simple error?

09-02-2005

Hello,

I am trying to print out the array values for a second time but get
error on page message?

Thanks

Geoff

<html>
<HEAD>

<SCRIPT language="JavaScript">
<!--
function display_questions()
{
var questions= new Array(5)
questions[0]="question 1";
questions[1]="question 2";
questions[2]="question 3";
questions[3]="question 4";
questions[4]="question 5";
var x=0;
for (x=0; x<5; x++)
{
document.write(questions[x] + "<br>");
}
document.write("<input type='button' value='again' onclick='again()' /
>");

}

function again()
{
var i=0;
for (i = 0; i<5; i++)
{
document.write(this.questions[i] + "<br>");
}

}
</SCRIPT>

</HEAD>
<BODY>

<input type="button" value="see questions"
onclick="display_questions()" />

</BODY>
</html>

09-02-2005

Hi Geoff,
The problem is when you did "document.write" you actually cleared
the function "again" itself. Thats why it complains "again is
notdefined".
Solutions:
1. Write "again" function again using document.write().
[OR]
2. Dont use document.write, instead write dynamically in a "div" or
"span".

- Peroli Sivaprakasam

Geoff Cox wrote:
> Hello,
>
> I am trying to print out the array values for a second time but get
> error on page message?
>
> Thanks
>
> Geoff
>
> <html>
> <HEAD>
>
> <SCRIPT language="JavaScript">
> <!--
> function display_questions()
> {
> var questions= new Array(5)
> questions[0]="question 1";
> questions[1]="question 2";
> questions[2]="question 3";
> questions[3]="question 4";
> questions[4]="question 5";
> var x=0;
> for (x=0; x<5; x++)
> {
> document.write(questions[x] + "<br>");
> }
> document.write("<input type='button' value='again' onclick='again()' /
> >");
>
> }
>
> function again()
> {
> var i=0;
> for (i = 0; i<5; i++)
> {
> document.write(this.questions[i] + "<br>");
> }
>
> }
> </SCRIPT>
>
> </HEAD>
> <BODY>
>
> <input type="button" value="see questions"
> onclick="display_questions()" />
>
>
> </BODY>
> </html>

09-02-2005

On 2 Sep 2005 01:57:24 -0700, "Peroli" <> wrote:

>Hi Geoff,
> The problem is when you did "document.write" you actually cleared
>the function "again" itself. Thats why it complains "again is
>notdefined".
>Solutions:
>1. Write "again" function again using document.write().
>[OR]
>2. Dont use document.write, instead write dynamically in a "div" or
>"span".

Peroli,

Could you please give me an idea what you mean by the second option?!

Cheers

Geoff

09-02-2005

Geoff Cox <> writes:

> I am trying to print out the array values for a second time but get
> error on page message?

What error message do you get? (If you use IE, you should enable
error messages when doing development).

> <SCRIPT language="JavaScript">

Should be <script type="text/javascript">

> <!--

Not necessary.

> function display_questions()
> {
> var questions= new Array(5)

Here "questions" is declared as a local variable inside the
"display_questions" function. The "questions" variable is only
visible inside this function.

> document.write("<input type='button' value='again' onclick='again()' /
>>");

You seem to be trying to document.write an XHTML element (the closing
"/>" looks like XHTML), but document.write generally doesn't work
for XHTML pages parsed as such.

Anyway, when this button is clicked, the again function is called.

> function again()
> {
> var i=0;
> for (i = 0; i<5; i++)

A little shorter:
for (var i = 0; i < 5; i++)

> {
> document.write(this.questions[i] + "<br>");

This is called through a user click on a button. That suggests that the
page is already done loading when this is called. Doing "document.write"
on a page after it has finished loading will erase the entire page, and
replace it with what is written.

Also, the "this" operator refers to the global object (aka "window"),
which doesn't have a "questions" property.

> <input type="button" value="see questions"
> onclick="display_questions()" />

And this calls the first function, which also erases the page.

Generally, document.write is not the way to add content to a page
that is already loaded. There are different ways to do that, either
through the W3C DOM or using the proprietary "innerHTML" property.
<URL:http://jibbering.com/faq/#FAQ4_15>

/L
--
Lasse Reichstein Nielsen -
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'

09-02-2005

On Fri, 02 Sep 2005 17:36:16 +0200, Lasse Reichstein Nielsen
<> wrote:

>Generally, document.write is not the way to add content to a page
>that is already loaded. There are different ways to do that, either
>through the W3C DOM or using the proprietary "innerHTML" property.
><URL:http://jibbering.com/faq/#FAQ4_15>

Lasse,

Thanks for your comments - how does using

"<div ID='"d_name">data</div>"

work when I try to write out the 5 array values?

Cheers

Geoff

09-02-2005

Geoff Cox wrote:
> On Fri, 02 Sep 2005 17:36:16 +0200, Lasse Reichstein Nielsen
> <> wrote:
>
>
> >Generally, document.write is not the way to add content to a page
> >that is already loaded. There are different ways to do that, either
> >through the W3C DOM or using the proprietary "innerHTML" property.
> ><URL:http://jibbering.com/faq/#FAQ4_15>
>
> Lasse,
>
> Thanks for your comments - how does using
>
> "<div ID='"d_name">data</div>"
>
> work when I try to write out the 5 array values?
>
> Cheers
>
> Geoff

Hi Geoff,

This is how it would work:

function display_questions()
{
var questions= new Array(5)
questions[0]="question 1";
questions[1]="question 2";
questions[2]="question 3";
questions[3]="question 4";
questions[4]="question 5";

var str_questions = "";

for (var i=0; i < question.length; ++i)
{
str_questions += questions[i] + "<br>";
}

document.getElementById("d_name").innerHTML = str_questions;
}

OR even better yet, take the following shortcut if all you're doing is
adding the same string at the end.

function display_questions()
{
var questions= new Array(5)
questions[0]="question 1";
questions[1]="question 2";
questions[2]="question 3";
questions[3]="question 4";
questions[4]="question 5";

var output = questions.join("<br>");

document.getElementById("d_name").innerHTML = output;
}
Hope this helps.

09-02-2005

On Fri, 02 Sep 2005 08:00:07 GMT, Geoff Cox
<> wrote:

web dev

Many thanks for your reply. I have tried the first approach and that
works fine but probably better now if I try to explain what I am
trying to do!

The code below works OK up to a point but the function saveIt2() is
wrong and my original post was supposed to help me understand why!

The aim is to present an image and a series of questions which the
user answers by positioning the slider. I want to put the slider value
into an array and then when the last question has been answered the
next click of the Next button will send the array values to me by
email. To try to simplify things I am just trying to print out the
array values using saveIt2(().

Can you see what is going wrong with saveIt2()?

Cheers

Geoff

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<HEAD>

<link rel=stylesheet href="slider.css" type="text/css">
<SCRIPT SRC="slider.js"></SCRIPT>
<SCRIPT SRC="prototype-1.3.1.js"></SCRIPT>

<SCRIPT>

var mySlider1 = new Slider( "Slider1" );

var count = 0;
var slider_value = new Array(5)

mySlider1.leftValue = 0;
mySlider1.rightValue = 10;
mySlider1.defaultValue = 0;

mySlider1.offsetX = 1;
mySlider1.offsetY = 1;
mySlider1.maxSlide = 258;

mySlider1.onmouseover = "self.status='Try me!'";
mySlider1.onmousedown = "self.status='You start
at'+this.getValue(0)";
mySlider1.onmouseup = "self.status='You end at '+this.getValue(0)";
mySlider1.onchange = "self.status='The current value
is'+this.getValue(0)";
mySlider1.onclick = "this.setValue(this.defaultValue)";

mySlider1.onchange
="document.getElementById('Slider1ValueText').inne rHTML
=''+this.getValue(0)";

var lhs_questions = new Array(5)
lhs_questions[0]="LHS question 1";
lhs_questions[1]="LHS question 2";
lhs_questions[2]="LHS question 3";
lhs_questions[3]="LHS question 4";
lhs_questions[4]="LHS question 5";

var rhs_questions = new Array(5)
rhs_questions[0]="RHS question 1";
rhs_questions[1]="RHS question 2";
rhs_questions[2]="RHS question 3";
rhs_questions[3]="RHS question 4";
rhs_questions[4]="RHS question 5";

function buildTable()
{
document.write("<center>");
document.write("<table border='2'>");
document.write("<tr>");
document.write(" <td ID='lhs_question'>" + this.lhs_questions[0] +
"</td>");
document.write(" <td>" + "<IMG SRC='sliderbg.gif'
NAME='Slider1RailImg' ID='Slider1RailImg'>" + "</td>");
document.write(" <td ID='rhs_question'>" + this.rhs_questions[0] +
"</td>");
document.write("</tr>");
document.write("</table>");
document.write("</center>");
}

function next_question()
{
slider_value[count] = this.mySlider1.getValue(0);
this.count++;

if (this.count < 5)
{
document.getElementById('lhs_question').innerHTML =
this.lhs_questions[count];
document.getElementById('rhs_question').innerHTML =
this.rhs_questions[count];
} else
{
saveIt2();
}
}
function saveIt()
{
var url = 'http://path/formmail.cgi';
var pars =
'sliderVal='+document.getElementById('Slider1Value Text').innerHTML;
var myAjax = new Ajax.Updater('Status', url, {method: 'post',
parameters: pars});

}

function saveIt2()
{
for (var i = 0; i <5; i++)
{
document.write(this.slider_value[i] + "<br>");
}
}

</script>

</HEAD>

<BODY onLoad="mySlider1.placeSlider()">

<h2 align="center">Social Group</h2>

<p align="center"><img src="pic3.jpg"></p>

<script language="javascript"
type="text/javascript">buildTable();</script>

<center>
<table>
<tr>
<td colspan="3" align="center">
<input type="button" value="Next" onclick="next_question()" />

<SPAN class="invisible" ID="Slider1ValueText"></SPAN>
<SPAN ID="Status"></SPAN></td></tr>

</TABLE>
</center>

<SCRIPT>

mySlider1.writeSlider();

</SCRIPT>

</body>
</html>

09-03-2005

hi Geoff,

>
> function saveIt2()
> {
> for (var i = 0; i <5; i++)
> {
> document.write(this.slider_value[i] + "<br>");
> }
> }
>

Again the problem is with document.write(). Please avoid it if you
don't know what you are doing. Try writing in a new "div" or "span".

[UNTESTED]
<div id="mydiv"></div>

function saveIt2()
{
for (var i = 0; i <5; i++)
{
document.getElementById('mydiv').innerHTML += this.slider_value[i] +
"<br>";
}
}

- Peroli Sivaprakasam

09-03-2005

On 3 Sep 2005 00:24:35 -0700, "Peroli" <> wrote:

> Again the problem is with document.write(). Please avoid it if you
>don't know what you are doing. Try writing in a new "div" or "span".
>
>[UNTESTED]
><div id="mydiv"></div>
>
>function saveIt2()
>{
> for (var i = 0; i <5; i++)
> {
> document.getElementById('mydiv').innerHTML += this.slider_value[i] +
>"<br>";
> }
>}

Thanks Peroli - think I will get the O'Reilly Book on JavaScript -
seems to be well thought of?

Cheers

Geoff

>
>- Peroli Sivaprakasam

09-03-2005

On 3 Sep 2005 00:24:35 -0700, "Peroli" <> wrote:

Peroli,

I have used your code but for some reason I am getting the last value
of the array repeated at the beginning in the dat sent via email - can
you see why?

Geoff

function saveIt()
{
for (var i = 0; i < slider_value.length; ++i)
{
document.getElementById("Slider1ValueText").innerH TML +=
this.slider_value[i] + " ";
}

var situation = "Social Group";
var url = 'http://website/path/cgi-bin/formmail-nms2.cgi';
var pars = 'Situation: ' + situation + ' ' + 'Name: ' + name + ' ' +
'Slider_Values='+document.getElementById('Slider1V alueText').innerHTML;
var myAjax = new Ajax.Updater('Status', url, {method: 'post',
parameters: pars});
}

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