php/javascript question

[VJ]

Hello,

I'm building a website with an input form. The form has a lot of javascript checks, which display errormessages in dynamic html. These checks are performed onblur (for each field) and onsubmit (for the entire form, a function CheckForm is called).

Now, I would like to send the data to a PHP script.
I currently have action="sendmail.php", which directs to an error page and asks the user to press back to return to the form: all the dhtml errormessages are still show.

But, can I avoid the user having to press back by not redirecting to a new page if CheckForm says there are errors?
(If I redirect the user to the form page, the page reloads and the dhtml errormessages are not shown )

An option might be to have an onload function, which checks the referrer (how can I do this?). If the referrer is the php script: call CheckForm.

Bear in mind that the page is part of a Typo3 CMS, so I'm limited in sending parameters to pages.

Thanks!


Jorg

[VJ]

An option might be to have an onload function, which checks the referrer (how can I do this?). If the referrer is the php script: call CheckForm.

Ok, this seems to work...

Just for more customisation, can I set the referrer value in my PHP script?


Jörg

[dbdg]

Why are you sending the form to another page? wouldn't it just be better to validate and show the errors on the actual form page.

[VJ]

Why are you sending the form to another page? wouldn't it just be better to validate and show the errors on the actual form page.

It is the result of the submit button...

The validation and display of errors happens on the actual form page, but when one press the submit button, the php script is loaded. I found it the easiest to just use header(location: ...) to get back to the original form page.
Only problem is that it then needs to differentiate between loading normally (don't check for errors yet) and loading when returning from the php script (check for errors so that they are displayed in dhtml).

(I didn't really find how to only have the php script be called when there are no errors )


Jörg

[dbdg]

Add a get value into the url, not secure but it will get you started. Header could then be header("Location: page.php?Success=True");

On the php page you then check to see if the get value is set and whether or not it equals the expected response.

if(isset($_GET['Success']) && ($_GET['Success'] == True)) {

// What you want to happen on returning from the php script

} 

Or you could use one of the fields from $_SERVER to check for the referer. $_SERVER['HTTP_REFERER'] is not however consistant between user agents.

If you change the form action to <?php echo $_SERVER['PHP_SELF']; ?> the page could validate itself.

[VJ]

Add a get value into the url, not secure but it will get you started. Header could then be header("Location: page.php?Success=True");

On the php page you then check to see if the get value is set and whether or not it equals the expected response.

You mean as an alternative to using the referer to see how the user reaches this page?
(bear in mind: I'm a PHP newbie )

if(isset($_GET['Success']) && ($_GET['Success'] == True)) {

// What you want to happen on returning from the php script

} 

This goes in the body of the website, right?

Can I then simply call a javascript function?



Jörg

[dbdg]

You mean as an alternative to using the referer to see how the user reaches this page? (bear in mind: I'm a PHP newbie )

Yeah, you can use Referer but it isn't consistant. Problem with using a get value however is that anyone with any know how will see what you are doing.

Try Referer and see what happens, means you would check for

<?php if(isset($_SERVER['HTTP_REFERER']) && ($_SERVER['HTTP_REFERER'] == "nameofpage.php")) { ?>

This goes in the body of the website, right?

Can I then simply call a javascript function?

Can go where ever you want, if you need to output javascript or html you just drop out of php.

<?php if(isset($_GET['Success']) && ($_GET['Success'] == True)) { ?>

Standard javascript of html here
 
<?php } ?>

[jms]

Why would you submit the form if there are errors?

You are doing something like:

<form action="sendmail.php" onSubmit="return checkForm()">

right?

If the checkForm returns false, the form will not be submitted.

I think the cleanest would be to do all your error checking in the checkForm function, and not have some function called for each field with the onBlur handler.

Jan

[VJ]

<form action="sendmail.php" onSubmit="return checkForm()">

Well, it looks likes this:

<form name="form1" method="post" action="sendmail.php" onsubmit="return CheckForm()"  >

If the checkForm returns false, the form will not be submitted.

Nope: sendmail.php is called regardless of the returnvalue.

Ideally, I would want it to behave as you say: don't submit when there are errors (so no reload, no need t press a back button, ...) and submit when there aren't any errors.

Jörg

[jms]

Could you post your code?

[VJ]

Could you post your code?

I should still clean it up, but this is the function:

function CheckForm() {

	tempbool = CheckField('naam');
	tempbool = CheckField('voornaam') && tempbool;
	tempbool = CheckField('adres')  && tempbool;
	tempbool = CheckField('postnummer')  && tempbool;
	tempbool = CheckField('stad')  && tempbool;
	tempbool = CheckBevestigen(true) && tempbool;
	tempbool = CheckProdukten() && tempbool;
        tempbool = CheckDatum() && tempbool;

	if (document.getElementById('cookies').checked) {
		cookieForms('save', 'form1');
		}
	event.ReturnValue=tempbool;
		
}

I have tried adding 'return tempbool' at the end of the function, but it makes no difference.

Each of the CheckField functions returns values true or false.


Jörg

[VJ]

Here is the CheckField function (to give an idea). Fieldnames are in Dutch, as is the error message.

function CheckField(veld) {

s=document.getElementById(veld).value;
if (veld=='naam') document.getElementById('e_'+veld).innerHTML="naam"
  else if (veld=='voornaam') document.getElementById('e_'+veld).innerHTML="voornaam"
  else if (veld=='adres') document.getElementById('e_'+veld).innerHTML="adres"
  else if (veld=='postnummer') document.getElementById('e_'+veld).innerHTML="postnummer"
  else if (veld=='stad') document.getElementById('e_'+veld).innerHTML="stad"

if (s=='') { document.getElementById('e_'+veld).innerHTML+=" moet ingevuld worden"; return  false;} 
	  else { document.getElementById('e_'+veld).innerHTML="*"; return true;}
 return s;
}

Jörg

[VJ]

Just tested further: it is only in firefox that a return value false is ignored (and the sendmail script is called). In IE, everything goes as expected.


Jörg

[TnT]

I think the best way to do this is have the form submit to itself.

Check to see if a blank for is being displayed or errors exist and the form should be redisplayed.

If there are no errors then you can process the data.

[jms]

Here is the CheckField function (to give an idea). Fieldnames are in Dutch, as is the error message.

function CheckField(veld) {

s=document.getElementById(veld).value;
if (veld=='naam') document.getElementById('e_'+veld).innerHTML="naam"
  else if (veld=='voornaam') document.getElementById('e_'+veld).innerHTML="voornaam"
  else if (veld=='adres') document.getElementById('e_'+veld).innerHTML="adres"
  else if (veld=='postnummer') document.getElementById('e_'+veld).innerHTML="postnummer"
  else if (veld=='stad') document.getElementById('e_'+veld).innerHTML="stad"

if (s=='') { document.getElementById('e_'+veld).innerHTML+=" moet ingevuld worden"; return  false;} 
	  else { document.getElementById('e_'+veld).innerHTML="*"; return true;}
 return s;
}

Jörg

Are you sure that this function always will return true or false?

Also you should change Event.ReturnValue to only a standard return val. In any case you've prolly typed it wrong, it should be Event.returnValue (lowercase r).

Jan