strange array behaviour

[Matt Harrison]

I've got a relationship:

Person has many MiddleNames
and
MiddleName belongs to Person

In irb I can add a person, add a middle name then call

@person.middle_names.first.name

to get that middle name. However when I try the exact same code in a view, I
get

undefined method `name' for nil:NilClass

If I iterate through like so:

for mname in @person.middle_names
puts mname.name

Then it works perfectly, but for some reason using ".first" is failing in
the view. I've used this method many many times and never come across
anything quite like this.

I believe I'm probably overlooking some incredibly simple answer and I'm
going to kick myself when someone points it out, but for now I'm completely
stumpted.

Any input appreciated.

Thanks

Matt

[Pale Horse]

> for mname in @person.middle_names
> puts mname.name
>
> Then it works perfectly, but for some reason using ".first" is failing
> in
> the view. I've used this method many many times and never come across
> anything quite like this.

".first" is an array method. "mname.name" is an instance of an array...

Hope this helps...

> I believe I'm probably overlooking some incredibly simple answer and I'm
> going to kick myself when someone points it out, but for now I'm

> completely stumped.
--
Posted via http://www.ruby-forum.com/.

[Matt Harrison]

On Sat, Dec 26, 2009 at 11:40:00PM +0100, Pale Horse wrote:
> > for mname in @person.middle_names
> > puts mname.name
> >
> > Then it works perfectly, but for some reason using ".first" is failing
> > in
> > the view. I've used this method many many times and never come across
> > anything quite like this.
>
> ".first" is an array method. "mname.name" is an instance of an array...
>
> Hope this helps...

Thanks, but I've just noticed something:

The error I am getting only appears from my testing with cucumber/rspec/webrat. If I
access the page manually through passenger, it all works perfectly.

I might contact the cuke list about this as the code is obviously correct, it works
fine in irb and in a real browser, just not in the test environment. So much for me
sticking to my BDD plans :D

Thanks

Matt

[Rick DeNatale]

On Sat, Dec 26, 2009 at 3:20 PM, Matt Harrison
<iwasinn...@genestate.com> wrote:
> I've got a relationship:
>
> Person has many MiddleNames
> and
> MiddleName belongs to Person
>
>
> In irb I can add a person, add a middle name then call
>
> @person.middle_names.first.name

And what happens if you don't add a middle name.

[].first #=> nil

>
> to get that middle name. However when I try the exact same code in a view, I
> get
>
> undefined method `name' for nil:NilClass
>
> If I iterate through like so:
>
> for mname in @person.middle_names
>  puts mname.name

Because if @person.middle_names is empty the loop body is not executed.

>
> Then it works perfectly, but for some reason using ".first" is failing in
> the view. I've used this method many many times and never come across
> anything quite like this.
>
> I believe I'm probably overlooking some incredibly simple answer and I'm
> going to kick myself when someone points it out, but for now I'm completely
> stumpted.
>
> Any input appreciated.
>
> Thanks
>
> Matt
>

--
Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Twitter: http://twitter.com/RickDeNatale
WWR: http://www.workingwithrails.com/person/9021-rick-denatale
LinkedIn: http://www.linkedin.com/in/rickdenatale

[Matt Harrison]

On Sat, Dec 26, 2009 at 09:43:26PM -0500, Rick DeNatale wrote:
> On Sat, Dec 26, 2009 at 3:20 PM, Matt Harrison
> <iwasinn...@genestate.com> wrote:
> > I've got a relationship:
> >
> > Person has many MiddleNames
> > and
> > MiddleName belongs to Person
> >
> >
> > In irb I can add a person, add a middle name then call
> >
> > @person.middle_names.first.name
>
> And what happens if you don't add a middle name.
>
> [].first #=> nil

That is true, but in my scenario I have added a middle name and related it to that
person. I will of course go and triple check that but I have executed the copy and
pasted commands from the cuke steps and it worked in irb.

Its quite possible I have slipped up but I will go and check. Thanks

>
> >
> > to get that middle name. However when I try the exact same code in a view, I
> > get
> >
> > undefined method `name' for nil:NilClass
> >
> > If I iterate through like so:
> >
> > for mname in @person.middle_names

> > ?puts mname.name

>
>
> Because if @person.middle_names is empty the loop body is not executed.

But it does execute the loop, and prints out the first of the names as expected. This
is the weird thing.

[Liu Lantao]

maybe 'puts @person.middle_names.inspect' will give some information of
the structure .

> --
>
> You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group.
> To post to this group, send email to rubyonra...@googlegroups.com.
> To unsubscribe from this group, send email to rubyonrails-ta...@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
>
>
>
>