Example – Field Validation & Formatting

This example shows how to format and validate a US telephone number field on an Add or Edit screen layout.

The example involves a single field named tel_number. Data in the form of numbers entered into this field will automatically be formatted in the usual form of a telephone number in the USA. For example, entering the digits 1234567890 will result in a display of (123)456-7890. In addition, the function will not allow any non-numeric characters to be entered unless the user acknowledges that this is what they want.

To set up this requirement, take the following steps –

• Within the data dictionary, define the field TEL_NUMBER with a display type of Text Field
• Make sure you give these fields read and write permission
• Place this field on an Add screen layout. Add an HTML modifier to this field. The modifier value should be onkeypress=formatAsPhoneNumber(this);
• Place the following JavaScript functions within the UserJavaScript.js file.

  function chkNAN(char2chk)
  {
     var validNum = "0123456789";
     if (validNum.indexOf(char2chk) == "-1")
        return(confirm("You have entered a non-numeric 
                        character.\nDo you want to turn off non-
                        numeric character checking?"));
  }
  
  function formatAsPhoneNum(fld)
  {
     var isNamedFone = false;
     fldVal = fld.value;
  
     var tmpStr = "(";
     keyCount = fldVal.length;
     keyEntered =fldVal.substring(keyCount-1,keyCount);
  
     if (keyCount < 2)   isNamedFone = false;
     if (!isNamedFone)   isNamedFone = chkNAN(keyEntered);
  
     keyCount++;
     with (document.editForm)
     {
        switch (keyCount)
        {
           case 2:
              tmpStr +=  fldVal;
              fld.value = tmpStr;
              break;
           case 5:
              fld.value +=  ")";
              break;
            case 9:
              fld.value += "-"; 
              break;
        }
     }
  }

• When the user enters the telephone number in the field it will be validated, and the formatting applied to the number. If they enter an invalid character, they will see a dialog box with the message You have entered a non-numeric character. Do you want to turn off non-numeric character checking?