Error when updating with an image file

[Jean-David]

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.

[Colin Law]

The error says that you are calling method 'name' for something that
is nil at line 45 in leads_controller.rb.

>
>
> 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.

Unfortunately you have not told us which is line 45.

Colin

[Jean-David]

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 

[Colin Law]

On 6 December 2012 10:16, Jean-David <jeandav...@gmail.com> 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

[Colin Law]

On 6 December 2012 12:11, Jean-David <jeandav...@gmail.com> wrote:
> ...
> Thanks for the advise. Logging led me to a solution, but I don't
> really understand what's going on under the hood.
>
> Here's my solution:
>
> "upload" now returns this:
> return "#{uploaded_io.original_filename}"
>
> In "create", I set:
> @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

[Jean-David]

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

Colin

[Colin Law]

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

[Rob Biedenharn]

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

>
>>
>> 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
>>
>>
>>
>>>
>>> Colin
>

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[Jean-David]

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

[Jean-David]

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

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

Thx Colin.