I''m having trouble using an application helper and understanding how I
should make it work throughout my application - so if you can help me
with this I''ll be overcoming a big hurdle in my learning.
Here''s the helper method;
[code=]# application_helper.rb
def user_photo
if @user.photo?
return @user.photo.public_filename(:thumb)
else
return ''rails.png''
end
end[/code]
Pretty simple. I understand what it does, and it works just fine in my
show action in the user controller;
[code=]# user_controller.rb
def show
@user = User.find(params[:id])
end[/code]
[code=]# show.html.erb
<h2><%= @user.login %></h2>
<div class="photo">
<%= image_tag user_photo %>
</div>
<div class="details">
<p>Email: <%= @user.email %></p>
<p>Joined: <%= @user.created_at.to_s(:long) %></p>
<p>Posts: <%= @user.posts.count %></p>
</div>[/code]
However, I want this helper to work elsewhere in the app, such as a
_post partial, which obviously is called on the Post index and show
actions, etc. But because the user_photo method uses the @user instance
variable, I need to make it work when @user isn''t set in the current
controller, e.g. the posts index action (if I use the user_photo in the
_post partial on the post index action, I inevitably get a nil object
because @user.photo doesn''t exist);
[code=]def index
@posts = Post.list(params[:page])
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => @posts }
end
end[/code]
I''m already pulling @posts on the post index (and there is a
''post.user.photo'' in every ''post'' in
@posts); do I need to define the
@user instance variable in all the necessary controller actions, by
doing something like this;
[code=]def index
@posts = Post.list(params[:page])
@user = "post.user for every post in @posts" # something along those
lines...
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => @posts }
format.rss { render :rss => @posts }
end
end[/code]
Or can I do this in a different way which doesn''t involve defining
@user
in every controller action ?
--
Posted via http://www.ruby-forum.com/.
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why not just pass the object to your helper method as an argument? def user_photo(user) user.photo? ? user.photo.public_filename(:thumb) : ''default.png'' end then in your view template just use: <%= user_photo(@user) %> Mike On 2/29/08, Neil Cauldwell <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > I''m having trouble using an application helper and understanding how I > should make it work throughout my application - so if you can help me > with this I''ll be overcoming a big hurdle in my learning. > > Here''s the helper method; > > [code=]# application_helper.rb > > def user_photo > if @user.photo? > return @user.photo.public_filename(:thumb) > else > return ''rails.png'' > end > end[/code] > > Pretty simple. I understand what it does, and it works just fine in my > show action in the user controller; > > [code=]# user_controller.rb > > def show > @user = User.find(params[:id]) > end[/code] > > [code=]# show.html.erb > > <h2><%= @user.login %></h2> > <div class="photo"> > <%= image_tag user_photo %> > </div> > <div class="details"> > <p>Email: <%= @user.email %></p> > <p>Joined: <%= @user.created_at.to_s(:long) %></p> > <p>Posts: <%= @user.posts.count %></p> > </div>[/code] > > However, I want this helper to work elsewhere in the app, such as a > _post partial, which obviously is called on the Post index and show > actions, etc. But because the user_photo method uses the @user instance > variable, I need to make it work when @user isn''t set in the current > controller, e.g. the posts index action (if I use the user_photo in the > _post partial on the post index action, I inevitably get a nil object > because @user.photo doesn''t exist); > > [code=]def index > @posts = Post.list(params[:page]) > > respond_to do |format| > format.html # index.html.erb > format.xml { render :xml => @posts } > end > end[/code] > > I''m already pulling @posts on the post index (and there is a > ''post.user.photo'' in every ''post'' in @posts); do I need to define the > @user instance variable in all the necessary controller actions, by > doing something like this; > > [code=]def index > @posts = Post.list(params[:page]) > @user = "post.user for every post in @posts" # something along those > lines... > > respond_to do |format| > format.html # index.html.erb > format.xml { render :xml => @posts } > format.rss { render :rss => @posts } > end > end[/code] > > Or can I do this in a different way which doesn''t involve defining @user > in every controller action ? > -- > Posted via http://www.ruby-forum.com/. > > > >--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Thanks Mike. I''ve tried your suggestion but it doesn''t work - definitely due to my lack of understanding. On the posts index, I get the following; You have a nil object when you didn''t expect it! The error occurred while evaluating nil.photo? I replaced the previous helper with your much more streamlined version. I also put the <%= user_photo(@user) %> in place of <%= link_to image_tag user_photo %> in the _post partial (I''ll put the link_to and image_tag in when it''s all working). But the post index action isn''t passing a @user variable (as seen in the original post, above), and the _post partial currently works by calling ''post.user'', or ''post.created_at.to_s(:short)'' local variables on the @posts :collection passed on the index view; <h2>Latest Posts</h2> <%= render :partial => ''post'', :collection => @posts %> <%= will_paginate @posts %> How does the @user variable fit in to this? Wouldn''t it need to be defined in either the application helper or the Posts index action? -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
On Feb 29, 11:55 am, Neil Cauldwell <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > How does the @user variable fit in to this? Wouldn''t it need to be > defined in either the application helper or the Posts index action? >If you want to display a photo that is associated with a user, you will need to have access to the user object for that photo. Looking at your original post, it appears that a post belongs to a user - is this correct? If so, in the posts index action for example, you would call Mike''s suggested method as user_photo(post.user). What this is doing is passing the user object associated with that post through to the user_photo helper. Regards Robin --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe@googlegroups.com For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Robin, thanks for the explanation. A user has many posts, and a post belongs to a user. I''m still getting an error from the _post partial; "undefined method `photo?'' for #<User:0x3656eec>" application_helper.rb def user_photo(user) user.photo? ? user.photo.public_filename(:thumb) : ''rails.png'' end _post.html.erb <%= user_photo(post.user) %> I don''t understand why I''m getting the error, because I can link to a post.user.photo as follows; <%= link_to image_tag(post.user.photo.public_filename(:thumb)), user_path(post.user) %> And that successfully passes the ''post.user'' to the user_path. Surely I''m misunderstanding how the helper uses the post.user to fetch the photo... -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---