Rails - May 2009 - instance variable (conroller>view) and RESTful

I''m a bit flummoxed by something and hoping someone can offer an
explanation.

If I create a controller (test) with a RESTfully named method and a
view (.../test/index), the value of the instance variable passes to
the view.

class TestController < ApplicationController
    def index
        @variable = ''Pass to a view''
    end
end
-------------

If I rename the view to (.../test/foo) or some other non-RESTful name
and appropriately alter the controller method, the value of the
instance variable does not pass.

class TestController < ApplicationController
    def foo
        @variable = ''Pass to a view''
    end
end
---------------

A half dozen inprint and online books seem to dispute my personla
experience and suggest that the name of the method and view should be
irrelevant.  So does anybody have a suggestion as to what is going
on?  Is my routes.rb file where I need to be looking?

Thanks much, Bill

As long as the name of the view and the method match it should work.
There is nothing special about the default methods in this respect.
Post a bit more code that exhibits the problem.  Presumably the view
is called views/test/foo.html.erb.  Unless there is something special
about a controller called ''test'' that is.

Colin

2009/5/31 zambezi
<b.butler-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>:
>
> I''m a bit flummoxed by something and hoping someone can offer an
> explanation.
>
> If I create a controller (test) with a RESTfully named method and a
> view (.../test/index), the value of the instance variable passes to
> the view.
>
> class TestController < ApplicationController
>    def index
>        @variable = ''Pass to a view''
>    end
> end
> -------------
>
> If I rename the view to (.../test/foo) or some other non-RESTful name
> and appropriately alter the controller method, the value of the
> instance variable does not pass.
>
> class TestController < ApplicationController
>    def foo
>        @variable = ''Pass to a view''
>    end
> end
> ---------------
>
> A half dozen inprint and online books seem to dispute my personla
> experience and suggest that the name of the method and view should be
> irrelevant.  So does anybody have a suggestion as to what is going
> on?  Is my routes.rb file where I need to be looking?
>
> Thanks much, Bill
> >
>

Well, as Colin says, there is nothing about the name of a method or
view that would muck with an instance variable working, but there
could also be something weird about TestController (that it *may* be
reserved, but i doubt it)...

Are you getting an error/stack trace?

Your routes could be an issue but you''d be getting an obvious error
(assuming you''re in dev mode) saying something to the effect of
"No
route matches "/test/foo" with {:method=>:get}"

Try posting some of your code and seeing if you get some clearer
answers. :)

Cheers!

On May 31, 1:37 am, Colin Law
<clan...-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
wrote:
> As long as the name of the view and the method match it should work.
> There is nothing special about the default methods in this respect.
> Post a bit more code that exhibits the problem.  Presumably the view
> is called views/test/foo.html.erb.  Unless there is something special
> about a controller called ''test'' that is.
>
> Colin
>
> 2009/5/31 zambezi
<b.but...-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>:
>
>
>
> > I''m a bit flummoxed by something and hoping someone can offer
an
> > explanation.
>
> > If I create a controller (test) with a RESTfully named method and a
> > view (.../test/index), the value of the instance variable passes to
> > the view.
>
> > class TestController < ApplicationController
> >    def index
> >        @variable = ''Pass to a view''
> >    end
> > end
> > -------------
>
> > If I rename the view to (.../test/foo) or some other non-RESTful name
> > and appropriately alter the controller method, the value of the
> > instance variable does not pass.
>
> > class TestController < ApplicationController
> >    def foo
> >        @variable = ''Pass to a view''
> >    end
> > end
> > ---------------
>
> > A half dozen inprint and online books seem to dispute my personla
> > experience and suggest that the name of the method and view should be
> > irrelevant.  So does anybody have a suggestion as to what is going
> > on?  Is my routes.rb file where I need to be looking?
>
> > Thanks much, Bill

Hi to Colin, Jennifer and anyone else,

If nothing else, this forum serves as a sanity check.

My difficulty arose when I created an application wide template as a
container for various views and attempted to pass a title variable to
the template.  None of my fiddling raised any errors.  After reading
your replies I went back to my application and sacrificed another hour
to Ruby idiosyncracies.  Here is what I''ve done and the results.

#-------- within layout/application
class LinkController < ApplicationController
    def display
        @title = "title (display)"
    end
    def index
      @title = "title (index)"
    end
    def foo
      @title = "title (foo)"
    end
end
----
    <title><%= @title %></title>
---
I created a view named ''display''  with the above embedded Ruby
and
opened it in the browser.  The title was BLANK.
Next I renamed the view ''index'' and opened it in the browser.
The
title appropriately showed "title (index)"
Then I renamed the view ''foo'' and again a BLANK title.
I renamed the view back to ''index'' and the title reappeared.

The above was with a template, so I decided to try the same fun
experiment with a standalone view.  And things got murkier.  Views
named ''index'' and ''foo'' display their
titles.  Views named ''display''
are BLANK.

Just on the off chance that Ruby is weirder than I think, I checked
the list of reserved words.  No conflicts there.  I also considered
there might be something bizarre about the title tags, so just stuck a
variable in the middle of the view <body> <@= @title
%></body>.  This
just reproduced the earlier results.

So there is the sad story.  Help!  I suppose I can just test all of my
view names to see if they pass muster, but I am really hoping to
eventually get to where Ruby is a time saver.

Any suggestions and/or comments on the instance variable behavior will
be welcomed.

Bill

2009/6/1 zambezi
<b.butler-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>:
>
>
> Hi to Colin, Jennifer and anyone else,
>
> If nothing else, this forum serves as a sanity check.
>
> My difficulty arose when I created an application wide template as a
> container for various views and attempted to pass a title variable to
> the template.  None of my fiddling raised any errors.  After reading
> your replies I went back to my application and sacrificed another hour
> to Ruby idiosyncracies.  Here is what I''ve done and the results.
>
> #-------- within layout/application
> class LinkController < ApplicationController
>    def display
>        @title = "title (display)"
>    end
>    def index
>      @title = "title (index)"
>    end
>    def foo
>      @title = "title (foo)"
>    end
> end
> ----
>    <title><%= @title %></title>
> ---
> I created a view named ''display''  with the above embedded
Ruby and
> opened it in the browser.  The title was BLANK.
> Next I renamed the view ''index'' and opened it in the
browser. The
> title appropriately showed "title (index)"
> Then I renamed the view ''foo'' and again a BLANK title.
> I renamed the view back to ''index'' and the title
reappeared.
>
> The above was with a template, so I decided to try the same fun
> experiment with a standalone view.  And things got murkier.  Views
> named ''index'' and ''foo'' display their
titles.  Views named ''display''
> are BLANK.
>
> Just on the off chance that Ruby is weirder than I think, I checked
> the list of reserved words.  No conflicts there.  I also considered
> there might be something bizarre about the title tags, so just stuck a
> variable in the middle of the view <body> <@= @title
%></body>.  This
> just reproduced the earlier results.
I presume you meant <%= rather than <@Did you include some fixed
identifiable text in each view to check
that the correct view is being shown?
The possible name conflicts are not so much with Ruby (which would
generally give an error of some sort) but with Rails.  Have you tried
other variable names?  This is certainly not a general problem or we
would all be falling over it all the time.
Have you checked in the log file (/log/development.log) for any errors?
>
> So there is the sad story.  Help!  I suppose I can just test all of my
> view names to see if they pass muster, but I am really hoping to
> eventually get to where Ruby is a time saver.
>
> Any suggestions and/or comments on the instance variable behavior will
> be welcomed.
>
> Bill
> >
>

Hello Colin,

I did mean <% instead of <@ and I did have some identifiable text with
each view name version.  Just cut out what I thought was extraneous to
the post.   I looked at the development.log and it is clean.  The only
differences between the view name versions were the expected time/
session/performance/etc.

The thought occurred to me that perhaps the use of duplicate view
names was the unlikely problem.  I''ve used ''display''
as a view name
several times across different folders.  But I renamed everything and
eliminated this as an issue.

So for now I am left with a Ruby on Rails app that just has a quirky
bias against ''display'' as a view name.  There are plenty of
alternative naming options and alternatives seem to work. So
ultimately not a big deal, though I''ll be carrying a niggling
suspicion that something will pop up and bite me one day.

Thank you much for the replies and support.  As I indicated earlier,
this forum serves as a sanity safety net that keeps me from doing
regrettable things to my computer.  If I ever turn up an explanation
for the problem I will pass it on.

Cheers, Bill

On Jun 2, 4:24 am, Colin Law
<clan...-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
wrote:
> 2009/6/1 zambezi
<b.but...-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>:
>
>
>
>
>
> > Hi to Colin, Jennifer and anyone else,
>
> > If nothing else, this forum serves as a sanity check.
>
> > My difficulty arose when I created an application wide template as a
> > container for various views and attempted to pass a title variable to
> > the template.  None of my fiddling raised any errors.  After reading
> > your replies I went back to my application and sacrificed another hour
> > to Ruby idiosyncracies.  Here is what I''ve done and the
results.
>
> > #-------- within layout/application
> > class LinkController < ApplicationController
> >    def display
> >        @title = "title (display)"
> >    end
> >    def index
> >      @title = "title (index)"
> >    end
> >    def foo
> >      @title = "title (foo)"
> >    end
> > end
> > ----
> >    <title><%= @title %></title>
> > ---
> > I created a view named ''display''  with the above
embedded Ruby and
> > opened it in the browser.  The title was BLANK.
> > Next I renamed the view ''index'' and opened it in the
browser. The
> > title appropriately showed "title (index)"
> > Then I renamed the view ''foo'' and again a BLANK
title.
> > I renamed the view back to ''index'' and the title
reappeared.
>
> > The above was with a template, so I decided to try the same fun
> > experiment with a standalone view.  And things got murkier.  Views
> > named ''index'' and ''foo'' display
their titles.  Views named ''display''
> > are BLANK.
>
> > Just on the off chance that Ruby is weirder than I think, I checked
> > the list of reserved words.  No conflicts there.  I also considered
> > there might be something bizarre about the title tags, so just stuck a
> > variable in the middle of the view <body> <@= @title
%></body>.  This
> > just reproduced the earlier results.
>
> I presume you meant <%= rather than <@> Did you include some fixed
identifiable text in each view to check
> that the correct view is being shown?
> The possible name conflicts are not so much with Ruby (which would
> generally give an error of some sort) but with Rails.  Have you tried
> other variable names?  This is certainly not a general problem or we
> would all be falling over it all the time.
> Have you checked in the log file (/log/development.log) for any errors?
>
>
>
> > So there is the sad story.  Help!  I suppose I can just test all of my
> > view names to see if they pass muster, but I am really hoping to
> > eventually get to where Ruby is a time saver.
>
> > Any suggestions and/or comments on the instance variable behavior will
> > be welcomed.
>
> > Bill

On Jun 2, 4:28 pm, zambezi
<b.but...-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>
wrote:
> Hello Colin,
>
> I did mean <% instead of <@ and I did have some identifiable text
with
> each view name version.  Just cut out what I thought was extraneous to
> the post.   I looked at the development.log and it is clean.  The only
> differences between the view name versions were the expected time/
> session/performance/etc.
>
> The thought occurred to me that perhaps the use of duplicate view
> names was the unlikely problem.  I''ve used
''display'' as a view name
> several times across different folders.  But I renamed everything and
> eliminated this as an issue.
>
> So for now I am left with a Ruby on Rails app that just has a quirky
> bias against ''display'' as a view name.  There are plenty
of
> alternative naming options and alternatives seem to work. So
> ultimately not a big deal, though I''ll be carrying a niggling
> suspicion that something will pop up and bite me one day.
>
Have you checked whether your action ever gets called (stick a
breakpoint in there). ?

Fred
> Thank you much for the replies and support.  As I indicated earlier,
> this forum serves as a sanity safety net that keeps me from doing
> regrettable things to my computer.  If I ever turn up an explanation
> for the problem I will pass it on.
>
> Cheers, Bill
>
> On Jun 2, 4:24 am, Colin Law
<clan...-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>
> > 2009/6/1 zambezi
<b.but...-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>:
>
> > > Hi to Colin, Jennifer and anyone else,
>
> > > If nothing else, this forum serves as a sanity check.
>
> > > My difficulty arose when I created an application wide template
as a
> > > container for various views and attempted to pass a title
variable to
> > > the template.  None of my fiddling raised any errors.  After
reading
> > > your replies I went back to my application and sacrificed another
hour
> > > to Ruby idiosyncracies.  Here is what I''ve done and the
results.
>
> > > #-------- within layout/application
> > > class LinkController < ApplicationController
> > >    def display
> > >        @title = "title (display)"
> > >    end
> > >    def index
> > >      @title = "title (index)"
> > >    end
> > >    def foo
> > >      @title = "title (foo)"
> > >    end
> > > end
> > > ----
> > >    <title><%= @title %></title>
> > > ---
> > > I created a view named ''display''  with the
above embedded Ruby and
> > > opened it in the browser.  The title was BLANK.
> > > Next I renamed the view ''index'' and opened it
in the browser. The
> > > title appropriately showed "title (index)"
> > > Then I renamed the view ''foo'' and again a BLANK
title.
> > > I renamed the view back to ''index'' and the
title reappeared.
>
> > > The above was with a template, so I decided to try the same fun
> > > experiment with a standalone view.  And things got murkier.
 Views
> > > named ''index'' and ''foo''
display their titles.  Views named ''display''
> > > are BLANK.
>
> > > Just on the off chance that Ruby is weirder than I think, I
checked
> > > the list of reserved words.  No conflicts there.  I also
considered
> > > there might be something bizarre about the title tags, so just
stuck a
> > > variable in the middle of the view <body> <@= @title
%></body>.  This
> > > just reproduced the earlier results.
>
> > I presume you meant <%= rather than <@> > Did you include
some fixed identifiable text in each view to check
> > that the correct view is being shown?
> > The possible name conflicts are not so much with Ruby (which would
> > generally give an error of some sort) but with Rails.  Have you tried
> > other variable names?  This is certainly not a general problem or we
> > would all be falling over it all the time.
> > Have you checked in the log file (/log/development.log) for any
errors?
>
> > > So there is the sad story.  Help!  I suppose I can just test all
of my
> > > view names to see if they pass muster, but I am really hoping to
> > > eventually get to where Ruby is a time saver.
>
> > > Any suggestions and/or comments on the instance variable behavior
will
> > > be welcomed.
>
> > > Bill

Hi Frederick,

I can''t give you a direct answer since the breakpoints in my IDE
don''t
work.  Actually I can set them in .rb files, but no response under any
conditions.  So at the moment I can only verify that the method is
being called.   I''m not sure if I can set a command line breakpoint.


Cheers,
Bill

On Jun 3, 4:33 am, zambezi
<b.but...-GrTI0ftTvuWGJGYlWa3Ukdi2O/JbrIOy@public.gmane.org>
wrote:
> Hi Frederick,
>
> I can''t give you a direct answer since the breakpoints in my IDE
don''t
> work.  Actually I can set them in .rb files, but no response under any
> conditions.  So at the moment I can only verify that the method is
> being called.   I''m not sure if I can set a command line
breakpoint.
>
you can always resort to slightly more primitive methods, eg stick

raise "I''ve been run"

in the action method.

Fred
> Cheers,
> Bill

Hello again Frederick,

I took up your suggestion and it was revelatory, though I''m not sure
what it reveals.

With a view and action named ''display'', an exception was NOT
raised
from the action.  With alternative names, the exception was raised as
expected.

I created another application and got the same results.  I''m curious
as to whether this behavior is repeatable on someone else''s setup.

Cheers, Bill