Forum: Ruby on Rails Comment has_many comments

Hi,

I want to create web application where people can discuss some things.
There will be a Posts and users can comment it, but I also want users 
can
comment commentaries.
Can I create model comment, that belongs_to comment and has_many 
comments,
or smth similar?

I only studying Rails. Sorry for my bad english.

On 17 January 2013 18:32, Роман Пружанский <19prv94@gmail.com> wrote:
> Hi,
>
> I want to create web application where people can discuss some things.
> There will be a Posts and users can comment it, but I also want users can
> comment commentaries.
> Can I create model comment, that belongs_to comment and has_many comments,
> or smth similar?

Start by working through the tutorial at railstutorial.org.  That will
give you a good understanding of the basics of rails.  Also look at
the Rails Guides.  When working through any tutorial make sure that
the tutorial is for rails 3 and that you have installed exactly the
rails version that the tutorial expects.

Colin

On Jan 17, 2013, at 1:32 PM, Роман Пружанский wrote:

> Hi,
>
> I want to create web application where people can discuss some things.
> There will be a Posts and users can comment it, but I also want users can 
comment commentaries.
> Can I create model comment, that belongs_to comment and has_many comments, or 
smth similar?
>
> I only studying Rails. Sorry for my bad english.

You may want to look at Single Table Inheritance for this. That's a 
pretty simple way to make a linked list, which is what you're 
describing.

Walter

On 17 January 2013 21:51, Walter Lee Davis <waltd@wdstudio.com> wrote:
>
> You may want to look at Single Table Inheritance for this. That's a pretty 
simple way to make a linked list, which is what you're describing.

Walter, can you give a link or a brief description on how to use STI
to implement a linked list, or a link to a description?  I have not
come across that idea before.

thanks

Colin

On Jan 17, 2013, at 5:01 PM, Colin Law wrote:

>>> I only studying Rails. Sorry for my bad english.
>>
>> You may want to look at Single Table Inheritance for this. That's a pretty 
simple way to make a linked list, which is what you're describing.
>
> Walter, can you give a link or a brief description on how to use STI
> to implement a linked list, or a link to a description?  I have not
> come across that idea before.

I am pretty sure I am mis-remembering the name of the thing. The more I 
look at it, the more wrong  I think I am here.

Sorry for the noise. I'll try to remember what I was thinking of here...

Walter

On Jan 17, 2013, at 5:31 PM, Walter Lee Davis wrote:

>>>> There will be a Posts and users can comment it, but I also want users can 
comment commentaries.
> I am pretty sure I am mis-remembering the name of the thing. The more I look at 
it, the more wrong  I think I am here.
>
> Sorry for the noise. I'll try to remember what I was thinking of here...

Maybe this: https://github.com/stefankroes/ancestry

Not a linked list, but something called a "materialized path".

I figured out why I was thinking STI -- I made a forum years ago that 
had Threads and Comments, organized in an STI table. There was only one 
layer of inheritance, not what the OP was asking for. If you were only 
ever looking at a chronological list of comments, you could have a 
:parent attribute that was a self-reference to another record in the 
same table. That could give you your nesting structure, simply by 
looking up the chain of ancestors to the root.

Walter

On 17 January 2013 18:32, Роман Пружанский <19prv94@gmail.com> wrote:
> Hi,
>
> I want to create web application where people can discuss some things.
> There will be a Posts and users can comment it, but I also want users can
> comment commentaries.
> Can I create model comment, that belongs_to comment and has_many comments,
> or smth similar?

I think what you are looking for is a self referential model.  If you 
google for
rails self referential
you will find suggestions on how to do it.  Start with some of the
later links however as the details of rails has changed over the
years.  The basic principle is still the same though.  My earlier
suggestion of working through tutorials to get the basics still stands
however, if you have not already done that.

Colin