# Sequencing control with edit method in CRUD examples

**URL:** <https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436>\
**Category:** Rails\
**Created:** [July 7, 2006, 2:29am UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436 "2006-07-07T02:29:32Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 2:29am UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/1 "2006-07-07T02:29:32Z")

</div>

I have been playing with the cookbook type of tutorials building a fish  
tournament scoring piece and am having a bit of a problem with a DB  
field called “points” in my “catch” table that is not input by the user  
but is calulated based on a “size” field that is input by the user.

I have the following in my catch\_controller.db

def new  
@catch = Catch.new  
@fish = Fish.find\_all  
@bait = Bait.find\_all  
end

def create  
@catch = Catch.new(@params[‘catch’])  
@catch.datetime = DateTime.now  
@catch.points = @catch.size  
if @catch.bait\_id == 2  
@catch.points = @catch.size + (@catch.size/10)  
end  
if @catch.bait\_id == 3  
@catch.points = @catch.size + (@catch.size/5)  
end  
if @catch.save  
redirect\_to :action =\> ‘list’  
else  
render\_action ‘new’  
end  
end

Granted it’s not particularly elegant but when a new catch is entered  
the “points” are correctly set in the create method. The problem I am  
having is in “Edit”.

def edit  
@catch = Catch.find(@params[“id”])  
@fish = Fish.find\_all  
@bait = Bait.find\_all

```
@catch.points = @catch.size
	if @catch.bait_id == 2
		@catch.points = @catch.size + (@catch.size/10)
	end
	if @catch.bait_id == 3
		@catch.points = @catch.size + (@catch.size/5)
	end
if @catch.save
    redirect_to :action => 'list'
else
    render_action 'new'
end

```

end

Where or in what method would I put similar code so that when someone  
edits the “size” field of a record the “points” are properly tabulated?  
The code above does not correctly work as it does for the new/create  
function. Should this code be in an update method? What runs after the  
edit view?

With default edit/update scaffolding I am seeing the “size” properly  
updated but no effect on “points”. But if I then go back into the record  
with the edit view and “submit” with no further changes the “points” are  
magically updated. WTF is going on and how do I get my code to set the  
points in the proper place? Clearly it does not belong in the edit view  
…

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 3:39am UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/2 "2006-07-07T03:39:58Z")

</div>

Nevermind, solved. But a real POS solution. Clearly I am missing  
something here.

def update  
@catch = Catch.find(params[:id])  
if @catch.update\_attributes(params[:catch])  
@catch.points = @catch.size  
if @catch.bait\_id == 2  
@catch.points = @catch.size + (@catch.size/10)  
end  
if @catch.bait\_id == 3  
@catch.points = @catch.size + (@catch.size/5)  
end  
@catch.update\_attributes(params[:catch])  
redirect\_to :action =\> ‘show’, :id =\> @catch  
else  
render :action =\> ‘edit’  
end  
end

By doing my points mod after the initial catch.update, then doing  
another catch.update it works OK. Not sure why I couldn’t just do my  
points processing before the first catch.update though – that’s how it  
should work. This method is invoked after the edit view (form) is  
submitted and the new score is input. I’m thinking that perhaps the new  
score was input by the form, but the @catch instance is getting the old  
score value to assign to points (from the db model) not the new one that  
was freshly input inside the params. I bet there’s a way to extract it  
from the params and insert the updated score into the params[:catch] so  
that a single update can be done. Any ideas?

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 5:55am UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/3 "2006-07-07T05:55:05Z")

</div>

Hey,  
I see you solved your problem, but you really should put that  
calculation in the model, not in the controller, then call it from the  
controller. This will keep your code clean and DRY, and makes it more  
MVCish/Railsish. You may want to just put it in a before\_save filter in  
your model, would be simple, assuming on all saves you want to calculate  
points. Look up callbacks in the api. Good Luck!

Chris C.  
[concentrationstudios.com](http://concentrationstudios.com)

Mike K. wrote:

> I have been playing with the cookbook type of tutorials building a fish  
> tournament scoring piece and am having a bit of a problem with a DB  
> field called “points” in my “catch” table that is not input by the user  
> but is calulated based on a “size” field that is input by the user.
> 
> I have the following in my catch\_controller.db  
> …
> 
> Where or in what method would I put similar code so that when someone  
> edits the “size” field of a record the “points” are properly tabulated?  
> The code above does not correctly work as it does for the new/create  
> function. Should this code be in an update method? What runs after the  
> edit view?
> 
> With default edit/update scaffolding I am seeing the “size” properly  
> updated but no effect on “points”. But if I then go back into the record  
> with the edit view and “submit” with no further changes the “points” are  
> magically updated. WTF is going on and how do I get my code to set the  
> points in the proper place? Clearly it does not belong in the edit view  
> …

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 4:18pm UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/4 "2006-07-07T16:18:39Z")

</div>

Mike K. wrote:

> Also I am wondering about my “solution” – there really should not have
> 
> > I see you solved your problem, but you really should put that  
> > calculation in the model, not in the controller, then call it from the  
> > controller. This will keep your code clean and DRY, and makes it more  
> > MVCish/Railsish. You may want to just put it in a before\_save filter in  
> > your model, would be simple, assuming on all saves you want to calculate  
> > points. Look up callbacks in the api. Good Luck!

If the scoring rules are fixed, you can just compute the points on  
demand, rather than saving them in the database. E.g. (in Catch)

BAIT\_SCALE\_FACTORS = [1.0, 1.0, 1.1, 1.2]

def points  
size \* BAIT\_SCALE\_FACTORS[bait\_id]  
end

(untested!) You might need to add some protection against size or  
bait\_id being undefined (but the same would be true of your original  
code)

Justin

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 2:25pm UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/5 "2006-07-07T14:25:00Z")

</div>

Thanks Chris – so move the points tabulation code (which I do want on  
all catch saves whether a new catch is entered or an existing one is  
edited/updated) to the model but still invokve it from the controller? I  
was under the impression actions not related to displaying data should  
be in the controller MVC-wise etc.

Will a before-save filter be invoked on both new and edit operations  
automatically or do I need to enable this? I’ll research the callbacks  
and before\_save later.

Also I am wondering about my “solution” – there really should not have  
to be 2 calls to update\_attributes should there? Does the before\_save  
get invoked through a callback when the update\_attributes or save  
methods are invoked? That would be a lot cleaner.

Thanks again,  
Mike

Chris C. wrote:

> Hey,  
> I see you solved your problem, but you really should put that  
> calculation in the model, not in the controller, then call it from the  
> controller. This will keep your code clean and DRY, and makes it more  
> MVCish/Railsish. You may want to just put it in a before\_save filter in  
> your model, would be simple, assuming on all saves you want to calculate  
> points. Look up callbacks in the api. Good Luck!
> 
> Chris C.  
> [concentrationstudios.com](http://concentrationstudios.com)

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 7:20pm UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/6 "2006-07-07T19:20:04Z")

</div>

Totally cool guys, I really appreciate all the pointers. The before-save  
callback works like a charm once the moronic programmer realizes the  
method goes in the model not the controller 😉 Justin I took your advice  
a step further, and put the bait scale factors into the bait table so it  
wouldn’t be hard-coded anywhere and would always be data-driven for  
other tournaments, bait types, and potential point scaling factors  
related to bait type.

The only thing that bites is my lack of understanding why the original  
piece of code in the 2nd post was required to have 2 updates. When I  
figure that out I’ll be much further down the road to understanding more  
about data passing and flow control in RoR.

Thanks Again, even an old OS programmer can find a little joy in this  
MVC stuff!

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 8:50pm UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/7 "2006-07-07T20:50:27Z")

</div>

Mike K. wrote:

> Totally cool guys, I really appreciate all the pointers. The before-save  
> callback works like a charm once the moronic programmer realizes the  
> method goes in the model not the controller 😉 Justin I took your advice  
> a step further, and put the bait scale factors into the bait table so it  
> wouldn’t be hard-coded anywhere and would always be data-driven for  
> other tournaments, bait types, and potential point scaling factors  
> related to bait type.
> 
> The only thing that bites is my lack of understanding why the original  
> piece of code in the 2nd post was required to have 2 updates. When I  
> figure that out I’ll be much further down the road to understanding more  
> about data passing and flow control in RoR.
> 
> Thanks Again, even an old OS programmer can find a little joy in this  
> MVC stuff!

Hi Mike!  
Glad to see it all worked out. It needed two updates because you  
updated them from the edit, then made the points, then updated again.  
If you did the points logic outside of that if statement you would have  
only needed the one.

–  
Chris

---

<div class="post-metadata">

**Author:** ![thekog](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/3da27b/32.png) [@thekog](https://www.ruby-forum.com/u/thekog)\
**Post date:** [July 7, 2006, 5:35pm UTC](https://www.ruby-forum.com/t/sequencing-control-with-edit-method-in-crud-examples/97436/8 "2006-07-07T17:35:33Z")

</div>

Justin thanks for that idea. However I think I am going to store them  
because there will be multiple fish per angler and ultimately I will be  
computing the angler’s total points from all catches etc. So for  
simplicity I really want to store the points although I like your  
approach better – being a 25+ year C programmer I don’t have my teeth  
around the Ruby syntax yet to do the obvious as you did with the points  
method and array. I think I’ll be doing that anyway to better isolate  
the common points logic.

Thanks!