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** Dynamically writing html/javascript from a javascript function **

P: n/a
I'm working on some code and am running into brick walls. I'm trying
to write out Javascript with Javascript and I've read the clj Meta FAQ
and didn't see the answer, read many similar posts (with no luck
though), and searched through the IRT.ORG Faqs
(www.irt.org/script/script.htm).

The Javascript is designed to open an popup window and then inside that
window call another script which will resize that window. There may be
another way around this but the reason I tried this approach initially
was that I wanted to call the onload handler in the popup window to
resize the image only after the image had completely loaded. I've had
some code in the primary Javascript file (showimage.js) before that
works if the image has been cached but on the first load, it doesn't
resize properly which tells me it is probably because it is trying to
resize the window based on the image size but it isn't completely known
at that point. So I removed that code and tried placing the resizing
code in the second Javascript file (resizewindow.js). BTW I've tried
other code to open a popup image and automatically size it ie Q1443 at
irt.org but that doesn't do exactly what we need.

Even if there is another way to do this with one file, I still want to
figure out why this isn't working in case I run into it in the future.

I thought what I would need to do to use document.writeln to write
Javascript would be to escape any special characters and to break
apart the script tag ie

document.writeln('<\/SCRIPT>');

would become

document.writeln('<\/SCR' + 'IPT>');

I have a HTML page and 2 Javascript files. All files are in the same
directory and have permissions set correctly.

Here are the 3 files (keep in mind wordwrap has jacked up the
formatting):

index.html
----------
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<SCRIPT type="text/javascript" LANGUAGE="JavaScript1.1"
SRC="showimage.js">
</SCRIPT>
</head>

<body>
Click the house<BR>
<A ONCLICK="newWindow1('house1.jpg','Nice House')"><IMG
SRC="house1thumb.jpg"></A>
</body>
</html>
showimage.js
------------
function newWindow1(pic,sitename)
{

picWindow=window.open('','','width=25,height=25,sc rollbars=1,resizable=1');
picWindow.document.writeln('<html> <head>');
picWindow.document.writeln('<SCR' + 'IPT type=\"text\/javascript\"
LANGUAGE=\"JavaScript1.1\" SRC=\"resizewindow.js\"><\/SCR' + 'IPT>');
picWindow.document.writeln('<\/head>');
picWindow.document.writeln('<body onload=\"resizewindow();\">');
picWindow.document.writeln('<img src=' + pic + '>');
picWindow.document.writeln('<\/body> <\/html>');
picWindow.document.close();
}

resizewindow.js
---------------
function resizewindow()
{
// Do resizing here.
// Right now this isn't being executed
alert("resizing window");
}
Can anyone provide some pointers as to why this javascript is failing?
I'm using IE6 on Win2k and when I click on the image to open the popup
window, it does open the window but it is white with no content and the
system immediately goes from about 4% CPU usage to 100% and
consistently stays there until I kill that window with the task
manager. I know I have something wrong in the code but I'm not sure
where. I appreciate any comments or tips. Thanks in advance.

cheers
Rob

Jul 23 '05 #1
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9 Replies

P: n/a
Robby Bankston wrote:
I'm working on some code and am running into brick walls. I'm trying
to write out Javascript with Javascript and I've read the clj Meta FAQ
and didn't see the answer, read many similar posts (with no luck
though), and searched through the IRT.ORG Faqs
(www.irt.org/script/script.htm).

The Javascript is designed to open an popup window and then inside that
window call another script which will resize that window. There may be
another way around this but the reason I tried this approach initially
was that I wanted to call the onload handler in the popup window to
resize the image only after the image had completely loaded. I've had
some code in the primary Javascript file (showimage.js) before that
works if the image has been cached but on the first load, it doesn't
resize properly which tells me it is probably because it is trying to
resize the window based on the image size but it isn't completely known
at that point. So I removed that code and tried placing the resizing
code in the second Javascript file (resizewindow.js). BTW I've tried
other code to open a popup image and automatically size it ie Q1443 at
irt.org but that doesn't do exactly what we need.

Even if there is another way to do this with one file, I still want to
figure out why this isn't working in case I run into it in the future.

I thought what I would need to do to use document.writeln to write
Javascript would be to escape any special characters and to break
apart the script tag ie

document.writeln('<\/SCRIPT>');

would become

document.writeln('<\/SCR' + 'IPT>');

I have a HTML page and 2 Javascript files. All files are in the same
directory and have permissions set correctly.

Here are the 3 files (keep in mind wordwrap has jacked up the
formatting):

index.html
----------
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<SCRIPT type="text/javascript" LANGUAGE="JavaScript1.1"
SRC="showimage.js">
</SCRIPT>
</head>

<body>
Click the house<BR>
<A ONCLICK="newWindow1('house1.jpg','Nice House')"><IMG
SRC="house1thumb.jpg"></A>
</body>
</html>
showimage.js
------------
function newWindow1(pic,sitename)
{

picWindow=window.open('','','width=25,height=25,sc rollbars=1,resizable=1');
picWindow.document.writeln('<html> <head>');
picWindow.document.writeln('<SCR' + 'IPT type=\"text\/javascript\"
LANGUAGE=\"JavaScript1.1\" SRC=\"resizewindow.js\"><\/SCR' + 'IPT>');
picWindow.document.writeln('<\/head>');
picWindow.document.writeln('<body onload=\"resizewindow();\">');
picWindow.document.writeln('<img src=' + pic + '>');
picWindow.document.writeln('<\/body> <\/html>');
picWindow.document.close();
}

resizewindow.js
---------------
function resizewindow()
{
// Do resizing here.
// Right now this isn't being executed
alert("resizing window");
}
Can anyone provide some pointers as to why this javascript is failing?
I'm using IE6 on Win2k and when I click on the image to open the popup
window, it does open the window but it is white with no content and the
system immediately goes from about 4% CPU usage to 100% and
consistently stays there until I kill that window with the task
manager. I know I have something wrong in the code but I'm not sure
where. I appreciate any comments or tips. Thanks in advance.

cheers
Rob

Hi Rob

I think you should use propper DOM methods if you want to render another
page. If you were to use propper DOM methods you won't have any issues
adding scripts to your pages. To this date I have never seen a REAL need
to use document.write("html"), except for maybe inline at render time,
there are always other ways.

And I don't understand why you are not loading a very simple html page
and then inserting the img once the popup html has loaded.

You might as well start with a blank canvas of html that you load in to
the new window when it opens. And get that pages onload to call a
funciton in the opener that loads the image and resizes the popup

-------------------- HTML -----------------
<html>
<head></head>
<body onload="opener.ChildLoaded(document)"></body>
</html>
-------------------------------------------
------------------ CODE -------------------

var cPic = "";
var picWindow = null;
function newWindow1(pic,sitename)
{
cPic = pic;
picWindow = window.open("URLtoSimpleHTML.url" ...... );
}

// this function will be called when it's loaded.
function ChildLoaded(doc)
{
// using proper DOM methods to create Elemnts
var eImg = doc.createElement("img");
eImg.onload = funciton ()
{
alert( this.width + " :: " + this.height );
// Do you resizing here on the global var
// picWindow.
}
doc.body.appendChild( eImg );
}

-------------------------------------------

HTH

Andy


Jul 23 '05 #2

P: n/a
Andrew Scott wrote:
Robby Bankston wrote:
I'm working on some code and am running into brick walls. I'm trying
to write out Javascript with Javascript and I've read the clj Meta FAQ
and didn't see the answer, read many similar posts (with no luck
though), and searched through the IRT.ORG Faqs
(www.irt.org/script/script.htm).

The Javascript is designed to open an popup window and then inside that
window call another script which will resize that window. There may be
another way around this but the reason I tried this approach initially
was that I wanted to call the onload handler in the popup window to
resize the image only after the image had completely loaded. I've had
some code in the primary Javascript file (showimage.js) before that
works if the image has been cached but on the first load, it doesn't
resize properly which tells me it is probably because it is trying to
resize the window based on the image size but it isn't completely known
at that point. So I removed that code and tried placing the resizing
code in the second Javascript file (resizewindow.js). BTW I've tried
other code to open a popup image and automatically size it ie Q1443 at
irt.org but that doesn't do exactly what we need.

Even if there is another way to do this with one file, I still want to
figure out why this isn't working in case I run into it in the future.

I thought what I would need to do to use document.writeln to write
Javascript would be to escape any special characters and to break
apart the script tag ie

document.writeln('<\/SCRIPT>');

would become

document.writeln('<\/SCR' + 'IPT>');

I have a HTML page and 2 Javascript files. All files are in the same
directory and have permissions set correctly.

Here are the 3 files (keep in mind wordwrap has jacked up the
formatting):

index.html
----------
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test</title>
<SCRIPT type="text/javascript" LANGUAGE="JavaScript1.1"
SRC="showimage.js">
</SCRIPT>
</head>

<body>
Click the house<BR>
<A ONCLICK="newWindow1('house1.jpg','Nice House')"><IMG
SRC="house1thumb.jpg"></A>
</body>
</html>
showimage.js
------------
function newWindow1(pic,sitename)
{

picWindow=window.open('','','width=25,height=25,sc rollbars=1,resizable=1');

picWindow.document.writeln('<html> <head>');
picWindow.document.writeln('<SCR' + 'IPT type=\"text\/javascript\"
LANGUAGE=\"JavaScript1.1\" SRC=\"resizewindow.js\"><\/SCR' + 'IPT>');
picWindow.document.writeln('<\/head>');
picWindow.document.writeln('<body onload=\"resizewindow();\">');
picWindow.document.writeln('<img src=' + pic + '>');
picWindow.document.writeln('<\/body> <\/html>');
picWindow.document.close();
}

resizewindow.js
---------------
function resizewindow()
{
// Do resizing here.
// Right now this isn't being executed
alert("resizing window");
}
Can anyone provide some pointers as to why this javascript is failing?
I'm using IE6 on Win2k and when I click on the image to open the popup
window, it does open the window but it is white with no content and the
system immediately goes from about 4% CPU usage to 100% and
consistently stays there until I kill that window with the task
manager. I know I have something wrong in the code but I'm not sure
where. I appreciate any comments or tips. Thanks in advance.

cheers
Rob

Hi Rob

I think you should use propper DOM methods if you want to render another
page. If you were to use propper DOM methods you won't have any issues
adding scripts to your pages. To this date I have never seen a REAL need
to use document.write("html"), except for maybe inline at render time,
there are always other ways.

And I don't understand why you are not loading a very simple html page
and then inserting the img once the popup html has loaded.

You might as well start with a blank canvas of html that you load in to
the new window when it opens. And get that pages onload to call a
funciton in the opener that loads the image and resizes the popup

-------------------- HTML -----------------
<html>
<head></head>
<body onload="opener.ChildLoaded(document)"></body>
</html>
-------------------------------------------
------------------ CODE -------------------

var cPic = "";
var picWindow = null;
function newWindow1(pic,sitename)
{
cPic = pic;
picWindow = window.open("URLtoSimpleHTML.url" ...... );
}

// this function will be called when it's loaded.
function ChildLoaded(doc)
{
// using proper DOM methods to create Elemnts
var eImg = doc.createElement("img");
eImg.onload = funciton ()
{
alert( this.width + " :: " + this.height );
// Do you resizing here on the global var
// picWindow.
}
doc.body.appendChild( eImg );
}

-------------------------------------------

HTH

Andy


Opps, Missed a line of code out...

function ChildLoaded(doc)
{
// using proper DOM methods to create Elemnts
var eImg = doc.createElement("img");
eImg.onload = funciton ()
{
alert( this.width + " :: " + this.height );
// Do you resizing here on the global var
// picWindow.
}

*******************************
eImg.src = cPic;
*******************************

doc.body.appendChild( eImg );
}

Sorry about that....

Andy
Jul 23 '05 #3

P: n/a
I use Javascript only occasionally and as such there are a lot of
things I don't know or have forgotten so I'm sure there are stupid
mistakes in not doing this properly and considering that much of this
is done late at night in a sleepy state, I'm sure errors abound.
Thanks for the input though. I'll try it out.

Jul 23 '05 #4

P: n/a
I'm still not sure why the original code bailed (inefficient as it
was), but Andrew's suggestions
worked perfectly. I'd still like to figure out the original problem
but his workaround was
more efficient, cleaner, and of course worked. Cheers.

Let me know and I'll send you some beer or coffee of your choosing.

Jul 23 '05 #5

P: n/a
Lee
Robby Bankston said:

I'm still not sure why the original code bailed (inefficient as it
was), but Andrew's suggestions
worked perfectly. I'd still like to figure out the original problem


You provided a relative path for your .js file, but since the window
was opened without an URL, there was no valid base for it to be
relative to.

Jul 23 '05 #6

P: n/a
"Robby Bankston" <va******@gmail.com> writes:
I'm working on some code and am running into brick walls. I'm trying
to write out Javascript with Javascript and I've read the clj Meta FAQ
and didn't see the answer, read many similar posts (with no luck
though), and searched through the IRT.ORG Faqs
(www.irt.org/script/script.htm). .... I thought what I would need to do to use document.writeln to write
Javascript would be to escape any special characters and to break
apart the script tag ie

document.writeln('<\/SCRIPT>');

would become

document.writeln('<\/SCR' + 'IPT>');
No need to split "<\/script>". The only thing that matters is the
sequence "</", which is already escaped ...
I have a HTML page and 2 Javascript files.
.... and that's only important for scripts inside HTML files. For
separate script files, you don't even need to avoid "</".

<SCRIPT type="text/javascript" LANGUAGE="JavaScript1.1"
Why JavaScript1.1? Do you know what the difference between version 1.1
and later versions is? Just drop the "language" attribute.
function newWindow1(pic,sitename)
"sitename" isn't used. Should it be the title of the window (remember,
the title element is required in valid HTML).
{

picWindow=window.open('','','width=25,height=25,sc rollbars=1,resizable=1');
picWindow.document.writeln('<html> <head>');
picWindow.document.writeln('<SCR' + 'IPT type=\"text\/javascript\"
LANGUAGE=\"JavaScript1.1\" SRC=\"resizewindow.js\"><\/SCR' + 'IPT>');
This could just be:
picWindow.document.writeln('<script type="text/javascript" src='resizewindow.js"><\/script>');

(and even without the "\" in "<\/" since it's in a separate js-file, but
it doesn't hurt to keep it as a habit)
picWindow.document.writeln('<\/head>');
picWindow.document.writeln('<body onload=\"resizewindow();\">');
picWindow.document.writeln('<img src=' + pic + '>'); Here you should have quotes around the URL:
picWindow.document.writeln('<img src="' + pic +'" alt="...">');

resizewindow.js
---------------
function resizewindow()
{
// Do resizing here.
// Right now this isn't being executed
alert("resizing window");
}
Try adding an alert at the top level here:
alert("resizewindow.js loaded!");
and see.
I'm using IE6 on Win2k and when I click on the image to open the popup
window, it does open the window but it is white with no content and the
system immediately goes from about 4% CPU usage to 100% and
consistently stays there until I kill that window with the task
manager.


Impressive. Sounds like a serious bug. Nothing I can see in the code
itself. Do you have any popup blockers?

/L
--
Lasse Reichstein Nielsen - lr*@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'
Jul 23 '05 #7

P: n/a
I tried using an absolute path as well but since that didn't work, I
just made it relative for brevity.

Since I have a workaround, it is only academic at this point but I'm
still interested in figuring
out this problem.

Thanks all.

Jul 23 '05 #8

P: n/a
I guess out of habit. Many of the examples I learned from in the
O'Reilly Javascript guide (3rd edition) use this attribute and I have
referenced this book many times so I guess it is out of habit.
Why JavaScript1.1? Do you know what the difference between version 1.1
and later versions is? Just drop the "language" attribute. "sitename" isn't used. Should it be the title of the window (remember,
the title element is required in valid HTML).
In the real code, it is used. For the purposes of the example, I
didn't
because it didn't seem relevant and I forgot to remove it from the
post.
This could just be:
picWindow.document.writeln('<script type="text/javascript" src='resizewindow.js"><\/script>');

(and even without the "\" in "<\/" since it's in a separate js-file, but
it doesn't hurt to keep it as a habit)
I'll keep that in mind.
Try adding an alert at the top level here:
alert("resizewindow.js loaded!");
and see.
I believe I tried that before but I'll try again.
Impressive. Sounds like a serious bug. Nothing I can see in the code
itself. Do you have any popup blockers?


I have the Google popup blocker for IE but it was disabled for the test
and I have
similar problems under Netscape or Firefox and I know the Netscape
browser doesn't
have any popup blockers installed. Come to think of it, I tried on IE
on a Windows
ME box also that didn't have any popup blockers and it did the same
thing.

Thanks.

Jul 23 '05 #9

P: n/a
my poor example...if the post doesn't kill it.. post your resize script
if you have problems...
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>Test</title>
<script type="text/javascript"><!--
function nW1(pic,sn){
picWindow=window.open('','','width=25,height=25,sc rollbars=1,resizable=1');
with(picWindow.document){
open();
write('<html><title>'+sn+'<\/title><head>\n'
+'<script type="text/javascript"><!-- \n'
+'function rsw(){\n'
+'window.moveTo(0,0);\n'
+'window.resizeTo(screen.availWidth,'
+'screen.availHeight);\n'
+'alert("resizing window");'
+'} //--><\/script>'
+'<\/head><body onload="rsw();">'
+'<img src="'+pic+'">'
+'<\/body><\/html>');
close();}} //--></script></head>
<body>Click the house<br>
<a onClick="nW1(''house1.jpg','Nice House')"><img
src="house1thumb.jpg"></a></body>
</html>

Jul 23 '05 #10

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