Strange thing in Rails views

rubyonrails-talk
1

Hello people,

I am developing an app with Rails 4.0.x and I have a strange bug in its view. Say I have a partial like this

%p= @bject,name # would work perfectly

= render @object.friends # It won’t fetch this relation

%p= @object,name # It would say can’t find name for nil class

For some reason the above stuff happens. However in the rails console, all would work fine. Kinda confused.

Would be great if any one could throw light on this. Don’ know if this is a Rails bug where state of instance variable gets forgotten after some time.

2

Hello people,

I am developing an app with Rails 4.0.x and I have a strange bug in its view. Say I have a partial like this

%p= @bject,name # would work perfectly

Does using @object,name also work (not @bject which you have written above)?

= render @object.friends # It won't fetch this relation

What do you mean it will not fetch the relation? What is the error message?

%p= @object,name # It would say can't find name for nil class

Then @object is nil. Perhaps you should be using @bject.

Note that when posting code it is better to copy/paste then there will be no confusion about what the code actually is.

For some reason the above stuff happens. However in the rails console, all would work fine. Kinda confused.

Would be great if any one could throw light on this. Don' know if this is a Rails bug where state of instance variable gets forgotten after some time.

My experience is that bugs in compilers/frameworks/OSs are very rarely the cause of problems. 99.999% it is one's own code that is at fault.

Colin

3

> Hello people, > > I am developing an app with Rails 4.0.x and I have a strange bug in its > view. Say I have a partial like this > > %p= @bject,name # would work perfectly

Does using @object,name also work (not @bject which you have written above)?

Actually the variable name is not @Object. Its some thing else. Have checked spelling, copied and pasted it. But nope. It won't work.

> > = render @object.friends # It won't fetch this relation

What do you mean it will not fetch the relation? What is the error message?

There shows no error, it just returns nil object. If I give @ obj.friends.first.name , it would say undefined method first for nil object!

> > %p= @object,name # It would say can't find name for nil class

Then @object is nil. Perhaps you should be using @bject.

Note that when posting code it is better to copy/paste then there will be no confusion about what the code actually is.

Yup copied, pasted and banged my head on desk a 1000 times.

Say if in the action if I keep @object2 = Person.find params[:id] and if I use @object2 in code, it works perfectly everywhere. This bug is repeatable on server and my local system running ruby 2.1.0 and Rails 4.3.

Some how rails is forgetting what @object is in the middle of view.

For some reason the above stuff happens. However in the rails console, all would work fine. Kinda confused.

Would be great if any one could throw light on this. Don' know if this is

a

Rails bug where state of instance variable gets forgotten after some time.

My experience is that bugs in compilers/frameworks/OSs are very rarely

4

> Hello people, > > I am developing an app with Rails 4.0.x and I have a strange bug in its > view. Say I have a partial like this > > %p= @bject,name # would work perfectly

Does using @object,name also work (not @bject which you have written above)?

Actually the variable name is not @Object. Its some thing else. Have checked spelling, copied and pasted it. But nope. It won't work.

> > = render @object.friends # It won't fetch this relation

What do you mean it will not fetch the relation? What is the error message?

There shows no error, it just returns nil object. If I give @obj.friends.first.name , it would say undefined method first for nil object!

> > %p= @object,name # It would say can't find name for nil class

Then @object is nil. Perhaps you should be using @bject.

Note that when posting code it is better to copy/paste then there will be no confusion about what the code actually is.

Yup copied, pasted and banged my head on desk a 1000 times.

I meant that you should copy/paste the code here rather than typing something similar for us to look at.

Say if in the action if I keep @object2 = Person.find params[:id] and if I use @object2 in code, it works perfectly everywhere. This bug is repeatable on server and my local system running ruby 2.1.0 and Rails 4.3.

Some how rails is forgetting what @object is in the middle of view.

I don't think it is at all likely that it is forgetting it, but if you don't show us the actual failing code then it is difficult to help. You could try inserting puts statements in the code (which will appear in the server log) between the point at which it knows the variable and the point at which you think it has forgotten, in order to see which bit of code is causing it to be 'forgotten'.

As I said it is most likely something in your code that is causing the problem, but if you do not show us the actual code (just the failing area) then it is difficult to help.

Colin

5

I’m going to assume the “3” in “4.3” is a typo - otherwise, say hi to the future people for me. :slight_smile:

Anyways, the usual cause of weird name-specific behavior is that you’ve picked a name which is used internally by part of Rails. Sanitizing your example to “@object” rather than the real name is going to make this difficult to troubleshoot…

–Matt Jones

6

Ya possibly. Any way did a work around. Thanks a lot for your replies.