A question on redirect_to

rubyonrails-talk
1

Hello,

I have been trying to do something like this.. I have an object which is being sent through to the view from the controller and since the object is not guarenteed to have non nil values, i use an exception handler to catch the exception upto which this works fine. However in the handler, I need to redirect to say an error page, it says "undefined method redirect_to".

The snippet from my view :

<%begin %> ... ....<some code that might give exception> ...

<% end %> <%rescue => msg %> <% logger.info "Exception occurred - " + msg.to_s %> <%= redirect_to :controller => 'my_controller', :action => 'error' %> <%end %>

This view is rendered thorough another action from the same controller 'my_controller'. When an exception occurs, it is caught and the point upto which the exception is rendered correctly. However, I would want the page to be redirected rather than being partially rendered. Is there anything that I am doing incorrectly here ? Any suggestions on this would be really helpful.

~Titan.

2

Seems to me as if you're having much too much logic in that view. Such decisions should be made in the controller The view should only display results.

3

This view is rendered thorough another action from the same controller 'my_controller'. When an exception occurs, it is caught and the point upto which the exception is rendered correctly. However, I would want the page to be redirected rather than being partially rendered. Is there anything that I am doing incorrectly here ? Any suggestions on this would be really helpful.

you can't redirect from the view. You might be able to use a rescue_from handler in your controller, although I think the approach you're taking is a bit fugly.

Fred

4

The issue you are having here is that you are trying to save yourself specific checks by using a global begin rescue block.

so if you dont have guranteed values. (I.e: columns which are not checked for presence) and want to display them in the view

then you should do something like:

<%= @model.columnname.uppercase if @model.columname %>

to avoid the error. "Undefined method uppercase for nil object"

yes, every time.

ps: you have your begin rescue bblock wrong.

begin    code_that_might_raise rescue Exception => e    more_code end

AND NOT

begin    code_that_might_raise end <-------------- this is wrong. rescue Exception => e    more_code end

Hope it heps

5

Does a rescue_from in the controller rescue exceptions in the view? I had problems with this a while back and just assumed it didn’t.

RSL

6

Thanks for all your quick thoughts on this. What Wolas had predicted is exactly the case that I am facing(a large set of legacy data); for which I wanted to have a global rescue blocks. But I had earlier faced some problems with rescue_from while dealing with the views and so I guess I would have to have individual validations for the fields before rendering them.

thanks! ~Titan.

7

Does a rescue_from in the controller rescue exceptions in the view?
I had problems with this a while back and just assumed it didn't.

can't remember, which is why I said might :-). It seems that any
exception thrown while rendering is wrapped inside an
ActionView::TemplateError and so that's the type you have to
rescue_from (which seems to work in a quick experiment)

Fred

8

aha! i’m sure that was it, i just wasn’t rescuing the right error.

RSL