# RJS & ReferenceError

**URL:** <https://www.ruby-forum.com/t/rjs-referenceerror/69360>\
**Category:** Rails\
**Created:** [September 20, 2006, 3:54pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360 "2006-09-20T15:54:50Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Aleksander\_PejSSSSi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/0ea827/32.png) [@Aleksander\_PejSSSSi](https://www.ruby-forum.com/u/Aleksander_PejSSSSi)\
**Post date:** [September 20, 2006, 3:54pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360/1 "2006-09-20T15:54:50Z")

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Hello,

is there a way to suppress rjs error messages, because i am trying to  
check  
if some variable is present, with (variable == undefined), but rjs stops  
processing and throws out error, because there is \>\>reference error\<\<.  
Whatever, this is javascript, you cannot have reference error in  
javascript…

BTW: i know i could just create a javascript file, and assign undefined  
values to variables, but that would kinda suck.

Thanks for any suggestions.

---

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**Author:** ![Aleksander\_PejSSSSi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/0ea827/32.png) [@Aleksander\_PejSSSSi](https://www.ruby-forum.com/u/Aleksander_PejSSSSi)\
**Post date:** [September 20, 2006, 6:24pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360/2 "2006-09-20T18:24:01Z")

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Aleksander PejčiÄ? wrote:

> Hello,
> 
> is there a way to suppress rjs error messages, because i am trying to  
> check  
> if some variable is present, with (variable == undefined), but rjs stops  
> processing and throws out error, because there is \>\>reference error\<\<.  
> Whatever, this is javascript, you cannot have reference error in  
> javascript…

This isn’t rjs stopping processing, it’s your browser throwing the  
exception while evaluating the javascript (which just happens to be  
created via rjs).  
see [Q778 How can I test to see if a variable has been assigned a value/declared?](http://www.irt.org/script/778.htm) for testing for the presence of a  
variable.

Fred

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**Author:** ![Aleksander\_PejSSSSi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/0ea827/32.png) [@Aleksander\_PejSSSSi](https://www.ruby-forum.com/u/Aleksander_PejSSSSi)\
**Post date:** [September 20, 2006, 7:27pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360/3 "2006-09-20T19:27:20Z")

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You must be mistaken…

i have this code:  
if(timer == undefined)  
timer = setTimeout(“effect = new fx.Opacity($(‘login\_message’),  
{duration: 2000, onComplete: function() { timer =  
undefined;}}).toggle();”, 2000);

You can probably see what i am trying to accomplish.

And it work if i use it like a regular javascript, which means putting  
it in external .js file or “inlineing” it html file, but when i use  
this inside rjs file with page \<\< “…” directive, i get rjs warnig  
about reference error.

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<div class="post-metadata">

**Author:** ![Aleksander\_PejSSSSi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/0ea827/32.png) [@Aleksander\_PejSSSSi](https://www.ruby-forum.com/u/Aleksander_PejSSSSi)\
**Post date:** [September 20, 2006, 7:43pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360/4 "2006-09-20T19:43:23Z")

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some more fun:

page \<\< " alert(typeof timer); ", messaged that timer is undefined, and  
right after i pressed ok, a new alert popped up whining about rjs  
reference error

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<div class="post-metadata">

**Author:** ![Aleksander\_PejSSSSi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/0ea827/32.png) [@Aleksander\_PejSSSSi](https://www.ruby-forum.com/u/Aleksander_PejSSSSi)\
**Post date:** [September 20, 2006, 7:55pm UTC](https://www.ruby-forum.com/t/rjs-referenceerror/69360/5 "2006-09-20T19:55:23Z")

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Update: (typeof timer == ‘undefined’) worked