Ruby on Rails

On 19 February 2015 at 13:57, TTambe <tambe257@gmail.com> wrote:
> Someone suggested that I use local variables like this:
>
> <% @pin_albums.each do |pin| %>
>   <%= (last_artist ||= nil) != pin.artist ? (last_artist = pin.artist) : ''
> %> |
>   <%= link_to pin.album, copy_pin_path(pin) %>
>   <br/>
> <% end %>
>
> This gives me the same result as my original code:
>
> The Beatles | Let It Be
> The Beatles | Abbey Road
> Bob Dylan | Blood On The Tracks
> Bob Dylan | Highway 61 Revisited

That looks as if it should work.  Have you posted a direct copy/paste
from your code?
It assigns nil to last_artist unless last_artist already has a value,
then compares that to pin.artist.  If not the same (so a new artist)
it assigns pin.artist to last_artist and displays that, if the the
same then it displays an empty string.
I wonder whether the precedence is wrong. If the above is a copy/paste
from your code then try
((last_artist ||= nil) != pin.artist) ? (last_artist = pin.artist) : ''
Note the extra parentheses

If that still doesn't work add a column on the end of the line showing
last_artist and see if it is tracking correctly.

Colin

>
> I'm not well versed on writing local variables in RoR, so I'm not sure that
> I'm analyzing this correctly, but I don't see where last_artist is
> referencing the last iteration of the loop. I was thinking of trying to use
> @pin_albums.each.with_index and then somehow comparing pin.artist to
> pin.artist - 1
>
> Any thoughts from everyone would be appreciated.
> Thanks!
>
> On Tue, Feb 17, 2015 at 11:07 AM, Colin Law <clanlaw@gmail.com> wrote:
>>
>> On 17 February 2015 at 15:39, Tony Tambe <tambe257@gmail.com> wrote:
>> > In my music review app the Pins model has attributes of Pin.artist and
>> > Pin.album. I'm trying to list each artist reviewed on the site and which
>> > albums of theirs have been reviewed. Below is what I have so far, but I
>> > want
>> > to do it without repeating the artist name.
>> >
>> > Controller:
>> >
>> > @pin_albums = Pin.group(:album).order('artist')
>> >
>> > View:
>> >
>> > <% @pin_albums.each do |pin| %>
>> >   <%= pin.artist %> |
>> >   <%= link_to pin.album, copy_pin_path(pin) %>
>> >   <br/>
>> > <% end %>
>> >
>> > This lists them like this:
>> >
>> > The Beatles | Let It Be The Beatles | Abbey Road Bob Dylan | Blood On
>> > The
>> > Tracks Bob Dylan | Highway 61 Revisited
>> >
>> > I want to list them like so:
>> >
>> > The Beatles | Let It Be
>> >             | Abbey Road
>> > Bob Dylan | Blood On The Tracks
>> >           | Highway 61 Revisited
>>
>> Leave the artist cell blank if the artist this time is the same as the
>> artist last time.
>>
>> Colin
>>
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