Problems with ASP.Net object and Javascript

[tshad]

I have a function:

function SalaryDisplay(m e)
{
var salaryMinLabel = document.getEle mentById("Salar yMin");
salaryMinLabel. value = 200;
alert("after setting salaryMinLabel = " + salaryMinLabel. value);
}

I also have an asp.net object:

<asp:label id="SalaryMin" runat="server" />

Which renders into:

<span id="SalaryMin"> </span>

The function seems to find the span fine. The alert box shows that it is
set to 200. But the web page never shows it.

Is there a problem setting the span element?

Thanks,

Tom

[Lasse Reichstein Nielsen]

Ivan Marsh <an*****@you.no w> writes:

There exist bugs in the JavaScript and JScript implementations that
make them non-compliant.

Being non-compliant isn't a bug.

But claiming to be compliant and not being it, suggests that the
noncompliance is due to a bug, not a deliberate choice.

It should be noticed that JScript is not claimed to be compliant:
<URL:http://msdn.microsoft. com/library/en-us/script56/html/js56jsconabout. asp>

Rhino and SpiderMonkey do claim compliance:
<URL:http://www.mozilla.org/js/>

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

[Thomas 'PointedEars' Lahn]

Jim Ley wrote:

[...] Thomas 'PointedEars' Lahn [...] wrote:

Jim Ley wrote:

[...] Richard Cornford [...] wrote:
Thus they are all conforming ECMAScript implementations .
Well there are bugs...

Please be more specific. <------------------------------------------.

|
There exist bugs in the JavaScript and JScript implementations that |
make them non-compliant. |

|
----------------------------------------------------------------------'
PointedEars
--
In the First World War, 13 million people were killed. In the Second
World War, 40 million people were killed. I think that if a third war
takes place, nothing is going to be left on the face of earth.
-- Shakira, 2003-02-05 @ MTV.com

[Richard Cornford]

Jim Ley wrote:

Richard Cornford wrote:

Thus they are all conforming ECMAScript
implementatio ns.

Well there are bugs...

Fair enough, they all have minor behaviour that does not strictly
conform with the what is specified in ECMA 262. But it is not the
extensions that are getting in the way of that.

Ricahrd.

[Lasse Reichstein Nielsen]

Thomas 'PointedEars' Lahn <Po*********@we b.de> writes:

Jim Ley wrote:

[...] Thomas 'PointedEars' Lahn [...] wrote:

Jim Ley wrote:
[...] Richard Cornford [...] wrote:
> Thus they are all conforming ECMAScript implementations .
Well there are bugs...
Please be more specific. <------------------------------------------.

|
There exist bugs in the JavaScript and JScript implementations that |
make them non-compliant. |

|
----------------------------------------------------------------------'

Take arrays, a quite fundamental part of the language:

In IE:
[1,2,3,].length
is 4, it should be 3.

In FireFox:
"1" in [0,,2]
is true, should be false.

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

[Andrew Poulos]

>>>>>>Thus they are all conforming ECMAScript implementations .

>
>Well there are bugs...

Please be more specific. <------------------------------------------.

There exist bugs in the JavaScript and JScript implementations that |
make them non-compliant.

Take arrays, a quite fundamental part of the language:

In IE:
[1,2,3,].length
is 4, it should be 3.

In FireFox:
"1" in [0,,2]
is true, should be false.

If I do this with FF 1.02:

var my = [0,,2];
if ( my[1] ) alert('true');
else alert('false');

it displays 'false'
Andrew Poulos

[Thomas 'PointedEars' Lahn]

Andrew Poulos schrieb:

>>> Thus they are all conforming ECMAScript implementations .

[...]
In FireFox:
"1" in [0,,2]
is true, should be false.

If I do this with FF 1.02:

var my = [0,,2];
if ( my[1] ) alert('true');
else alert('false');

it displays 'false'

I think this was about the `in' operation.
PointedEars

P.S.
Please provider proper attribution.

[Thomas 'PointedEars' Lahn]

Lasse Reichstein Nielsen schrieb:

Ivan Marsh <an*****@you.no w> writes:

There exist bugs in the JavaScript and JScript implementations
that make them non-compliant.

Being non-compliant isn't a bug.

But claiming to be compliant and not being it, suggests that the
noncompliance is due to a bug, not a deliberate choice.

It should be noticed that JScript is not claimed to be compliant:
<URL:http://msdn.microsoft.com/library/en...html/js56jscon
about.asp>

Rhino and SpiderMonkey do claim compliance:
<URL:http://www.mozilla.org/js/>

IBTD:

"with only minor exceptions ..., ... a full implementation" (M$) and
"a superset ... with mild differences" (Mozilla.org) is much the same
to me.
PointedEars

[Lasse Reichstein Nielsen]

Andrew Poulos <ap*****@hotmai l.com> writes:

Take arrays, a quite fundamental part of the language: ..... In FireFox:
"1" in [0,,2]
is true, should be false.

If I do this with FF 1.02:

var my = [0,,2];
if ( my[1] ) alert('true');
else alert('false');

it displays 'false'

As it should.

The "in" operator takes a string and an object, and gives true
if the object has a property with the name in string. E.g.

var o = {foo:42};
alert(["foo" in o, "bar" in o]);

It alerts "true,false ".

An object might have a property with a value that is "falsey" (converts
to false as a boolean), even "undefined" .

var o = {foo: undefined};
alert(["foo" in o, "bar" in o]);
alert([o["foo"],o["bar"]]);

alerts first "true,false ", then "undefined,unde fined".

There is a difference between not having the property, and having the
property with the value "undefined" , even if attempting to read either
gives the same result (undefined).
The array literal [0,,2] should not have a property called "1"
according to the ECMAScript standard. The error in FireFox/Gecko's
ECMAScript implementation is that that it does, it just has the value
"undefined" . It's a very minor and insignificant error, which is
probably why it hasen't been fixed, but it *is* an error.

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

[Lasse Reichstein Nielsen]

"Thomas 'PointedEars' Lahn" <Po*********@we b.de> writes:

IBTD:

"with only minor exceptions ..., ... a full implementation" (M$) and
"a superset ... with mild differences" (Mozilla.org) is much the same
to me.

Yes, but the Mozilla page also says "Like SpiderMonkey, Rhino is
ECMA-262 Edition 3 compliant.". However vague they are in other
places, that line is either too clear to misinterpret. It might be
wrong, but it's not ambiguous :)

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

[Thomas 'PointedEars' Lahn]

Lasse Reichstein Nielsen wrote:

The array literal [0,,2] should not have a property called "1"
according to the ECMAScript standard. [...]
Yes, it should. As of ECMAScript 3, Subsection 11.1.4 (Array Initialiser),
`[0,,2]' is the literal notation of an Array object with the following
structure and content (written as an object literal):

{"0": 0,
"1": undefined, // which is why its value converted to `false'
"2": 2,
// following other Array object specific properties like `length';
// from now on: `...'
}

The productions are:

ArrayLiteral :
[ Elision_opt ]
[ ElementList ]
[ ElementList , Elision_opt ]

ElementList :
Elision_opt AssignmentExpre ssion
ElementList , Elision_opt AssignmentExpre ssion

Elision :
,
Elision ,

"[0,,2]" can be produced by

ArrayLiteral
=> [ ElementList ]
=> [ ElementList , Elision_opt AssignmentExpre ssion ]
=> [ Elision_opt AssignmentExpre ssion , Elision_opt AssignmentExpre ssion ]
=> [ AssignmentExpre ssion , Elision_opt AssignmentExpre ssion ]
=> ...
=> [ 0 , Elision_opt 2 ]
=> [ 0 , , 2 ]

and is therefore evaluated as follows:

...
[ ElementList , Elision_opt AssignmentExpre ssion ]
| 1. Evaluate ElementList.
Evaluate production `ElementList : Elision_opt AssignmentExpre ssion'
| 1. Create a new array as if by the expression new Array().
=> {...} == []
| 2. Evaluate Elision; if not present, use the numeric value zero.
=> 0
| 3. Evaluate AssignmentExpre ssion.
=> 0
| 4. Call GetValue(Result (3)).
=> 0
| 5. Call the [[Put]] method of Result(1) with arguments Result(2)
| and Result(4).
=> [].[[Put]](0, 0)
=> {"0": 0, ...} == [0]
| 6. Return Result(1)
=> [0]

| 2. Evaluate Elision; if not present, use the numeric value zero.
Evaluate production `Elision : ,'
| 1. Return the numeric value 1.
=> 1

| 3. Evaluate AssignmentExpre ssion.
=> 2

| 4. Call GetValue(Result (3)).
=> 2

| 5. Call the [[Get]] method of Result(1) with argument "length".
=> [0].[[Get]]("length")
=> 1

| 6. Call the [[Put]] method of Result(1) with arguments
| (Result(2)+Resu lt(5)) and Result(4).
=> [0].[[Put]](1+1, 2)
=> [0].[[Put]](2, 2)

| 8.6.2.2 [[Put]] (P, V)
|
| 1. Call the [[CanPut]] method of O with name P.
=> true
| 2. If Result(1) is false, return.
| 3. If O doesn?t have a property with name P, go to step 6.
| [...]
| 6. Create a property with name P, set its value to V and give
| it empty attributes.
| 7. Return.

Now you assume that step 6.6. results in an object with the following
structure and content:

{"0": 0,
"2": 2,
...
}

However, ECMAScript 3 also states:

| 11.1.4 Array Initialiser
| [...]
| Array elements may be elided at the beginning, middle or end of the
| element list. Whenever a comma in the element list is not preceded
| by an AssignmentExpre ssion (i.e., a comma at the beginning or after
| another comma), the missing array element contributes to the length
| of the Array and increases the index of subsequent elements.
| Elided array elements are not defined.

Since in "[0, , 2]", the second "comma in the element list is not preceded
by an AssignmentExpre ssion", to be exact, is "a comma [...] after another
comma", "the missing array element ..." [continue reading above]. And so:

| 7. Return Result(1)
=> [0, undefined, 2]

The `in' operation returns `true' if/while the second operand has a
property named as the first operand; since that property ("1") exists
here, it returns `true'. (The property's value does not matter, as
you just explained.)
The error in FireFox/Gecko's ECMAScript implementation is that that
it does, it just has the value "undefined" .

It is not an error :)
PointedEars