My second problem is:
Listing users, and deleting them doesn''t work.
If I try to list user, i just get this list:
User Delete
User Delete
User Delete
User Delete
I''m using this code in the login_controller:
def list_users
@all_users = User.find(:all)
end
def delete_user
@id = params[:id]
if id && user = User.find(id)
begin
User.destroy
flash[:notice] = "User #{user.name} deleted"
rescue
flash[:notice] = "Can''t delete that user"
end
end
redirect_to_index(:action => :list_users)
end
and the list_users view looks like this:
<% for users in @all_users -%>
<tr>
<td><%= User.name %></td>
<td><%= link_to ''Delete'', { :action =>
''delete_user'', :id => id },
:confirm => ''Are you sure?'' %></td>
</tr>
<% end -%>
trying to delete a user gives:
ActiveRecord::RecordNotFound in Login#delete_user
Couldn''t find User with ID=30034968
By the way, I got this errormessage by clicking:
<a href="/login/delete_user/29113692" onclick="return
confirm(''Are you
sure?'');">Delete</a>
The user ID''s seem to be messed up, and I don''t see what I did
wrong...
Johan.
--
Posted via http://www.ruby-forum.com/.
Hi,
try
<% for user in @all_users -%>
<tr>
<td><%= user.name %></td>
<td><%= link_to ''Delete'', { :action
=> ''delete_user'',
:id => user },
:confirm => ''Are you sure?'' %></td>
</tr>
<% end -%>
HTH, Beate
Thank you, listing users is working now. But I still get an error message if I try to delete one: --> http://localhost:3001/login/delete_user/1>ActiveRecord::RecordNotFound in Login#delete_user >Couldn''t find User with ID=30085920Apparantly, I should have used user.name instead of User.name... Could you explain me why I shouldn''t use a capital U in User.name? Thank you, Johan. -- Posted via http://www.ruby-forum.com/.
2006/2/5, Johan Van Mol <johan.van.mol@gmail.com>:> Thank you, listing users is working now. > But I still get an error message if I try to delete one: > > --> http://localhost:3001/login/delete_user/1 > > >ActiveRecord::RecordNotFound in Login#delete_user > >Couldn''t find User with ID=30085920there is a typo in your controller. This does not work: @id = params[:id] if id && user = User.find(id) Try this: @id = params[:id] if @id && user = User.find(@id)> Apparantly, I should have used user.name instead of User.name... > Could you explain me why I shouldn''t use a capital U in User.name?You can''t use "User", as this is not definded in the view: <% for user in @all_users -%> I myself visualize this like "For every single user in @users", so "user" is my variable. Beate
Your suggested code didn''t work.
I don''t get an error message anymore,
but I get a flash notice: actionlist_users.
And the user doesn''t get deleted.
However, I managed to fix my problem:
def delete_user
id = params[:id]
if id && user = User.find(id)
begin
user.destroy
flash[:notice] = "User #{user.name} deleted"
rescue
flash[:notice] = "Can''t delete that user"
end
end
redirect_to(:action => :list_users)
end
Again, I typed User.destroy instead of user.destroy.
But you can use User.find instead of user.find.
I still don''t really get it: when do you have to use capital characters
/ when not?
Beate, thank you for helping me with my 2 problems!
Johan
--
Posted via http://www.ruby-forum.com/.
2006/2/5, Johan Van Mol <johan.van.mol@gmail.com>:> Again, I typed User.destroy instead of user.destroy. > But you can use User.find instead of user.find. > I still don''t really get it: when do you have to use capital characters > / when not?User.find(...) means the model, i.e. find all or the first (depending on your find) User from the table. user.destroy means the user set in "user = User.find(id)", a special user. But i can understand you, this was a little bit confusing to me in the beginning, too. Beate
Lowercase "user" is an instance variable... you can use it if you''ve created or retrieved a User into it (though you could also retrieve any other object into it or you could call the variable "rumplestiltskin"... but that would be more confusing). The uppercase "User" is the actual class. So, when you do User.destroy you are calling a "class method", meaning the method is not tied to an instance (a "static" method in Java). This shouldn''t work because "destroy" is not a class method. When you do user.destroy you are calling an "instance method", meaning the method is tied to a specific instance of User... and it does the work declared in that method *to* the instance you call it on. This should delete the row in the db that corresponds to the User object held in variable "user". The destroy method makes sense as an instance method, because you''re destroying a specific instance. The find method, on the other hand, makes sense as a class method because you don''t have an instance to call find on until you call find! Hope that helps. b Johan Van Mol wrote:> Your suggested code didn''t work. > I don''t get an error message anymore, > but I get a flash notice: actionlist_users. > And the user doesn''t get deleted. > > However, I managed to fix my problem: > > def delete_user > id = params[:id] > if id && user = User.find(id) > begin > user.destroy > flash[:notice] = "User #{user.name} deleted" > rescue > flash[:notice] = "Can''t delete that user" > end > end > redirect_to(:action => :list_users) > end > > Again, I typed User.destroy instead of user.destroy. > But you can use User.find instead of user.find. > I still don''t really get it: when do you have to use capital characters > / when not? > > Beate, thank you for helping me with my 2 problems! > > Johan > >
It helps a lot!
Everything is clear now.
So this code:
id = params[:id]
if id && user = User.find(id)
begin
user.destroy
flash[:notice] = "User #{user.name} deleted"
actually does this:
It creates an instance variable id, based on the specified parameters.
If this id was created, a user instance variable is created, based on a
User in the User class, with the specified id.
Then this user instance variable (thus the User with the id you
specified) is destroyed, and a flash message appears.
And by typing in User.destroy - if this method existed - ,you would do
something like deleting all users?
Thank you all for your help! I love the RoR community :-)
Johan.
--
Posted via http://www.ruby-forum.com/.
Johan Van Mol wrote:> It helps a lot! > Everything is clear now. > > So this code: > > id = params[:id] > if id && user = User.find(id) > begin > user.destroy > flash[:notice] = "User #{user.name} deleted" > > actually does this: > > It creates an instance variable id, based on the specified parameters. > If this id was created, a user instance variable is created, based on a > User in the User class, with the specified id. > Then this user instance variable (thus the User with the id you > specified) is destroyed, and a flash message appears. > > And by typing in User.destroy - if this method existed - ,you would do > something like deleting all users?Well, if User.destroy existed, it might do something like that... but it doesn''t. You''ve got it though... use class methods (defined by doing "def self.methodname...") to do stuff that doesn''t make sense to have attached to a single instance and use instance methods to do stuff that does. b