JavaScript/PHP problem.

gazchap

This is more of a problem with JavaScript than PHP, but I'm hoping someone here knows how to solve this particular puzzle 🙂

I've got a form with six rows (this isn't fixed though) of three radio buttons on it.

The three radio buttons on each row are named as "meal[x]" in the HTML, where x is a number from 1 to 6 (or however many rows there are)

Each radio button on the row has a different value associated with it in the HTML - B, L, and BL.

Whenever one of these radio buttons is checked, I need to be able to scan through ALL of the radio buttons on the page and calculate the sub-total for the order based on the radio buttons.

However, because I'm using "meal[x]" as the name, JavaScript doesn't seem to want to go through them all. Here's the code:

function calculateTotals() {
	subtotal=0;
	for(i=1; i<=<?=$num_delegates?>; i++){
		switch (document.elements['meal['+eval(i)+']'].value){
			case "B":
				subtotal = subtotal + <?=MEAL_BREAKFAST?>;
				break;
			case "L":
				subtotal = subtotal + <?=MEAL_LUNCH?>;
				break;
			case "BL":
				subtotal = subtotal + <?=MEAL_BOTH?>;
				break;
		}
		document.elements['sub_total_td'].innerHTML = "&pound; "+subtotal;
	}
}

Any help at all is greatly appreciated, guys 🙂

paulnaj

The form will only send the value of the selected radio button, so I don't see anyway for the server script to be involved ... got to be a javascript thing, as you say.

One way to solve this is to add a hidden field on the form containing the radio buttons that gets updated every time the user clicks a radio.

Here's a template form and javascript to play about with.

<html>
<head>
<title>Untitled</title>
</head>

<body>
<form action="checkbox_test.php" name="frm">
<input type="radio" name="fred" value="1" onClick="setTotal(this)">Fred 1
<input type="radio" name="fred" value="2" onClick="setTotal(this)">Fred 2
<input type="submit">
</form>
<script language="JavaScript" type="text/javascript">
function setTotal(rad){
var selectedValue = rad.value;
var f = document.frm;
var e = f.elements;
var total = 0;
for(var i = 0; i < e.length; i++){
if(e.type == "radio"){
// Do something
total += parseFloat(e.value);
}
}
alert(total);
}
</script>
</body>
</html>

Here's a corres. php response

<?php
echo "<hr>\$GET[\"fred\"] = ".$GET["fred"];
echo "<hr>\$GET[\"total\"] = ".$GET["total"];
?>

nelustr

So...
My first observation: you are using a wrong syntax for calling the PHP variables: <?=MEAL_BREAKFAST?>;
The correct one is: <?=($php_variable)?>
Second one: Do not try to include php variables in JS. It doesn't work in this manner. You can use JS embeded like this:

<?php
if ($condition){
  ....
// your code here
?>

<SCRIPT>...
.....
</SCRIPT>
<?php>
// your code here

}
?>

Third: You can pass variables between PHP an JS using:
<INPUT TYPE="hidden" NAME="variable" VALUE="<?=($php_variable")?>"> or using input type text having display: none

Anyway, the script (full PHP) showned below work fine ( http://www.xtrax.ro/php/test1.php )

<form method="POST">
<table align="center" border="1">
<?php
$nTables=6;
$needBreakfast=0;
$needLunch=0;
$needBoth=0;
$needNothing=0;
for ($iTables=1;$iTables<=$nTables;$iTables++){
//    echo "Table no. $iTables :".$meal[$iTables]."<BR />"; 
		switch ($meal[$iTables]){
    	 case "MEAL_BREAKFAST" : {$isBreakfast[$iTables]="checked"; $needBreakfast=$needBreakfast+1; break;}
       case "MEAL_LUNCH"     : {$isLunch[$iTables]    ="checked"; $needLunch    =$needLunch+1;     break;}
       case "MEAL_BOTH"      : {$isBoth[$iTables]     ="checked"; $needBoth     =$needBoth+1;      break;}
	     default               : {$isReleased[$iTables] ="checked"; $needNothing=$needNothing+1;}
			 }
	  }
for ($iTables=1;$iTables<=$nTables;$iTables++){
    echo "<tr>\n";
	  echo "<td align=\"center\">Table $iTables</td>\n";
    echo "<td align=\"center\">Breakfast<input type=\"radio\" name=\"meal[$iTables]\" value=\"MEAL_BREAKFAST\" onClick=\"submit()\" $isBreakfast[$iTables]></td>\n";
    echo "<td align=\"center\">Lunch    <input type=\"radio\" name=\"meal[$iTables]\" value=\"MEAL_LUNCH\"     onClick=\"submit()\" $isLunch[$iTables]></td>\n";
    echo "<td align=\"center\">Both     <input type=\"radio\" name=\"meal[$iTables]\" value=\"MEAL_BOTH\"      onClick=\"submit()\" $isBoth[$iTables]></td>\n";	 
    echo "<td align=\"center\">Release  <input type=\"radio\" name=\"meal[$iTables]\" value=\"MEAL_RELEASE\"   onClick=\"submit()\" $isReleased[$iTables]></td>\n";
    echo "</tr>\n";
		}
echo "<tr>\n";
echo "<td align=\"center\" rowspan=\"2\"><B>Total:</B></td>\n";
echo "<td align=\"center\"><B>$needBreakfast</B></td>\n";
echo "<td align=\"center\"><B>$needLunch</B></td>\n";
echo "<td align=\"center\"><B>$needBoth</B></td>\n";
echo "<td align=\"center\"><B>$needNothing</B></td>\n";
echo "</tr>\n";
?>
</table>
</form>

paulnaj

nelustr said ...

My first observation: you are using a wrong syntax for calling the PHP variables: <?=MEAL_BREAKFAST?>;

... but gazchap could have made these constants using the define() function.

nelustr

I "said":

My first observation: you are using a wrong syntax for calling the PHP variables: <?=MEAL_BREAKFAST?>;
The correct one is: <?=($php_variable)?>

paulnaj nelustr said ...

quote:

My first observation: you are using a wrong syntax for calling the PHP variables: <?=MEAL_BREAKFAST?>;

... but gazchap could have made these constants using the define() function.

Thanks! Could be or not

I just said that the syntax can be wrong. Nothing more.

And FYI, did you read the next statements:

Second one: Do not try to include php variables in JS. It doesn't work in this manner. You can use JS embeded like this:
....

So, I think that a new thread like "JS versus PHP" or "PHP versus JS) can help.

Best regards,

Nelu