Error when updating with an image file

Rails
1

NOOB ALERT

Now I warned you, here’s the problem that’s been getting me mad for
hours

I’ve got a model for content I’m calling “lead”. It has a title, a text
and
an image used as a background.

I’m not using paperclip or CarrierWave to handle the image file (and I
don’t want to, one of my needs here is to learn how this all works).
I’m using this function to upload the file (it comes directly from the
rails guides) :

def upload
if params[:lead][:illustration]
uploaded_io = params[:lead][:illustration]

  File.open(Rails.root.join('app', 'assets', 'images',

uploaded_io.original_filename), ‘wb’) do |file|
file.write(uploaded_io.read)
end

  @lead.illustration = "#{uploaded_io.original_filename}"
end

end

When creating a “lead”, everything goes fine with create:

def create
@lead = Lead.new( params[:lead] )

upload

if @lead.save
  flash[:success] = "Lead successfully added."
  redirect_to @lead
else
  redirect_to root_path
end

end

The “lead” gets saved, I can use it. So far, so good.

Now with the problem (remember the NOOB ALERT).
Updating a lead without modifying the image goes fine, but updating with
a
new image returns this error:

NoMethodError in LeadsController#update

undefined method `name’ for nil:NilClass

and

app/controllers/leads_controller.rb:45:in `update’

Here’s my update function:

def update
@lead = Lead.find_by_id( params[:id] )

upload

if @lead.update_attributes!(params[:lead])
  flash[:success] = "Leaderboard successfully updated."
  redirect_to @lead
else
  render action: "edit"
end

end

Basically the same as create. I’ve been googling and going back and
forth
for hours and I didn’t get to solve this. Any help would be more than
welcome.

2

On 6 December 2012 09:43, Jean-David [email protected] wrote:

guides) :
@lead.illustration = “#{uploaded_io.original_filename}”
if @lead.save
Now with the problem (remember the NOOB ALERT).
app/controllers/leads_controller.rb:45:in `update’
The error says that you are calling method ‘name’ for something that
is nil at line 45 in leads_controller.rb.

  flash[:success] = "Leaderboard successfully updated."
  redirect_to @lead
else
  render action: "edit"
end

end

Basically the same as create. I’ve been googling and going back and forth
for hours and I didn’t get to solve this. Any help would be more than
welcome.

Unfortunately you have not told us which is line 45.

Colin

3

I supposed it was obvious… ; )

Seriously, line 45 is in the update function:

40 def update
41 @lead = Lead.find_by_id( params[:id] )
42
43 upload
44
45 if @lead.update_attributes!(params[:lead])
46 flash[:success] = “Leaderboard successfully updated.”
47 redirect_to @lead
48 else
49 render action: “edit”
50 end
51 end

Le jeudi 6 dcembre 2012 11:05:59 UTC+1, Colin L. a crit :

4

On 6 December 2012 10:16, Jean-David [email protected] wrote:

Please don’t top post, it makes it difficult to follow the thread.
Insert you reply inline at appropriate points in the previous message.
Thanks

I supposed it was obvious… ; )

Not sure why it would be obvious.

Seriously, line 45 is in the update function:

40 def update
41 @lead = Lead.find_by_id( params[:id] )
42
43 upload
44
45 if @lead.update_attributes!(params[:lead])

It is also better not to use html as now the fact that you highlighted
the line above is not visible.
Have you checked that @lead is not nil?
Have a look at the Rails Guide on Debugging to get lots of ideas on
how to debug your code. Start by looking in log/development.log to
check that the attributes are being passed correctly. Then, for
example, use the debugger to break into the code and check what is
going on or put diagnostic puts statements in to inspect the data.

Colin

5

Le jeudi 6 dcembre 2012 13:23:58 UTC+1, Colin L. a crit :

return “#{uploaded_io.original_filename}”
instead of
@lead.illustration = upload
in “create”, and that wont work.

Can you post your create and update methods as you now have them so I
can see what you are doing.

Sure, here goes :

def create
@lead = Lead.new( params[:lead] )

@lead.illustration = upload_image

if @lead.save
  flash[:success] = "Leaderboard successfully added."
  redirect_to @lead
else
  redirect_to root_path
end

end

def update
@lead = Lead.find_by_id( params[:id] )

params[:lead][:illustration] = upload_image

if @lead.update_attributes( params[:lead] )
  flash[:success] = "Leaderboard successfully updated."
  redirect_to @lead
else
  render action: "edit"
end

end

def upload_image
if params[:lead][:illustration]
uploaded_io = params[:lead][:illustration]

  File.open(Rails.root.join('app', 'assets', 'images',

uploaded_io.original_filename), ‘wb’) do |file|
file.write(uploaded_io.read)
end

  return "#{uploaded_io.original_filename}"
end

end

6

On 6 December 2012 13:43, Jean-David [email protected] wrote:

After finding this out I tried to set

end

end

def update
@lead = Lead.find_by_id( params[:id] )

params[:lead][:illustration] = upload_image

You said that doing @lead.illustration = upload_image (presumably at
this point) did not work. It should do, provided that
params[:lead][:illustration] is not present. If it is then the value
from upload_image will be overwritten by the value from params when
you call update_attributes. Another possibility is that if the
illustration is the only field being changed then update_attributes
may not actually save the record (as it does not think anything has
changed).

Probably leaving it as you have it is the simplest solution.

Colin

7

On 6 December 2012 12:11, Jean-David [email protected] wrote:

@lead.illustration = upload

In “update”, this wont work. I need to set:
params[:lead][:illustration] = upload
and the update goes fine.

After finding this out I tried to set
params[:lead][:illustration] = upload
instead of
@lead.illustration = upload
in “create”, and that wont work.

Can you post your create and update methods as you now have them so I
can see what you are doing.

Colin

8

On Dec 6, 2012, at 9:11 AM, Colin L. wrote:

“upload” now returns this:
params[:lead][:illustration] = upload
@lead = Lead.new( params[:lead] )

illustration is the only field being changed then update_attributes
may not actually save the record (as it does not think anything has
changed).

Probably leaving it as you have it is the simplest solution.

Colin

Jean-David,

Here’s a bit of code from an old project of mine:

def update
data = params[:product].delete(‘data’) # HashWithIndifferentAccess
still needs the actual key type to .delete
begin
@product = Product.find(params[:id], :conditions => { :virtual =>
true })

  unless data.blank?          # i.e., not replacing image
    content = data.read
    if content.blank?
      flash[:error] = "Selected upload file was empty"
      redirect_to :action => 'edit'
      return
    end
    @product.image_size = ImageSizer.of_blob(content).size
    filename = Product.get_local_image_name data.original_filename
    File.open(File.join(RAILS_ROOT, 'public', filename), 'wb') do

|f|
f.write content
end
@product.image = filename
end

  respond_to do |format|
    if @product.update_attributes(params[:product])

end

Note that I am removing the ‘data’ key from the attributes hash
params[:product] so that it isn’t used in the .update_attributes call
later. Perhaps you need to remove the ‘illustration’ since you’ve
already handled that portion of the update.

If you know that the illustration is changed, but ActiveRecord doesn’t,
then perhaps you need to call @lead.illustration_will_change! to inform
AR that the attribute is dirty and needs to be written out.

-Rob

9

Colin

I too guess it should do but I will leave it this way for now.

Thx Colin.

10

Le jeudi 6 dcembre 2012 17:14:47 UTC+1, Rob B. a crit :

and the update goes fine.
Sure, here goes :
redirect_to root_path
params[:lead][:illustration] is not present. If it is then the value
Jean-David,
unless data.blank? # i.e., not replacing image
end
later. Perhaps you need to remove the ‘illustration’ since you’ve already
handled that portion of the update.

If you know that the illustration is changed, but ActiveRecord doesn’t,
then perhaps you need to call @lead.illustration_will_change! to inform AR
that the attribute is dirty and needs to be written out.

-Rob

Thank you Rob, I’ll try to put that in my own sauce (that’s an
approximate
translation for french " ma sauce" ; )