# Booleans on new records

**URL:** <https://www.ruby-forum.com/t/booleans-on-new-records/190948>\
**Category:** Rails\
**Created:** [July 1, 2010, 1:36pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948 "2010-07-01T13:36:45Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![mercurius](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@mercurius](https://www.ruby-forum.com/u/mercurius)\
**Post date:** [July 1, 2010, 1:36pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948/1 "2010-07-01T13:36:45Z")

</div>

I have a array of Projects, which contains all Projects that have their  
‘display’ object set to 1 (true).

The problem is: when I create a new record, I tried changing the value  
of ‘display’ to false. This did not change the value as false when it  
entered the database. In contrast to this, when I edit an existing  
record and change the value of ‘display’ to false, it does.

I have raised the value of display before and after save to ensure it  
wasn’t (somehow) being changed at this stage.

My controller code can be seen here:

[http://pastie.org/1026480](http://pastie.org/1026480)

If there’s anything else you need to assist me with this, please let me  
know.

---

<div class="post-metadata">

**Author:** ![mercurius](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@mercurius](https://www.ruby-forum.com/u/mercurius)\
**Post date:** [July 1, 2010, 4:16pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948/2 "2010-07-01T16:16:04Z")

</div>

Pale H. wrote:

> My controller code can be seen here:
> 
> [http://pastie.org/1026480](http://pastie.org/1026480)

Oh, where to begin. Unless I’m completely daft, I see only one single  
line in your new method that belongs in a “new” action.

This one:  
@project = Project.new

Compare your method with what a new method should look like in a  
controller:

Example:

# GET /presentations/new

# GET /presentations/new.xml

def new  
@presentation = Presentation.new

```
respond_to do |format|
  format.html # new.html.erb
  format.xml { render :xml => @presentation }
end

```

end

The new method of a controller serves one purpose (following the single  
responsibility principal). That purpose is to GET the blank form. In  
other words the blank form is considered to be a resource that request  
using a GET method having a resource identifier similar to:

[http://example.com/presentations/new](http://example.com/presentations/new)

Take note that the @presentation object is used only for context to draw  
the form. When the form is submitted that instance of @presentation gets  
thrown away. A new instance is then initialized at the beginning of the  
“create” method as you can see in the following example:

Example:

# POST /presentations

# POST /presentations.xml

def create  
@presentation = Presentation.new(params[:presentation])

```
respond_to do |format|
  if @presentation.save
    flash[:notice] = 'Presentation was successfully created.'
    format.html { redirect_to(@presentation) }
    format.xml { render :xml => @presentation, :status => :created, 

```

:location =\> @presentation }  
else  
format.html { render :action =\> “new” }  
format.xml { render :xml =\> @presentation.errors, :status =\>  
:unprocessable\_entity }  
end  
end  
end

Your “new” method seems to be attempting to take on both  
responsibilities. I know there is such a thing as a post-back pattern,  
but the sorts of problems you’re having now are why that pattern is  
strongly discouraged in modern web application design.

Besides all that, if all you’re attempting to do is set a default state  
for your boolean fields when creating new records, then set a default  
state in your migration (… :default =\> false).

---

<div class="post-metadata">

**Author:** ![mercurius](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@mercurius](https://www.ruby-forum.com/u/mercurius)\
**Post date:** [July 1, 2010, 4:38pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948/3 "2010-07-01T16:38:26Z")

</div>

Robert W. wrote:

> Pale H. wrote:
> 
> > My controller code can be seen here:
> > 
> > [http://pastie.org/1026480](http://pastie.org/1026480)
> 
> Oh, where to begin. Unless I’m completely daft, I see only one single  
> line in your new method that belongs in a “new” action.

I can’t argue with that but this is not my site. Frankly, I don’t have  
the _time_ to make those kinds of amendments across the site, so in the  
light of consistency, I will not make one here. Perhaps when I obtain  
more time, I will return to this project and tighten this code. I am,  
equally, not happy with this method. Despite this, it _certainly_ works.

> This one:  
> @project = Project.new
> 
> Compare your method with what a new method should look like in a  
> controller:

Thank you, I’m well aware what is generated by the scaffolding.  
Digression…

> Example:
> 
> # GET /presentations/new
> 
> # GET /presentations/new.xml
> 
> def new  
> @presentation = Presentation.new
> 
> ```
> respond_to do |format|
> format.html # new.html.erb
> format.xml { render :xml => @presentation }
> end
> 
> ```
> 
> end
> 
> The new method of a controller serves one purpose (following the single  
> responsibility principal). That purpose is to GET the blank form. In  
> other words the blank form is considered to be a resource that request  
> using a GET method having a resource identifier similar to:
> 
> [http://example.com/presentations/new](http://example.com/presentations/new)
> 
> Take note that the @presentation object is used only for context to draw  
> the form. When the form is submitted that instance of @presentation gets  
> thrown away. A new instance is then initialized at the beginning of the  
> “create” method as you can see in the following example:
> 
> Example:
> 
> # POST /presentations
> 
> # POST /presentations.xml
> 
> def create  
> @presentation = Presentation.new(params[:presentation])
> 
> ```
> respond_to do |format|
> if @presentation.save
> flash[:notice] = 'Presentation was successfully created.'
> format.html { redirect_to(@presentation) }
> format.xml { render :xml => @presentation, :status => :created, 
> 
> ```
> 
> :location =\> @presentation }  
> else  
> format.html { render :action =\> “new” }  
> format.xml { render :xml =\> @presentation.errors, :status =\>  
> :unprocessable\_entity }  
> end  
> end  
> end
> 
> Your “new” method seems to be attempting to take on both  
> responsibilities. I know there is such a thing as a post-back pattern,  
> but the sorts of problems you’re having now are why that pattern is  
> strongly discouraged in modern web application design.

I’m well aware that this is not the correct method to invoke this  
action.

> Besides all that, if all you’re attempting to do is set a default state  
> for your boolean fields when creating new records, then set a default  
> state in your migration (… :default =\> false).

Again, I’m well aware that default values can be set in migrations.

Now, I realised that a lib file was being included. One that the  
developer prior to myself had (for some reason) put in and had written  
himself for a generator. On initialising this, it sets the value of  
‘display’ to true regardless of the state in which it is.

Conclusively, check your inclusions if the site you’re working on was  
not created by yourself.

---

<div class="post-metadata">

**Author:** ![mercurius](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@mercurius](https://www.ruby-forum.com/u/mercurius)\
**Post date:** [July 1, 2010, 5:43pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948/4 "2010-07-01T17:43:54Z")

</div>

As I have said, I’ve realised the problem is not with the controller  
code that’s under discussion but with a lib file that takes precedence  
over it. Conversing more on the matter would be an exercise in futility,  
however.

That said, Marnen & Robert, I will read that Wiki and have absorbed what  
you’ve said - thanks.

---

<div class="post-metadata">

**Author:** ![mercurius](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@mercurius](https://www.ruby-forum.com/u/mercurius)\
**Post date:** [July 1, 2010, 5:34pm UTC](https://www.ruby-forum.com/t/booleans-on-new-records/190948/5 "2010-07-01T17:34:47Z")

</div>

Pale H. wrote:

> Robert W. wrote:
> 
> > Pale H. wrote:
> > 
> > > My controller code can be seen here:
> > > 
> > > [http://pastie.org/1026480](http://pastie.org/1026480)
> > 
> > Oh, where to begin. Unless I’m completely daft, I see only one single  
> > line in your new method that belongs in a “new” action.

I don’t have a lot to say about the original problem that Robert didn’t  
already mention, but I do think I should mention a couple of things  
about development practice that will save you a lot of grief going  
forward.

> I can’t argue with that but this is not my site.

The moment you start working on it, it is in a sense your site. Take  
ownership of the code and do the right things.

> Frankly, I don’t have  
> the _time_ to make those kinds of amendments across the site, so in the  
> light of consistency, I will not make one here.

That is generally poor reasoning. It is usually a good idea to “fix  
broken windows” – that is, fix obviously bad code as you come across  
it; it will save time and incrementally improve the quality of the  
codebase. You don’t have to make a grand refactoring sweep through the  
whole project if you don’t have time; just fix bad code where it annoys  
you. See [http://c2.com/cgi/wiki?FixBrokenWindows](http://c2.com/cgi/wiki?FixBrokenWindows) .

Delaying fixes that would help you, just in order to keep some larger  
“consistency”, is generally not a great idea.

> Perhaps when I obtain  
> more time, I will return to this project and tighten this code. I am,  
> equally, not happy with this method. Despite this, it _certainly_ works.

If it worked, presumably you wouldn’t be having problems with it. If  
you can’t maintain it as is, then fix it.

## Best,

Marnen Laibow-Koser  
[http://www.marnen.org](http://www.marnen.org)  
removed\_email\_address@domain.invalid