of course, a
    paranoid clueless ghit is operating from a 56k connection and bungs up there
    browser with bloated anti-virals and layers of porn filters.

    And just what kind of pansy wanker calls himself 'brucie' anyway.
    rosco, May 31, 2004
    #10
  11. rosco

    Mark Parnell Guest

    On Sun, 30 May 2004 23:26:44 -0600, "rosco" <> declared
    in alt.html:

    > unless, of course, a
    > paranoid clueless ghit is operating from a 56k connection


    What about brucie on his 14k (if he's lucky) connection?

    > And just what kind of pansy wanker calls himself 'brucie' anyway.


    Our kind.

    --
    Mark Parnell
    http://www.clarkecomputers.com.au
    Mark Parnell, May 31, 2004
    #11
  12. rosco

    brucie Guest

    in post: <news:rmzuc.1345$>
    rosco <> said:

    >> if for some reason you still insist on trying to be a control freak at
    >> least cache for a few hours so people can view your goodies without the
    >> wait, then if they come back (doubtful) they have to download them
    >> again.


    > . . . in my case, I would use such code only on my home page, which has no
    > images, no gifs, no JS currently, and just minimal text.


    you're still making them download the page again when you don't have to.

    > And with just minimal text, there would be very little difference in
    > the time it takes to freshly download a current version compared to a
    > cached version


    there is a noticeable difference even if the browser is just checking
    for a 304. i don't understand your insistence on not caching when its
    not needed or the best solution.

    > And just what kind of pansy wanker calls himself 'brucie' anyway.


    it must be skool holidays.

    --
    b r u c i e
    brucie, May 31, 2004
    #12
  13. rosco

    Mabden Guest

    "rosco" <> wrote in message
    news:rmzuc.1345$...
    > And just what kind of pansy wanker calls himself 'brucie' anyway.


    What should a pansy wanker call himself? Perhaps, Rosco?

    --
    Mabden
    Mabden, May 31, 2004
    #13
  14. Mark Parnell wrote:

    > if you want to make your site impossible to use
    > for 1 in 10 potential customers, go ahead.


    My favourite way to make my site impossible to use for 1 in 10 potential
    customers is to power down the server on New Year's Day and leave it
    switched off until early February.

    That's a much easier way to alienate customers than having to go fiddling
    with the DOM.

    --
    Toby A Inkster BSc (Hons) ARCS
    Contact Me - http://www.goddamn.co.uk/tobyink/?page=132
    Toby A Inkster, May 31, 2004
    #14
  15. rosco

    Whitecrest Guest

    In article <t733xz3gbe21$>,
    says...
    > There are no reliable figures, but most estimates say around 15% of
    > people have Javascript disabled/unavailable. Even assuming that it is
    > only 10% (i.e. 90% have Javascript), that's a fairly significant number.
    > But it's your choice - if you want to make your site impossible to use
    > for 1 in 10 potential customers, go ahead.


    In addition to the percentage that has Javascript turned off, you also
    have to look at the dynamics of the people that have it turned off.
    Depending on the content of your site, it can make the fact that these
    people have it off completely insignificant, OR it can make it much more
    significant than 15%
    --
    Whitecrest Entertainment
    www.whitecrestent.com
    Whitecrest, May 31, 2004
    #15
  16. rosco

    Whitecrest Guest

    In article <rmzuc.1345$>,
    says...
    > And just what kind of pansy wanker calls himself 'brucie' anyway.


    Pansy wanker?
    --
    Whitecrest Entertainment
    www.whitecrestent.com
    Whitecrest, May 31, 2004
    #16
  17. rosco

    Mabden Guest

    "Whitecrest" <> wrote in message
    news:...
    > In article <rmzuc.1345$>,
    > says...
    > > And just what kind of pansy wanker calls himself 'brucie' anyway.

    >
    > Pansy wanker?



    It's a type of British flower. It self-fertilizes.

    --
    Mabden
    Mabden, Jun 1, 2004
    #17
  18. rosco

    rosco Guest

    Obviously Mabden would do.
    rosco, Jun 2, 2004
    #18
  19. rosco

    rosco Guest

    How nice to have a boyfriend.
    rosco, Jun 2, 2004
    #19
  20. rosco

    Neal Guest

    On Tue, 1 Jun 2004 19:31:32 -0600, rosco <> wrote:

    > Obviously Mabden would do.


    Hahahahaha! That's so funny... You're a quick wit.
    Neal, Jun 2, 2004
    #20
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. TiNo
    Replies:
    5
    Views:
    348
  2. gnewsgroup

    Revisiting AutoEventWireup

    gnewsgroup, Jan 16, 2008, in forum: ASP .Net
    Replies:
    6
    Views:
    421
    David Anton
    Jan 16, 2008
  3. Winston
    Replies:
    0
    Views:
    291
    Winston
    Mar 25, 2010
  4. Winston
    Replies:
    8
    Views:
    270
    Cameron Simpson
    Mar 26, 2010
  5. Dave Anderson

    Revisiting an old friend: Set oRS = Nothing

    Dave Anderson, May 5, 2004, in forum: ASP General
    Replies:
    27
    Views:
    255
    Bob Barrows [MVP]
    May 28, 2004
Loading...

Share This Page