Update array in rails action?

Question

Hey guys,

I have the following code in an action:

@user = @current_user
@user.votes[1430]='up'
@user.update_attributes(params[:user])

Votes is a string type, there is no default value - I just want to set it for the first time when this action occurs.

Unfortunately I get this error: NoMethodError

You have a nil object when you didn't expect it! The error occurred while evaluating nil.votes

any ideas what I'm doing wrong?

Answer 1

The cause of the error seems to be that @user is a nil reference.

You can confirm this by using logging and checking in your console window:

logger.info "user is nil" if @user.nil?

You are assigning @user to be the value of @current_user. I've seen this pattern before and usually current_user is a function, declared elsewhere, not an instance variable. If you are using that pattern, the line should be something like @user = current_user instead.

(Additionally, if votes is a string, your second line appears to be referring to index 1430 of that string, which is probably not what you want either.)

Answer 2

I'm splitting off the comments as I don't want to hijack Evil Trouts response and we seem to be veering away from what was initially spoken about.

Unfortunately I get this error: NoMethodError

You have a nil object when you didn't expect it! The error occurred while evaluating nil.votes

For this, have a look at the authlogic example application. My guess is that you don't have the appropriate before_filter set up and aren't requiring the user to be logged in on that action.

the 1430 is actually two seperate IDs

I don't fully follow this. It's a concatenation of two IDs? What are the IDs for? To be honest, I've never used an array as being a field type in my database so I don't know what the advantages of it are, but whenever I think to myself that an array would be a good idea, I usually question whether or not it wouldn't be better to just have it be a separate model, and hence, table.

It sounds like the situation you are describing might have a Question which a User can vote up on. If so, I might have a separate Voteable model which would join the users with the questions they can vote 'up' on.

Maybe if you provide some more insight into this side of things, I can make a better suggestion. Cheers.