[Javascript] [solved ]Object Not Defined "isDefined" & "readFrom "method

[Terry Riegel]

Duh.

Thanks,

Terry

Sent from my iPhone

On Nov 21, 2011, at 5:32 PM, Troy III Ajnej <trojani2000 at hotmail.com> wrote:

>
> *Your error - not Safari's* - no need to dupe it.
>
> Arguments of the function should be passed as strings - not as an already established fact of an arbitrarily
> existing object!
>
> You are presuming  that a.b.c.d.e.f object exists without any doubt;
> Than, for what reason would you be using the "isDefined" method anyway?!
>
> [No it shouldn't return a "boolean", that not the issue. My original "isDefined" returns
> boolean -but now I see - that it's not pragmatic and weakens the code efficiency when
> using it. ]
>
> No function can receive an undefined argument without causing an error;
> you can't .getlEmentById( title );  -  you need to, either pass it as a string literal,
> or (in this case) a string object. 'No alternative.
>
> There's no way you can pass a chain of some plain symbols as a function argument.
>
>
>
> The correct syntax is:
>
>    isDefined( "a.b.c.d.e.f" );
> Cheers, if you've already acknowledged it.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Troy III
> progressive art enterprise
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
> ----------------------------------------
>> From: riegel at clearimageonline.com
>> Date: Mon, 21 Nov 2011 16:28:22 -0500
>> To: javascript at lists.evolt.org
>> Subject: Re: [Javascript] [solved ]Object Not Defined "isDefined" & "read>From "method
>>
>> Troy,
>>
>> As I think about it "isDefined" should return a boolean. Your function doesn't do that and it returns an error in Safari
>>
>> Try this to duplicate it from the console...
>>
>>
>>> isDefined=function(x){try{return eval(x)}catch(e){return!1}}
>>> isDefined(a.b.c.d.e.f)
>>
>> It doesn't return a boolean but throws an error. Also I wonder if there is a way to avoid using eval for this type of thing. Seems like it could be a security risk to fire up eval() just to see if something exists.
>>
>> I will fiddle with it a bit to see if there might be another route.
>>
>> Thanks,
>>
>> Terry
>>
>>
>> On Nov 21, 2011, at 2:17 PM, Troy III Ajnej wrote:
>>
>>>
>>>
>>>
>>> isDefined
>>> ---------------------------8<------------------------------------------
>>> /* b.b. Troy III p.a.e. */
>>> isDefined=function(x){try{return eval(x)}catch(e){return!1}}
>>> --------------------------->8------------------------------------------
>>>
>>> readFrom
>>> -------------------------8<--------------------------------------------
>>> /* b.b. Troy III p.a.e. */
>>> readFrom=function(x,y){return isDefined(x)||y}
>>> ------------------------->8--------------------------------------------
>>>
>>> usage
>>> -------------------------8<--------------------------------------------
>>> title=readFrom("a.b.c.d.e.f.g.h.i.j.k.title", "untitled");alert(title);
>>>
>>> [element].innerText=readFrom("a.b.c.d.e.f.g.h.i.j.k.title", "untitled");
>>> -------------------------->8-------------------------------------------
>>>
>>> p.s.:
>>> sorry about the mess, I'm posting from Chrome[!?!]. Let's see...
>>>
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> Troy III
>>> progressive art enterprise
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Javascript mailing list
>>> Javascript at lists.evolt.org
>>> http://lists.evolt.org/mailman/listinfo/javascript
>>
>> Terry Riegel
>>
>> Put Your TimeClock on the Web
>> http://www.punchedin.com
>>
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>
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