Error of undefined method

Hi all, I have very basic error that i have no idea how to show

I have user table
id
name
add
phone number

then i select all in user table
using => @users = User.all

=> @users.name

it gives me undefined method name Array<…>

Please give me some advice…

Thanks

Hi!

The method User.all returns an Array of users, not a single user.

I think you have to iterate over the array, using each.

@users.each { |u| u.name }

Everaldo

@users.all basically returns “array” of users

so you have to iterate through this array

@users.each do |user|
puts user.name
end

tom

On Jun 20, 2011, at 18:33 , Yennie wrote:

using => @users = User.all

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Tomas Meinlschmidt, MS {MCT, MCP+I, MCSE, AER}, NetApp Filer/NetCache

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thanks

On Mon, Jun 20, 2011 at 12:38 PM, Everaldo G.
[email protected]wrote:

Thanks


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On 20 June 2011 17:53, joanne ta [email protected] wrote:

and it causes undefined method image
What does it say has not got a method image? It is always a good idea
to post the complete error message (use copy/paste rather than
re-typing it). If it says the nil has not got the method then your
call of Picture.where has not found a record.

Colin

I have other undefined method when i combine the code above together

<%@users = User.all%>
<[email protected] do |u|%>
<%u.culture_id%>

<% @pic= Picture.where(:phrase_id => :route , :culture_id =>
u.culture_id).first%>

My picture <%= @pic.image%>

and it causes undefined method image

please give me advices… thank you so much

Joanne

On Mon, Jun 20, 2011 at 12:48 PM, joanne ta [email protected]
wrote:

id
it gives me undefined method name Array<…>

Please give me some advice…

Thanks

Joanne

the error is undefined method `image’ for nil:NilClass

On Mon, Jun 20, 2011 at 2:42 PM, Colin L. [email protected]
wrote:

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You don’t have an <% end %> to close the <% @users.each %> block in the
code
you included, so my guess is that your u variable is already out of
scope by
the time you call u.image.

Hi,

Few things here:

  1. Would be good if you can paste full code from the beginning of the
    loop
    till the place where you render picture
  2. It is not a good practice to set instance variables in the views, set
    them in controller instead
  3. It is not a good practice to do finds in views, if you want to fetch
    a
    picture for the user, it’s better to define a relationship between
    picture
    and user models. And then do something like this in the controller -
    @users
    = User.includes(:picture).all

Hope this helps.

On 20 June 2011 20:08, joanne ta [email protected] wrote:

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

the error is undefined method `image’ for nil:NilClass

So what does that mean (see my previous post)?

Colin

end

<% end %>

error is

You have a nil object when you didn’t expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.each

Extracted source (around line #79):

76:


77: <%= image_tag url_for(:controller => “/users”, :action =>
“index”),
:width => “25px”, :height => “25px”%>
78:
79: <[email protected] do |c|%>
80: <%= c.image%>
81: <% end %>
82:

please give me some advices…

My controller:

def index
@users= User.all

@users.each do |p|
@pic= Picture.where(:phrase_id => :route , :culture_id =>

p.culture_id).first
send_data @pic.image, :type => ‘image/gif’, :disposition =>
‘inline’
end
end

in View

<%= image_tag url_for(:controller => "/users", :action => "index"), :width => "25px", :height => "25px"%>

<[email protected] do |c|%>
<%= c.image%>
<% end %>

please give me some advices…

thanks
Joanne

it does not work, it is complaining other error

NoMethodError (undefined method image' for [nil]:Array): app/controllers/patients_controller.rb:27:inblock in index’
app/controllers/patients_controller.rb:25:in each' app/controllers/patients_controller.rb:25:inindex’

On Tue, Jun 21, 2011 at 9:57 AM, Chirag S.
[email protected]wrote:

end
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Your index action should be something like this:

def index
@users= User.all
@pic = []

@users.each do |p|
@pic << Picture.where(:phrase_id => :route , :culture_id =>
p.culture_id).limit(1)
end
end

Oh yes… sorry about that.
I assumed that you will find picture for every query.

You can try this instead:
def index
@users= User.all
@pic = []

@users.each do |p|
@pic << Picture.where(:phrase_id => :route , :culture_id =>
p.culture_id).limit(1)
end
@pic.compact!
end

by calling compact! on the array, we will eliminate all nil object.

On another note, are you sure, this is what you want to do? If you have
100
users, it will fire 100 sql queries which is not good.

On Tue, Jun 21, 2011 at 7:42 PM, joanne ta [email protected] wrote:

end
For more options, visit this group at
Yen


Chirag
http://sumeruonrails.com

Can you paste what you have in your index method?
You should not be getting this error because we have already defined
@pic as
an empty array.

On Tue, Jun 21, 2011 at 8:10 PM, joanne ta [email protected] wrote:

@users= User.all

The error occurred while evaluating nil.compact!):

On Tue, Jun 21, 2011 at 7:42 PM, joanne ta [email protected] wrote:

On Tue, Jun 21, 2011 at 9:57 AM, Chirag S. <

p.culture_id).limit(1)
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Chirag
http://sumeruonrails.com

On Tue, Jun 21, 2011 at 10:27 AM, Chirag S.
[email protected]wrote:

p.culture_id).limit(1)
end
@pic.compact!
end

by calling compact! on the array, we will eliminate all nil object.

On another note, are you sure, this is what you want to do? If you have 100
users, it will fire 100 sql queries which is not good.

Yes i think i have that problem as well because if i remove "@users.each
do |p| "
and then it will cause undefined method of culture_id…
plus when i call @pic.compact! , it gives me

NoMethodError (You have a nil object when you didn’t expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.compact!):
app/controllers/patients_controller.rb:29:in `index’

what is mean? cuz i want to display picture on the browser too…

please help… thank you very much

Joanne

Can you paste what you have in your index method?

You should not be getting this error because we have already defined @pic
as an empty array.

@pic.compact!

p.culture_id).limit(1)
do |p| "
please help… thank you very much

app/controllers/patients_controller.rb:27:in `block in index’

def index
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  1. Remove the send_data line, it isn’t required.
  2. Can you check if there are any records in your pictures table? Right
    now
    it looks like it is returning nil.

On Tue, Jun 21, 2011 at 8:35 PM, joanne ta [email protected] wrote:

send_data @pic.image, :type => 'image/png', :disposition => 'inline'

p.culture_id).limit(1)
do |p| "
please help… thank you very much

app/controllers/patients_controller.rb:27:in `block in index’

def index
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Chirag
http://sumeruonrails.com

@users.each do |user|

An array of pictures doesn’t have an “image” attribute.

because i want to take a value “image” from Picture model
what can i do … I am really stuck now…

thanks

Joanne

Hassan S. ------------------------ [email protected]
http://about.me/hassanschroeder
twitter: @hassan


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