246197 - js error when I click on image with onclick parameter

Status: RESOLVED DUPLICATE of bug 246385

(Core :: DOM: Core & HTML, defect)

Description

[Pavel Novak]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8a2) Gecko/20040603 Firefox/0.8.0+
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8a2) Gecko/20040603 Firefox/0.8.0+

HTML page:
<form>
<input type="text" name="myNumber" value="0">
<img src="images/something.gif" alt="+" width="20" height="20" border="1" 
     onclick="myNumber.value = parseFloat(myNumber.value) + parseFloat(1)">
<button onclick="myNumber.value = parseFloat(myNumber.value) + parseFloat(1);
return false">+</button>
</form>

When I click on the button myValue is increased. But when I click on img it gets
into JS Console: "Error: myNumber is not defined". The same error when I use
image map instead img.

In Mozilla 1.6, Firefox 0.8, Konqueror 3.2 and IE 6 it's ok.

Reproducible: Always
Steps to Reproduce:
Just try my example.
Actual Results:  
JavaScript Error: "Error: myNumber is not defined"

Expected Results:  
Increase value "myNumber"

Comment 1

[timeless]

you need to use document.getElementById("myNumber") and have <input type="text"
id="myNumber" value="0">

your code does not follow the w3 way of doing things. this is not a bug.

Comment 2

[coolynx]

(In reply to comment #1)
> your code does not follow the w3 way of doing things. this is not a bug.

maybe it did not validate before, but now JavaScript Console popups every time
an error is found. i tried everything to disable it - no luck.

i played around these settings, but nothing works - still popups on error.
user_pref("javascript.console.open_on_error", false);
user_pref("javascript.classic.error_alerts", false);
user_pref("javascript.options.showInConsole", true);
user_pref("javascript.options.strict", true);

i think that console is a really powerful tool, but when it comes out every time
i click on some buggy js it gets annoying.

ff 0.9rc 20040609 build on windows

Comment 3

[coolynx]

Sorry for flooding but looks like my problem is related to this bug
http://bugzilla.mozilla.org/show_bug.cgi?id=213950
when a link has <a href="javascript:" url it opens a console.

Comment 4

[timeless]

please attach a testcase

Comment 5

[José Jeria]

No reply from reporter, marking as wfm

Please reopen if you can reproduce this with a nighty build and a fresh profile

Comment 6

[Pavel Novak]

(In reply to comment #5)  
> Please reopen if you can reproduce this with a nighty build and a fresh  
profile  
  
Yes, I can reproduce this with Gecko/20041113. 
 

Comment 7

[Pavel Novak]

Attachment: attach the testcase

Comment 8

[Gérard Talbot]

This bug is about the scope chain lookup for form controls. This bug 246197 is
case 3 at this page:
http://www.gtalbot.org/BugzillaSection/Bug253091.html

If you had used
document.forms[0].myNumber.value = parseFloat(myNumber.value) + parseFloat(1)
it would work in *all modern browsers*.
Even
document.forms[0].elements["myNumber"].value = parseFloat(myNumber.value) +
parseFloat(1)
would also work in a wide majority of browsers.

As mentioned by timeless, using an id and getElementById would also work. But
the W3C allowed form controls to use the name attribute otherwise it would not
be possible to send name and value pairs to the server.
http://www.jibbering.com/faq/faq_notes/form_access.html#faInC

So, there is definately a duplicate of this bug for sure... otherwise, I will
reactivate bug 253091..

Comment 9

[Gérard Talbot]

Bug 246385 was (is) a duplicate of this bug: same basic description, same
javascript console error message, same way to reference the button or form
control, same statement that previous Mozilla release had not this problem.

Comment 10

[Gérard Talbot]

In Internet Explorer, named form controls are visible in the global scope. This is wrong. 

If someone visits this bug, then (s)he can fix this problem by following timeless' recommendation in this bug's comment #1.

More info available on how to do this at:

Accessing Elements with the W3C DOM 
http://developer.mozilla.org/en/Using_Web_Standards_in_your_Web_Pages/Using_the_W3C_DOM#Accessing_Elements_with_the_W3C_DOM

Resolving as a DUPLICATE of bug 246385