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form validation (text area)

Posted on 2003-12-05
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Last Modified: 2010-03-31
Can data validation be done when the number of text entries is unknown?

I have a form where the number of text boxes is created by the number of destinations entered on the previous jsp.  Is there a way to do JavaScript to make sure data is entered into the textbox when I don’t know how many I will have?  I am using a JavaBean on the first JSP but not on the second.  On the second jsp I just want to make sure the text box is not blank.

<code>

  String numDest = fltReqInfo.getNumDest();
  int i = Integer.valueOf(numDest).intValue();   //number of destinations
  int j;       //loop counter
  String prompt = "";   //propmt string for desired city
  String cityPrompt = "";   //prompt for text box name

<table border="0">
<%
  for (j=1;j<=i;j++)
  {
  if (j==1)
  {
    prompt = "Starting City";
  }
  else if (j==i)
  {
    prompt = "Final City";
  }
  else
  {
    prompt = "City " + j;
  }
  cityPrompt = "city" + j;
%>
<tr>
  <td><%= prompt%></td>
  <td><input type="text" name="<%= cityPrompt %>" value="" size="30" maxlength="30" /></td>

</table>

                 <center>
                    <input type="submit" name="butNext"
                    value="Submit" /> <input type="Reset" />
                  </center>

</form>
</code>
0
Comment
Question by:wykzimme
  • 3
5 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 9883274
You could name each text box starting with 'tb' for instance. Loop through the form elements and test each one for null or empty content
0
 
LVL 92

Expert Comment

by:objects
ID: 9884833
> Is there a way to do JavaScript to make sure data is entered

Your javascript is being generated by the same jsp page so you can include the number of fields.

If you are processing the form data on the server then add a hidden variable storing the number of fields.
0
 
LVL 3

Expert Comment

by:applekanna
ID: 9886830
//function to check if field value is entered or not
function validRequired(formField,fieldLabel)
{
  var result = true;
  if (formField.value == "")
  {
    alert('Please enter a value for the "' + fieldLabel +'" field.');
    formField.focus();
    result = false;
  }
  return result;
}


function validateForm(theForm)
{
  // Customize these calls for your form
for(int i = 0;i < theForm.length ; i++)
  if (!validRequired(theForm.name[i], theForm.name[i].value))
    return false;

   return true;
}

call this from the form as

<form name = "formA"  method = "post" action = "jsp3.jsp" onsubmit="return validateForm(this)">
</form>

Hope this helps . basically you give the JS the form name and ask it to check all fields.
Customize accroding to your needs.
Cheers!
0
 
LVL 86

Accepted Solution

by:
CEHJ earned 50 total points
ID: 9888222
Try something like this in your form's onsubmit:

function validateTextFields() {
      for(i=0;i<document.forms.length;i++){
            for(j=0;j<document.forms[i].elements.length;j++){
                  var formObj=document.forms[i].elements[j];
                  if(formObj.type.toLowerCase() == "text") {
                        if (formObj.value == "") {
                              alert("Blank text field(s) found");
                              return false;
                        }
                  }
            }
      }
      return true;
}        

0
 
LVL 86

Expert Comment

by:CEHJ
ID: 9900053
8-)
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