regular expression 1

arst06d · Mar 21, 2006

Hi
Can anyone please tell me whether it is possible to use a regular expression to test both for the format of a value - eg no more than 2 decimal places

Code:

/\d*(\.\d{1,2})?/

as well as validating that it falls within a given range?

Thanks

kaht · Mar 21, 2006

The regular expression you provided checks for any number of numeric characters followed by either no decimal, or a decimal with between 1 and 2 numbers after the decimal. If you're wanting to know if it's possible to check for a numeric range within the regexp - then the answer is yes, but it gets considerably more difficult. I recently did one to see if I could and I ended up needing a ton of or (|) conditions to get it to work. In my opinion, it's just a lot easier to compare the values after you've determined that the value is the correct format.

In case you're curious, here's the regexp I wrote. It checks for a valid number between .00~1 and 8:

Code:

if (!/^((0*[1-8]{1}(\.0+)?)|(0*[1-7]{1}(\.\d+))|(0*\.0*[1-9]+\d*)){1}$/.test(hourAmount)) {

-kaht

[small] <.[/small]
[banghead]

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arst06d · Mar 21, 2006

blimey!
I think I'll take your advice and check the range seperately.

Cheers

arst06d · Mar 21, 2006

errr - looks like I can't even get past the first hurdle - appreciate some advice here.

Code:

    var valid = new Object();

    // REGEX Elements

	//number with max 2 decimals
	valid.NumTo2dp = /\d*(\.\d{1,2})?/;   
    
    
    function validateForm(theForm) 
    {
		var elArr = theForm.elements; 		
		for(var i = 0; i < elArr.length; i++)
		{	
			with(elArr[i])						{              
				var v = elArr[i].validator;		
				if(!v) continue;				
   
				var thePat = valid[v];			
				var gotIt = thePat.exec(value); 
				
			
				if(!gotIt)
				{
					alert(name + ": failure to match " + v + " to " + value);
					return false;
				}
			}
		}				
		return true;
	}

I have an input box with validator="NumTo2dp" but it seems to accept any value entered - ie the variable gotIt is never null.

kaht · Mar 21, 2006

It looks like you're trying to create an object to do the validation when there's really no need. Just set up your validation function like so:

Code:

function validateForm(theForm) {
   var elArr = theForm.elements;         
   for(var i = 0; i < elArr.length; i++) {    
      if (/\d*(\.\d{1,2})?/.test(elArr[i].value)) {
         if (parseFloat(elArr[i].value) > maxLimit || parseFloat(elArr[i].value) < minLimit) {
            alert(elArr[i] + " must be between x and y, please enter a new value");
            elArr[i].focus();
            return false;
         }
      }
      else {
         alert(elArr[i] + " is not formatted correctly, please enter a new value");
         elArr[i].focus();
         return false;
      }
   }
   return true;
}

-kaht

[small] <.[/small]
[banghead]

[small](He's back)[/small]

arst06d · Mar 21, 2006

Hi Kaht

I was trying to create a generic form validator - this particular regexp is just the beginning ....

even doing it the way you suggest (ignoring the min & max value at the mo) I still cannot generate the error message no matter whether I input text or leave the input blank.

kaht · Mar 21, 2006

can you post a view-source of your page so that I can create a local copy and try to debug from there?

-kaht

[small] <.[/small]
[banghead]

[small](He's back)[/small]

arst06d · Mar 21, 2006

here's the page

Code:

<HTML>
<HEAD>
<META NAME="GENERATOR" Content="Microsoft Visual Studio 6.0">
<TITLE></TITLE>
<SCRIPT LANGUAGE=javascript src="validator.js">
<!--

//-->
</SCRIPT>


</HEAD>
<BODY>

<form onsubmit="return validateForm(this)">

<INPUT type="text" id="text1" name="text1" validator="NumTo2dp"><br>
<INPUT type="submit" value="Button" id=button1 name=button1>

</form>


</BODY>
</HTML>

and the js

Code:

    // Validator Object
            
    var valid = new Object();

    // REGEX Elements

		//number with max 2 decimals
		valid.NumTo2dp = /\d*(\.\d{1,2})?/;   
    
/*    
    function validateForm(theForm) 
    {
		var elArr = theForm.elements; // get all elements of the form into array
		
		for(var i = 0; i < elArr.length; i++)
		{	
			with(elArr[i])						// for each element of the form...
			{              
				var v = elArr[i].validator;		// get validator, if any
				if(!v) continue;				// no validator property, skip
   
				var thePat = valid[v];			// select the validating regular expr
				var gotIt = thePat.exec(value); // run it on value of elArr[i]
				alert("gotIt: " + gotIt);
			
				if(!gotIt)
				{
					alert(name + ": failure to match " + v + " to " + value);
					return false;
				}
			}
		}				
		return true;
	}
*/
function validateForm(theForm) {
   var elArr = theForm.elements;         
   for(var i = 0; i < elArr.length; i++) {    
      if (/\d*(\.\d{1,2})?/.test(elArr[i].value)) {
         //if (parseFloat(elArr[i].value) > maxLimit || parseFloat(elArr[i].value) < minLimit) {
         //   alert(elArr[i] + " must be between x and y, please enter a new value");
         //   elArr[i].focus();
         //   return false;
         //}
      }
      else {
         alert(elArr[i] + " is not formatted correctly, please enter a new value");
         elArr[i].focus();
         return false;
      }
   }
   return true;
}

kaht · Mar 21, 2006

Here is the modified function:

Code:

function validateForm(theForm) {
   var elArr = theForm.elements;
   for(var i = 0; i < elArr.length; i++) {
      if [!](elArr[i].type == "text")[/!] {
         if (/^((\d+(\.\d{1,2})?)|(\d*(\.\d{1,2}){1}))$/.test(elArr[i].value)) {
            //if (parseFloat(elArr[i].value) > maxLimit || parseFloat(elArr[i].value) < minLimit) {
            //   alert(elArr[i] + " must be between x and y, please enter a new value");
            //   elArr[i].focus();
            //   return false;
            //}
         }
         else {
            alert(elArr[i].value + " is not formatted correctly, please enter a new value");
            elArr[i].focus();
            return false;
         }
      }
   }
   return true;
}

I put the highlighted check in because you don't want to perform the validation check on the button.

I had to split the regexp up with an or clause. This is the reason why:

Your old regexp:
/\d*(\.\d{1,2})?/

When split up is a 2 part process

[ol][li]\d* means 0 or more numbers[/li]
[li](\.\d{1,2})? means 0 or 1 instances of a decimal followed by 1 or 2 numbers.[/li][/ol]

When you were running it before passing a string like "asdfasdfsadfsa" it was evaluating #1 and finding 0 numbers. It then evaluated #2 and found 0 instances of a decimal with 2 or more numbers. Therefore the regexp was valid.

So instead, I split it into 2 circumstances:
[ol][li]/^([!](\d+(\.\d{1,2})?)[/!]|(\d*(\.\d{1,2}){1}))$/[/li]
[li]/^((\d+(\.\d{1,2})?)|[!](\d*(\.\d{1,2}){1})[/!])$/[/li]
[/ol]
Part #1 checks for 1 or more numbers followed by 0 or 1 instances of the decimal with 1 or 2 decimal places. #2 checks for 0 or more numbers with exactly 1 instance of a decimal with 1 or 2 decimal places. This way you will never encounter a string that passes for 0 instances of numbers preceding and following the decimal. It has to be one or the other (or both) in order to pass. Additionally, I added the beginning (^) and end ($) of string operators to ensure that a string like 1234.12asdf didn't pass.

-kaht

[small] <.[/small]
[banghead]

[small](He's back)[/small]

kaht · Mar 21, 2006

So did that fix it?

-kaht

[small] <.[/small]
[banghead]

[small](He's back)[/small]

arst06d · Mar 21, 2006

Sorry Kaht - had to leave the office at a rush last night.
Your solution works perfectly, and I appreciate your explanation of how it works.

Many thanks.

kaht · Mar 22, 2006

No problemo

-kaht

[small] <.[/small]
[banghead]

[small](He's back)[/small]

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regular expression 1

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