How to use a variable in several controllers?
António
Dear all,
I am a new "Ruby/Ruby on Rails" programmer. I am not sure this is the correct forum for my question. If this is not the correct forum, please indicate me a more appropriate one.
When my application implements a URL, an array, @session, is used in several methods of a first controller. The application redirects to another page, making a second controller being invoked. This controller does not use the array. When the method of the second controller ends, a layout is implicitly rendered. The layout has the following code:
...
<body>
<% if @session.length == 0 then %>
...
I got the following error message when trying to implement the URL: undefined method `length' for nil:NilClass.
What should I do in order to the array be recognized by the second controller?
Regards,
António.
Colin Law
good tutorial such as railstutorial.org (which is free to use online).
That will show you the basics of rails.
As for your question are you trying to use the rails session variable?
If so then it is session, not @session. If it is a variable of your
own then you cannot directly pass it from one controller to another.
Each request to the webserver starts from a clean slate. Remember,
for example, the server could be shut down and restart between
requests. You must re-calculate your variable at each request. The
exception is the session variable that I mentioned which is passed,
normally, via cookies.
As I said work through a good tutorial before going any further.
Colin
Colin Law
> Hi Colin,
>
>
> Thanks for your answer,
>
>
>
> The variable @session is a variable I "created" to store the "user id" of a
> user when the user logs in.
>
>
>
> The second controller checks the variable for knowing whether a user is
> logged in. The idea is the @session variable to be a "global variable" of
> the application, that is, used by several controllers. According to your
> answer, it is not possible. Is that true?
Whilst technically it may be possible in some situations that is
certainly not the way to achieve the result you want. If it contains
data that can be recalculated then possibly use a before filter.
Alternatively the rails session variable may be the right way to go.
As I said, work right through a good tutorial and such things should
become clear, or at least less muddy.
Colin
