Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > HTML > Prevent user from entering punctuation

Reply
Thread Tools

Prevent user from entering punctuation

 
 
PW
Guest
Posts: n/a
 
      06-18-2006

Hi,

Is there anyway to format a text input so the user cant enter punctuation
marks?

TIA,
PW



 
Reply With Quote
 
 
 
 
tbar
Guest
Posts: n/a
 
      06-18-2006
www.pixar.com
 
Reply With Quote
 
 
 
 
Jonathan N. Little
Guest
Posts: n/a
 
      06-18-2006
PW wrote:
> Hi,
>
> Is there anyway to format a text input so the user cant enter punctuation
> marks?


Before it is posted, your can use JavaScript to check the input, but
that is no guarantee because the user may have JavaScript disabled. You
should *always* check user input upon the receiving end at the
server-side script. There is where you can make the final and absolute
check of the input. You can either quietly filter out the unwanted
characters or return to then previous form with an error message.

--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com
 
Reply With Quote
 
tbar
Guest
Posts: n/a
 
      06-18-2006
Isn't Disney bound to a 3d thing for xmas
 
Reply With Quote
 
Beauregard T. Shagnasty
Guest
Posts: n/a
 
      06-18-2006
tbar wrote:

> Isn't Disney bound to a 3d thing for xmas


Ok. You've discovered Usenet. Now go away until you realize just what it
is.

--
-bts
-thinking about the killfile
 
Reply With Quote
 
PW
Guest
Posts: n/a
 
      06-18-2006

Yeah, thats what I was afraid of.

Thanks for the info,
PW




"Jonathan N. Little" <(E-Mail Removed)> wrote in message
news:ab3db$4494c287$40cba7a5$(E-Mail Removed)...
> PW wrote:
>> Hi,
>>
>> Is there anyway to format a text input so the user cant enter punctuation
>> marks?

>
> Before it is posted, your can use JavaScript to check the input, but that
> is no guarantee because the user may have JavaScript disabled. You should
> *always* check user input upon the receiving end at the server-side
> script. There is where you can make the final and absolute check of the
> input. You can either quietly filter out the unwanted characters or return
> to then previous form with an error message.
>
> --
> Take care,
>
> Jonathan
> -------------------
> LITTLE WORKS STUDIO
> http://www.LittleWorksStudio.com



 
Reply With Quote
 
Jonathan N. Little
Guest
Posts: n/a
 
      06-18-2006
Beauregard T. Shagnasty wrote:
> tbar wrote:
>
>> Isn't Disney bound to a 3d thing for xmas

>
> Ok. You've discovered Usenet. Now go away until you realize just what it
> is.
>


Well, he thinks he's being clever,

--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com
 
Reply With Quote
 
Blinky the Shark
Guest
Posts: n/a
 
      06-18-2006
Beauregard T. Shagnasty wrote:
> tbar wrote:
>
>> Isn't Disney bound to a 3d thing for xmas

>
> Ok. You've discovered Usenet. Now go away until you realize just what it
> is.


>--
> -bts
> -thinking about the killfile


BtS encouraging it, as usual.

--
Blinky RLU 297263
Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html
Coming Soon: Filtering rules specific to various real news clients
 
Reply With Quote
 
Jukka K. Korpela
Guest
Posts: n/a
 
      06-18-2006
Jonathan N. Little <(E-Mail Removed)> scripsit:

> Before it is posted, your can use JavaScript to check the input, but
> that is no guarantee because the user may have JavaScript disabled.
> You should *always* check user input upon the receiving end at the
> server-side script.


In this particular case, the check should probably be made _only_ in the
server.

As a rule, it is a good idea to consider setting up client-side checking as
well, after you have designed and implemented the server-side check.
Immediate checking is good for usability and accessibility: the user gets an
error message at an early phase where he remembers what he just did and has
the context and position in front of his years, literally or figuratively.

However, double checking tends to be expensive in terms of implementation
and maintenance work. You normally use two quite different programming
languages, JavaScript for client-side checking and something else for
server-side checking. This means duplicate coding; only the overall logic is
the same. Moreover, any changes need to be implemented twice, and this means
that some day you (or you successor as the maintainer) will forget this.
Testing needs to be duplicated, too - with scripting enabled and scripting
disabled. Testing the client-side checking is problematic, since there are
differences between browsers in JavaScript implementations.

So although it is a good idea to _consider_ client-side checking, due
consideration does not that often lead to _implementation_ of client-side
checking. In this particular case, the problem is particular hard. It is
much harder than people naively think, since they typically imply the ASCII
character repertoire.

A well-designed form handler is prepared to anything, including any Unicode
character in input data, since there is no reliable way to prevent users
from inputing any character, intentionally or accidentally. And when your
data is Unicode data, the question "what is a punctuation character?" is far
from trivial. Apparently e.g. Arabic triple dot punctuation mark and Greek
ano teleia and Tibetan mark tsheg shad are punctuation marks, right? Would
you even include all characters with a General Category value starting with
"P"? And no other? That would be a technically simple definition, and you
could write the check using a suitable function in a suitable subroutine
library - if you use an advanced programming language. But would that really
match what you want it to match?

My point here is that you probably want to define a _positive_ rule (which
characters are allowed) rather than a negative rule (which characters are
not allowed). The rule should correspond to the repertoire of characters
that your form handler and other software and data formats involved are
prepared to handle. There's no point in accepting a character on input if it
will be lost or distorted in the actual processing, e.g. when saving to a
database.

--
Jukka K. Korpela ("Yucca")
http://www.cs.tut.fi/~jkorpela/

 
Reply With Quote
 
code_wrong
Guest
Posts: n/a
 
      06-18-2006

"PW" <(E-Mail Removed)> wrote in message
news:SX1lg.11231$(E-Mail Removed)...
>
> Hi,
>
> Is there anyway to format a text input so the user cant enter punctuation
> marks?
>


what's wrong with punctuation?


 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
prevent from entering some bad websites after searching Mike Computer Support 11 04-10-2009 11:54 PM
restrict the user entering nonalphanumeric keys? =?Utf-8?B?Qw==?= ASP .Net 1 06-13-2007 10:31 PM
Prevent entry of punctuation PW ASP General 1 06-18-2006 07:48 AM
IOS user authentication when entering enable mode MayaShani@gmail.com Cisco 3 03-13-2006 07:07 AM
Prevent entering data into DB twice =?Utf-8?B?bWdAdGhld29ybGQuY29t?= ASP .Net 3 06-09-2004 07:48 PM



Advertisments