Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #8395

Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions

Show all headers | View raw

"Richard Cornford" <Richard@litotes.demon.co.uk> writes:

> Eric Bednarz wrote:
>> Richard Cornford writes:
>>
>>> document.write(
>>> "<scr"+"ipt type='text/javascript' src='"+tmps[x]+"'></scr"+"ipt>"
>>> );
>>>
>>> The cargo-cult programming structure is the first (left-most)
>>> string concatenation operation. The final (right-most) string
>>> concatenation operation has some justification in some contexts.
>>> Its use in those contexts demonstrates a shallow understanding
>>> of the reasons for its use (as there are more efficient, shorter
>>> and more formally correct alternatives), and it was almost
>>> certainly that shallow understanding that inspired the real
>>> cargo-cult structure to the left. However, One context where
>>> the final (right-most) concatenation is purposeless is when it
>>> is found in an imported JS file, which is of course where
>>> Google's code search is finding it. So that too is pushing
>>> cargo-cult programming in the contexts where it is being found
>>> above.
>>
>> I’m getting the impression that you think that the purpose of
>> splitting and concatenating the generic identifier is somehow
>> related to escaping the ETAGO delimiter (‘</’),
>
> "Somehow related" seems applicable.

Well, I don’t understand what you mean by “some justification in some
contexts”. In the context of a CDATA content model it doesn’t make any
sense at all because CDATA ends with ETAGO foolowed by a name start
character. So that habit wouldn’t have made it valid HTML (4) either.

>> while it is much more likely to be related to Norton ‘Internet
>> Security’ inserting it’s dreaded SymError function after the
>> first instance of anything that looks like the start tag of a
>> script element (and ususally messing things up in the process).
>
> In a cause and effect relationship I would expect the cause to
> pre-date the effect. This concatenation 'trick' was common when I
> started working with javascript in 2001.

Well, I’m unlikely to ever catch up with that head start. :-)

References I’ve seen connecting this practice with NIS were from around
2004 to 2006, as far as I can remember.

> The odds are that it
> pre-dates Norton 'internet security'

But why? Were there *practical* problems that are not related to
validation?

> and my observations of Norton's
> inserted scripts have been that it has been varying over time.

That’s inherent with cat and mouse games. For a while it seems to have
been possible to prevent NIS from modifying the first script element in
the HTML source by preceding it with an HTML comment containing script
markup (this kind of thing is pretty hard to verify now, but it sounds
plausible; ad-hoc parsing is usually broken and gets fixed feature by
feature later).

> I also don't think that the mindset where people are scripting only
> for the default configurations of the most recent versions of 4 or 5
> known browsers will tend to leave then thinking about the possible
> actions of 'security' proxies (or being willing to take action to
> accommodate them if they did).

It doesn’t create much overhead, and might have been a best practice
that is so good that nobody checks what it is for ;-)

On the other hand, it’s really not easy to know which cargo cult bits
are redundant or not, and why. Somewhere around 2007 I removed HTML
comments out of script elements in the course of a redesign of a
website. I got kicked royally for that because the client had some
really crappy HTML to PDF conversion software that included the script
content after that.

> In any event, HTML mark-up modification is still not relevant to the
> contents of an imported javascript.

But it is supposed to have been *only* about external script, the
premise being that NIS was looking for the first occurance of something
that looks like a start tag of a script element, which isn’t a problem
in a HTML context.

Back to comp.lang.javascript | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-11-10 06:09 -0800
  Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-11-10 16:57 -0200
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-11-10 11:54 -0800
  Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Ant" <not@home.today> - 2011-11-10 19:47 +0000
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-11-10 13:07 -0800
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Matt McDonald <matt@fortybelow.ca> - 2011-11-10 14:12 -0700
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-11-11 07:26 -0800
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 -   How to Measure Element Dimensions Frobernik <nospam@nospam.com> - 2011-11-17 22:43 +0000
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 16:08 -0800
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How   to Measure Element Dimensions Frobernik <nospam@nospam.com> - 2011-12-06 21:18 +0000
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-06 14:13 -0800
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Gene Wirchenko <genew@ocis.net> - 2011-11-10 13:17 -0800
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Evertjan." <exjxw.hannivoort@interxnl.net> - 2011-11-10 22:43 +0000
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Richard Cornford" <Richard@litotes.demon.co.uk> - 2011-11-11 00:36 +0000
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Gene Wirchenko <genew@ocis.net> - 2011-11-10 19:14 -0800
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Richard Cornford" <Richard@litotes.demon.co.uk> - 2011-11-11 09:59 +0000
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Gene Wirchenko <genew@ocis.net> - 2011-11-11 11:04 -0800
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-11-11 14:39 +0100
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-11-12 10:38 +0100
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Richard Cornford" <Richard@litotes.demon.co.uk> - 2011-11-12 19:19 +0000
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2011-11-12 21:07 +0100
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-13 00:42 +0100
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Richard Cornford" <Richard@litotes.demon.co.uk> - 2011-11-13 14:33 +0000
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2011-11-17 23:14 +0100
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Richard Cornford" <Richard@litotes.demon.co.uk> - 2011-11-17 23:55 +0000
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-11-13 20:22 +0100
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions RobG <rgqld@iinet.net.au> - 2011-11-13 08:29 +1000
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-11-13 20:25 +0100
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions RobG <rgqld@iinet.net.au> - 2011-11-13 23:05 -0800
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Tim Down <timdown@gmail.com> - 2011-11-14 03:41 -0800
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions RobG <rgqld@iinet.net.au> - 2011-11-16 16:18 -0800
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 16:03 -0800
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-11-15 16:52 +0100
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 15:54 -0800
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2011-11-13 10:38 +0200
  Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Dr J R Stockton <reply1145@merlyn.demon.co.uk> - 2011-11-11 21:33 +0000
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 15:00 -0800
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 18:38 -0800
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-12-03 19:50 -0200
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-03 15:50 -0800
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-03 16:38 -0800
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-03 17:14 -0800
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2011-12-04 11:07 +0100
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-04 02:45 -0800
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-04 13:37 -0800
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-04 16:01 -0800
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-04 16:28 -0800
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-04 18:56 -0800
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions John G Harris <john@nospam.demon.co.uk> - 2011-12-05 14:39 +0000
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-05 11:00 -0800
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-03 19:17 -0800
  Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-11-13 00:06 -0200
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-13 04:31 +0100
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-11-13 13:44 -0200
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-13 18:35 +0100
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-11-13 22:00 -0200
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-14 12:40 +0100
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions "J.R." <groups_jr-1@yahoo.com.br> - 2011-11-14 11:52 -0200
                Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-14 15:40 +0100
          Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2011-11-17 11:16 +0100
            Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-17 21:06 +0100
              Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2011-11-17 22:13 +0100
        Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 15:19 -0800
    Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 15:10 -0800
      Re: David Mark's Javascript Tip Du Jour - Volume #1 - Tip #1234 - How to Measure Element Dimensions David Mark <dmark.cinsoft@gmail.com> - 2011-12-02 18:04 -0800

csiph-web