Hi all,
I have the following file below which is a controller inteneded to
maintain non persisted data. It has two routes defined by
''gather'' and
''show''. Gather displays a form and show, obviously, shows the
non
persisted data. My problem is that initialize is called every time
gather and show are called causing me to lose the data contained in @td.
How do I fix this?
Thanks,
Cris
class TransientController < ApplicationController
def initialize
@td = TransientData.new
puts ''initialize called''
end
def gather
puts ''gather''
respond_to do |format|
format.html # gather.html.erb
end
end
def show
puts ''show ''
@td.firstname=(params[:firstname])
@td.lastname=(params[:lastname])
respond_to do |format|
format.html #show.html.erb
end
end
end
class TransientData
def initialize
@firstname=''default1''
@lastname=''default2''
end
attr_accessor :firstname, :lastname
end
--
Posted via http://www.ruby-forum.com/.
I tried with statics and that did not work. It is as if rails
completely unloads the controller between invocations.
class TransientController < ApplicationController
def initialize
puts ''initialize called''
end
def gather
puts ''gather''
respond_to do |format|
format.html # index.html.erb
end
end
def show
puts ''show ''
TransientData.firstname=(params[:firstname])
TransientData.lastname=(params[:lastname])
respond_to do |format|
format.html #show.html.erb
end
end
end
class TransientData
@@firstname=''default1''
@@lastname=''default2''
def self.firstname()
@@firstname
end
def self.lastname()
@@lastname
end
def self.lastname=(name)
@@lastname = name
end
def self.firstname=(name)
@@firstname=name
end
end
Cris Shupp wrote:> Hi all,
>
> I have the following file below which is a controller inteneded to
> maintain non persisted data. It has two routes defined by
''gather'' and
> ''show''. Gather displays a form and show, obviously,
shows the non
> persisted data. My problem is that initialize is called every time
> gather and show are called causing me to lose the data contained in @td.
> How do I fix this?
>
> Thanks,
>
> Cris
>
>
> class TransientController < ApplicationController
>
> def initialize
> @td = TransientData.new
> puts ''initialize called''
> end
>
> def gather
> puts ''gather''
> respond_to do |format|
> format.html # gather.html.erb
> end
> end
>
> def show
> puts ''show ''
> @td.firstname=(params[:firstname])
> @td.lastname=(params[:lastname])
> respond_to do |format|
> format.html #show.html.erb
> end
> end
>
> end
>
> class TransientData
>
> def initialize
> @firstname=''default1''
> @lastname=''default2''
> end
> attr_accessor :firstname, :lastname
> end
--
Posted via http://www.ruby-forum.com/.
Cris Shupp wrote:> I tried with statics(They''re just called "class variables" in Ruby.)> and that did not work. It is as if rails > completely unloads the controller between invocations.In development mode, it does. And in production, there''s no guarantee that you''ll get the same server instance as last time, so you can''t really rely on class variables in the controller. You might be able to rig up something in a model... But this smells funny. What exactly are you trying to do here? In most cases, if data is worth saving, it''s worth putting in the DB. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Hi Marnen. Thanks for your reply. Here is what I am trying to do... We are trying to use mongrel as a job execution engine and use rails for the front end GUI. We intend to have an initial configuration screen where the administrator will populate various properties in form for use in determine how the various jobs will run. Whenever the ''system'' (and system will consist of more than, but include, mongrel) is brought down for maintenance we want the admins to reexamine these properties so we want them ''forgotten'' between maintenance windows. Scalability is not an issue here as only a handful of admins will use the tool, (thus no clustering will be involved) and I expect statics will work. In fact, when I moved the TransientData class to a file called library.pl in the lib directory and required it in the controller it did (finally) work. If the right approach is to use an active record, despite the lack of need for persistence, can one create an active record and declare it to be a singleton (i.e. never more than one row in the database)? Can one do the equivalent of a j2ee startup bean and have a mongrel run a job upon startup of the server so I could delete that singleton? The idea of being able to use an active record and have all of the validation goodies does appeal to me. Thanks, Cris Marnen Laibow-Koser wrote:> Cris Shupp wrote: >> I tried with statics > > (They''re just called "class variables" in Ruby.) > >> and that did not work. It is as if rails >> completely unloads the controller between invocations. > > In development mode, it does. And in production, there''s no guarantee > that you''ll get the same server instance as last time, so you can''t > really rely on class variables in the controller. You might be able to > rig up something in a model... > > But this smells funny. What exactly are you trying to do here? In most > cases, if data is worth saving, it''s worth putting in the DB. > > Best, > -- > Marnen Laibow-Koser > http://www.marnen.org > marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org-- Posted via http://www.ruby-forum.com/.
Cris Shupp wrote:> Hi Marnen. > > Thanks for your reply. Here is what I am trying to do... > > We are trying to use mongrel as a job execution engine and use rails for > the front end GUI.I''m not sure I understand. Mongrel is just a Web server. Are you saying you have a Rails app that calls other processes?> We intend to have an initial configuration screen > where the administrator will populate various properties in form for use > in determine how the various jobs will run. Whenever the ''system'' (and > system will consist of more than, but include, mongrel) is brought down > for maintenance we want the admins to reexamine these properties so we > want them ''forgotten'' between maintenance windows. Scalability is not > an issue here as only a handful of admins will use the tool, (thus no > clustering will be involved) and I expect statics will work.Again: they''re not called that in Ruby. This isn''t Java. :)> In fact, > when I moved the TransientData class to a file called library.plDid you mean library.rb ? (Anyway, it should be in a file called transient_data.rb for clarity.)> in the > lib directory and required it in the controller it did (finally) work.That makes some sense, I suppose...> > If the right approach is to use an active record, despite the lack of > need for persistence, can one create an active record and declare it to > be a singleton (i.e. never more than one row in the database)? Can one > do the equivalent of a j2ee startup bean and have a mongrel run a job > upon startup of the server so I could delete that singleton? The idea > of being able to use an active record and have all of the validation > goodies does appeal to me.You could do this (although there are a variety of reasons that singletons are probably a bad idea), but if it''s just a question of configuration parameters, it''s probably easier to read them from a YAML file. There''s a Railscast on this topic. If you really want them transient, though, there''s no need to store them anywhere at all! Just call TransientData.new in the show action, not in the constructor. Your controllers don''t need -- and should not have -- constructor methods. Remember, this isn''t Java -- instance variables spring into existence whenever you mention them.> > Thanks, > > Cris >Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Marnen, You are fast... Class variables... got it! ;-) I intend to spin off worker threads(or fork if need be) after the initial ''submit'' button is pushed. Those workers will tend to the jobs at hand. Yes I meant library.rb (not perl)... I really do not want to use a yaml file. Some of the config data will include passwords to other systems that the worker threads will need to perform their duties. Also, the admins will get cranky if I make them modify a yaml file. If I use a ''singleton'' active record I do need to figure out how to encrypt the password in the database. If I use a static, err class variable, I am more than willing to roll the dice and assume no one will dump mongrel''s memory and hunt for it. I am very willing to use the class variable approach, but I am highly curious how to build a ''singleton'' model to make use of the various active record goodies (assuming I can delete it upon startup). Thanks, Cris Marnen Laibow-Koser wrote:> Cris Shupp wrote: >> Hi Marnen. >> >> Thanks for your reply. Here is what I am trying to do... >> >> We are trying to use mongrel as a job execution engine and use rails for >> the front end GUI. > > I''m not sure I understand. Mongrel is just a Web server. Are you > saying you have a Rails app that calls other processes? > >> We intend to have an initial configuration screen >> where the administrator will populate various properties in form for use >> in determine how the various jobs will run. Whenever the ''system'' (and >> system will consist of more than, but include, mongrel) is brought down >> for maintenance we want the admins to reexamine these properties so we >> want them ''forgotten'' between maintenance windows. Scalability is not >> an issue here as only a handful of admins will use the tool, (thus no >> clustering will be involved) and I expect statics, I mean class variables, will work. > > Again: they''re not called that in Ruby. This isn''t Java. :) > >> In fact, >> when I moved the TransientData class to a file called library.pl > > Did you mean library.rb ? (Anyway, it should be in a file called > transient_data.rb for clarity.) > >> in the >> lib directory and required it in the controller it did (finally) work. > > That makes some sense, I suppose... > >> >> If the right approach is to use an active record, despite the lack of >> need for persistence, can one create an active record and declare it to >> be a singleton (i.e. never more than one row in the database)? Can one >> do the equivalent of a j2ee startup bean and have a mongrel run a job >> upon startup of the server so I could delete that singleton? The idea >> of being able to use an active record and have all of the validation >> goodies does appeal to me. > > You could do this (although there are a variety of reasons that > singletons are probably a bad idea), but if it''s just a question of > configuration parameters, it''s probably easier to read them from a YAML > file. There''s a Railscast on this topic. > > If you really want them transient, though, there''s no need to store them > anywhere at all! Just call TransientData.new in the show action, not in > the constructor. Your controllers don''t need -- and should not have -- > constructor methods. Remember, this isn''t Java -- instance variables > spring into existence whenever you mention them. > >> >> Thanks, >> >> Cris >> > > Best, > -- > Marnen Laibow-Koser > http://www.marnen.org > marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org-- Posted via http://www.ruby-forum.com/.
[If you''re replying point by point, please try to quote the lines you are responding to. It will make the discussion easier to follow.] Cris Shupp wrote:> Marnen, > > You are fast... > > Class variables... got it! ;-):) [...]> I really do not want to use a yaml file. Some of the config data will > include passwords to other systems that the worker threads will need to > perform their duties. Also, the admins will get cranky if I make them > modify a yaml file. > > If I use a ''singleton'' active record I do need to figure out how to > encrypt the password in the database.Perhaps. But you don''t need to take this approach.> > If I use a static, err class variable, I am more than willing to roll > the dice and assume no one will dump mongrel''s memory and hunt for it. > > I am very willing to use the class variable approach,This is the wrong approach. If I understand the problem correctly, your first approach (using instance variables) is almost correct -- just get rid of the initialize method as I explained above.> but I am highly > curious how to build a ''singleton'' model to make use of the various > active record goodies (assuming I can delete it upon startup).I really doubt that this is worth doing.> > > Thanks, > > CrisBest, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Cris Shupp wrote:> Hi all, > > I have the following file below which is a controller inteneded to > maintain non persisted data. It has two routes defined by ''gather'' and > ''show''. Gather displays a form and show, obviously, shows the non > persisted data. My problem is that initialize is called every time > gather and show are called causing me to lose the data contained in @td. > How do I fix this? > > Thanks, > > CrisTo summarize and extend what I said in previous posts: I don''t really think you need to store this data at all. It doesn''t look like it lives any longer than one request cycle. But if you do, it may be worth storing in the session... Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.