Textbox to dislplay Time (23:59) or empty string

[Joe Kovac]

Hi!

I want the user to edit a textbox which allows following values only:
- Time (Format: 23:59, HH:MM)
or
- NULL (empty string)
What can I do, so that this works kinda automatically, meaning on the
client side. It would be also nice, that not only errors would be
detected, but also that "wanted error" would be corrected if possible,
e.g. exchange "30" by "00:30".

Which control and properties do I need? As a reminder, I do not use a
bound field but a TextBox.

Thanks

Joe

 

[Hans Kesting]

Hi!

I want the user to edit a textbox which allows following values only:
- Time (Format: 23:59, HH:MM)
or
- NULL (empty string)
What can I do, so that this works kinda automatically, meaning on the
client side. It would be also nice, that not only errors would be
detected, but also that "wanted error" would be corrected if possible,
e.g. exchange "30" by "00:30".
Which control and properties do I need? As a reminder, I do not use a
bound field but a TextBox.

Thanks

Joe

You can add a RegularExpressionValidator.
Have the ControlToValidate property point to your textbox
and set the ValidationExpression to [0-2]?[0-9]:[0-5][0-9]
Set the ErrorMessage to the message you want to display if an error
is made.

This will validate that it looks like a correct time, or that nothing
is entered.

Note: the code that want this value (tries to store it?) should check
Page.Isvalid before using it.

Hans Kesting

 

[Mark Rae]

Hi!

I want the user to edit a textbox which allows following values only:
- Time (Format: 23:59, HH:MM)
or
- NULL (empty string)
What can I do, so that this works kinda automatically, meaning on the
client side. It would be also nice, that not only errors would be
detected, but also that "wanted error" would be corrected if possible,
e.g. exchange "30" by "00:30".

Which control and properties do I need? As a reminder, I do not use a
bound field but a TextBox.

I have a JavaScript function for this:

function isTime(pstrTime)
{
var strValidChars = "0123456789:";
var strChar;

if (pstrTime.length != 5) return false;

for (intChar = 0; intChar < pstrTime.length; intChar++)
{
strChar = pstrTime.charAt(intChar);
if (strValidChars.indexOf(strChar) == -1)
{
return false;
}
}

if (parseInt(pstrTime.substring(0, 2)) > 23) return false;
if (pstrTime.substring(2, 3) != ":") return false;
if (parseInt(pstrTime.substring(3)) > 59) return false;

return true;
}

 

[Mark Rae]

You can add a RegularExpressionValidator.
Have the ControlToValidate property point to your textbox
and set the ValidationExpression to [0-2]?[0-9]:[0-5][0-9]
Set the ErrorMessage to the message you want to display if an error
is made.

This will validate that it looks like a correct time, or that nothing
is entered.

Unless I'm very much mistaken, this would consider 29:59 as valid, wouldn't
it...?

 

[Joe Kovac]

I have a JavaScript function for this:

function isTime(pstrTime)
{
var strValidChars = "0123456789:";
var strChar;

if (pstrTime.length != 5) return false;

for (intChar = 0; intChar < pstrTime.length; intChar++)
{
strChar = pstrTime.charAt(intChar);
if (strValidChars.indexOf(strChar) == -1)
{
return false;
}
}

if (parseInt(pstrTime.substring(0, 2)) > 23) return false;
if (pstrTime.substring(2, 3) != ":") return false;
if (parseInt(pstrTime.substring(3)) > 59) return false;

return true;
}

I will give this function a try and moreover I will try to include the
auto complete that makes 00:30 out of 30.

Thanks to all of you so far.

 

[Mark Rae]

I will give this function a try and moreover I will try to include the
auto complete that makes 00:30 out of 30.

I would strongly advise against that sort of 'masked edit' functionality in
ASP.NET, especially if you're intending to wire it up to one of the
keystroke events of the TextBox...

I always have a single routine which validates the entire page rather than
individual control validation.

However, if you absolutely must do autocomplete, consider doing it in the
onblur() event...

 

[Joe Kovac]

I would strongly advise against that sort of 'masked edit' functionality
in ASP.NET, especially if you're intending to wire it up to one of the
keystroke events of the TextBox...

What exactly speaks against a (hopefully) comfortable auto completion?
(I currently think about performance, browser incompatibility, etc.)

I always have a single routine which validates the entire page rather
than individual control validation.

However, if you absolutely must do autocomplete, consider doing it in
the onblur() event...

How about onchange()?

 

[Mark Rae]

What exactly speaks against a (hopefully) comfortable auto completion? (I
currently think about performance, browser incompatibility, etc.)

Both of those... If you absolutely must roll your own autocomplete, you must
make absolutely sure that you switch the in-built autocomplete off for IE /
Opera 9:
http://www.google.co.uk/search?sour...BGB220GB220&q=<input+type="text"+autocomplete

How about onchange()?

onchange can be really irritating:
http://www.velocityreviews.com/foru...tching-value-of-ltinput-typequottextquot.html

 

[Hans Kesting]

You can add a RegularExpressionValidator.
Have the ControlToValidate property point to your textbox
and set the ValidationExpression to [0-2]?[0-9]:[0-5][0-9]
Set the ErrorMessage to the message you want to display if an error
is made.
This will validate that it looks like a correct time, or that nothing
is entered.

Unless I'm very much mistaken, this would consider 29:59 as valid,
wouldn't it...?

You are right.
I *knew* I had forgotten to check for those special situations :-(

(([01]?[0-9])|2[0-3]):[0-5][0-9]


Hans Kesting