General architechture / MVC question

Hi all,

A newbie with Ruby on Rails - and programming in general - I’m working
on a few Flash and PHP projects as well. Partly to make my work more
efficient, partly to gain a better understanding of system architecture
/ design patterns, I’ve been trying to use the MVC pattern in
database-backed Flash / Actionscript development as well.

I think / hope that I’m beginning to grasp the concept of patterns - and
of the MVC one.

One question however; if starting out designing a new MVC application,
how do I identify the Model classes - will it always be one model per DB
table? And is there a general ‘model’ for identifying controllers - when
you start out from scratch developing a new app?

Any feedback much appreciated,
BR Bo / Rails newbie

I’m also new to this stuff, but as far as I’ve seen, you have one model
class for each table in the DB. More especifically, you have one
ActiveRecord::Base class for each table. If you have another model but
is not related to any table (dunno, a transient class), you will have
another file in your app/model, but just defined as “class
TransientStuff end”, not ActiveRecord.

(I don’t understand the question about the “general model” :)).

Bo Vittrup wrote:

Hi all,

A newbie with Ruby on Rails - and programming in general - I’m working
on a few Flash and PHP projects as well. Partly to make my work more
efficient, partly to gain a better understanding of system architecture
/ design patterns, I’ve been trying to use the MVC pattern in
database-backed Flash / Actionscript development as well.

I think / hope that I’m beginning to grasp the concept of patterns - and
of the MVC one.

One question however; if starting out designing a new MVC application,
how do I identify the Model classes - will it always be one model per DB
table? And is there a general ‘model’ for identifying controllers - when
you start out from scratch developing a new app?

Any feedback much appreciated,
BR Bo / Rails newbie

On 11 Aug 2006, at 16:47, Bo Vittrup wrote:

A newbie with Ruby on Rails - and programming in general - I’m working
on a few Flash and PHP projects as well. Partly to make my work more
efficient, partly to gain a better understanding of system
architecture
/ design patterns, I’ve been trying to use the MVC pattern in
database-backed Flash / Actionscript development as well.

I think / hope that I’m beginning to grasp the concept of patterns

  • and
    of the MVC one.

Skipping carefully over the idea that MVC might be a lowly pattern…

One question however; if starting out designing a new MVC application,
how do I identify the Model classes - will it always be one model
per DB
table?

If you are starting out, a model class will usually be one per table,
yes. But be aware that you are likely to be able to identify models
that don’t map to any table at all, and may have designs that require
more than one model class per table. And some tables (join tables,
mostly) won’t require classes.

And is there a general ‘model’ for identifying controllers - when
you start out from scratch developing a new app?

Controllers can be viewed as convenient groupings of actions,
possibly optimised by how they share supporting methods and helpers.
I like the idea that actions in one controller share a layout - so
the number of controllers in your app is the same as the number of
layouts. That is all very crude, and is really a matter of taste
more than anything else.

Paul

Thank you both for your comments. I think that I understand better now
that there is no ‘one way’ of structuring an application using a
particular pattern model, and that in the end a lot depends on personal
preferences and tastes.

However, your answers together with various tutorials using different
programming languages (Java, Actionscript etc.) forms a good starting
point - and from there the only way is probably to try it out a thousand
times for oneself and adjust and get smarter along the way : ) And -
anyway, as long as you stick to Rails, it is great that a lot of the
thinking has already been done and that you’re able to build on lots of
experience gained by others.

Br Bo

Paul L. wrote:

On 11 Aug 2006, at 16:47, Bo Vittrup wrote:

A newbie with Ruby on Rails - and programming in general - I’m working
on a few Flash and PHP projects as well. Partly to make my work more
efficient, partly to gain a better understanding of system
architecture
/ design patterns, I’ve been trying to use the MVC pattern in
database-backed Flash / Actionscript development as well.

I think / hope that I’m beginning to grasp the concept of patterns

  • and
    of the MVC one.

Skipping carefully over the idea that MVC might be a lowly pattern…

One question however; if starting out designing a new MVC application,
how do I identify the Model classes - will it always be one model
per DB
table?

If you are starting out, a model class will usually be one per table,
yes. But be aware that you are likely to be able to identify models
that don’t map to any table at all, and may have designs that require
more than one model class per table. And some tables (join tables,
mostly) won’t require classes.

And is there a general ‘model’ for identifying controllers - when
you start out from scratch developing a new app?

Controllers can be viewed as convenient groupings of actions,
possibly optimised by how they share supporting methods and helpers.
I like the idea that actions in one controller share a layout - so
the number of controllers in your app is the same as the number of
layouts. That is all very crude, and is really a matter of taste
more than anything else.

Paul

This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.

| Privacy Policy | Terms of Service | Remote Ruby Jobs