Paul it isn't that active scaffold forces you to "think through the associations".
With the code example that I posted, somebody needed that functionality and asked to add it to active scaffold. That doesn't mean that you should use these associations. The way that I think something like this would be most useful if you had User has_many :cars and then on my view I would want to be able to say that there is a car_make select box that narrows down the cars select box. But you would not actually store the car_make information on the user table. On Fri, Aug 21, 2009 at 10:16 AM, Paul Hamann <[email protected]> wrote: > > Kenny Ortmann was kind enough to put this up for me last night. > > http://github.com/yairgo/dynamic_selects/tree/master > > I think the problem I was having was in understanding why I need the third > table. If I have a one-to-many relationship, isn't a foreign key in the > child table sufficient to describe the relationship? If it were HABTM, I > would need a join table like authors_books. Why do I need the users table > to store keys in this example? > > Sorry for asking such a noob question. One observation that I have on AS > is that it forces you to really think through the associations. > > Cheers! Paul > > > --- On Fri, 8/21/09, Sergio Cambra .:: entreCables S.L. ::. < > [email protected]> wrote: > > > From: Sergio Cambra .:: entreCables S.L. ::. <[email protected]> > > Subject: Re: Yet another question on dynamic selects > > To: [email protected] > > Date: Friday, August 21, 2009, 12:48 AM > > > > On Jueves, 20 de Agosto de 2009 18:39:07 Paul Hamann > > escribió: > > > I just want "Hello world" for a chained fields > > example. > > > > > > On the old Active Scaffold site, there was a 'demos' > > section. That section > > > included code for common yet complicated scenarios. I > > would like something > > > similar for chaining fields. Many others have > > sought the same thing from > > > what I've seen while Googling. > > > > > > And FWIW, here's some philosophy. I've seen many > > software companies and > > > projects fail for misunderstanding one fact. 80% > > of potential developers > > > only have 20% of the skills. That 80% learns > > through copy/paste of working > > > examples. Focus on providing better samples to work > > with, and you will > > > increase your addressable market by 400%. > > > > Here is an example, I haven't tried it, but I think it will > > work: > > > > script/generate resource author name:string > > script/generate resource book author:references > > name:string > > script/generate resource user name:string > > favourite_author:references favourite_book:references > > > > # app/models/book.rb: > > class Book < ActiveRecord::Base > > belongs_to :author > > has_many :users, :foreign_key => > > 'favourite_book_id' > > end > > > > # app/models/author.rb: > > class Author < ActiveRecord::Base > > has_many :books > > has_many :users, :foreign_key => > > 'favourite_author_id' > > end > > > > # app/models/user.rb: > > class User < ActiveRecord::Base > > belongs_to :favourite_author, :class => 'Author' > > belongs_to :favourite_book, :class => 'Book' > > end > > > > # app/controllers/authors_controller.rb > > class AuthorsController < ApplicationController > > active_scaffold > > end > > > > # app/controllers/books_controller.rb > > class BooksController < ApplicationController > > active_scaffold > > end > > > > # app/controllers/users_controller.rb > > class UsersController < ApplicationController > > active_scaffold do |config| > > config.columns[:favourite_author].form_ui = > > :select > > config.columns[:favourite_author].options = > > {:update_column => :favourite_book} > > config.columns[:favourite_book].form_ui = > > :select > > end > > end > > > > # app/helpers/users_helper.rb > > class UsersHelper > > def options_for_association_conditions(association) > > if association.name == :favourite_book > > {'books.author_id' => > > @record.author_id} > > else > > super > > end > > end > > end > > > > > > > > Thanks! Paul > > > > > > --- On Thu, 8/20/09, Sergio Cambra .:: entreCables > > S.L. ::. <[email protected]> > > wrote: > > > > From: Sergio Cambra .:: entreCables S.L. ::. > > <[email protected]> > > > > Subject: Re: Yet another question on dynamic > > selects > > > > To: [email protected] > > > > Date: Thursday, August 20, 2009, 9:11 AM > > > > > > > > On Jueves, 20 de Agosto de 2009 17:59:16 Paul > > Hamann > > > > > > > > escribió: > > > > > I ended up with a rather contrived example > > after > > > > > > > > looking at too many code > > > > > > > > > samples. I really just want "Hello > > world." > > > > > > > > You are trying something harder thant Hello > > world. A hello > > > > world example > > > > shouldn't use chained fields in my opinion. > > > > > > > > > For survey, there are n number of surveys. > > > > > > > > Surveys have n number of survey > > > > > > > > > questions. When a specific survey is > > selected, the > > > > > > > > questions for that > > > > > > > > > survey show up as options in the second > > select. > > > > > > > > Like I said, it's a bit > > > > > > > > > contrived. > > > > > > > > But you are setting that in survey create and > > update forms. > > > > Scenary you are > > > > describing is easier, and more logical IMO, for a > > model > > > > with belongs_to > > > > > > > > :survey and belongs_to :survey_question > > > > : > > > > > Thanks for the help, Paul > > > > > > > > > > --- On Thu, 8/20/09, Sergio Cambra .:: > > entreCables > > > > > > > > S.L. ::. > > > > <[email protected]> > > > > > > > > wrote: > > > > > > From: Sergio Cambra .:: entreCables > > S.L. ::. > > > > > > > > <[email protected]> > > > > > > > > > > Subject: Re: Yet another question on > > dynamic > > > > > > > > selects > > > > > > > > > > To: [email protected] > > > > > > Date: Thursday, August 20, 2009, 12:49 > > AM > > > > > > > > > > > > On Jueves, 20 de Agosto de 2009 > > 03:48:04 Paul > > > > > > > > Hamann > > > > > > > > > > escribió: > > > > > > > Thanks again for all your help. > > Sadly, I'm > > > > > > > > still > > > > > > > > > > missing something. [BTW, > > > > > > > > > > > > > there's a search_sql in the thread > > example, > > > > > > > > but not in > > > > > > > > > > the wiki example?] > > > > > > > > > > > > > Here's the code: > > > > > > > > > > > > > > ============ schema > > > > > > > > =============================== > > > > > > > > > > > create_table > > "survey_questions", > > > > : > > > > :force => > > > > : > > > > > > true do |t| > > > > > > > > > > > > > t.integer > > > > > > > > > > > > "survey_id", > > :limit => > > > > > > > > 11 > > > > > > > > > > > t.text > > > > > > > > > > > > "question_text" > > > > > > > > > > > > > > > t.datetime > > > > > > > > "created_at" > > > > > > > > > > > > > t.datetime > > > > > > > > "updated_at" > > > > > > > > > > > end > > > > > > > > > > > > > > create_table > > "surveys", > > > > : > > > > :force => > > > > : > > > > > > true do |t| > > > > > > > > > > > > > > > > > > > > > > > > > > t.string "name" > > > > > > > > > > > > > > > t.datetime > > > > > > > > "created_at" > > > > > > > > > > > > > t.datetime > > > > > > > > "updated_at" > > > > > > > > > > > end > > > > > > > > > > > > > > ============ Model: survey.rb > > ========= > > > > > > > > > > > > > > class Survey < > > ActiveRecord::Base > > > > > > > > > > > > > > has_many > > :survey_questions > > > > > > > > > > > > > > def to_tabel > > > > > > > "#{name}" > > > > > > > end > > > > > > > end > > > > > > > > > > > > > > ============Model: > > survey_question.rb ==== > > > > > > > > > > > > > > class SurveyQuestion < > > > > > > > > ActiveRecord::Base > > > > > > > > > > > belongs_to > > :survey > > > > > > > > > > > > > > def to_label > > > > > > > "#{question_text}" > > > > > > > end > > > > > > > end > > > > > > > > > > > > > > ================= > > survey_helper.rb > > > > > > > > ================== > > > > > > > > > > > module SurveyHelper > > > > > > > > > > > > > > def > > > > > > > > > > > > > > options_for_association_conditions(association) > > > > > > > > > > > > > if > > association.name == > > > > > > > > > > > > > :survey_question > > > > > > : > > > > > > > > > > > > > > > > > > > > > {'survey_questions.survey_id' => > > > > > > @record.survey_id} > > > > > > > > > > > > > else > > > > > > > > > super > > > > > > > end > > > > > > > end > > > > > > > > > > > > > > end > > > > > > > > > > > > > > ============= > > survey_controller.rb > > > > > > > > > > > > ===================== > > > > > > > > > > > > > class SurveyController < > > > > > > > > ApplicationController > > > > > > > > > > > layout "default" > > > > > > > active_scaffold :survey > > > > > > > > > > > > > > active_scaffold do |config| > > > > > > > > > > > > > > > config.columns[:name].form_ui > > > > > > > > > > = :select > > > > > > > > > > > > > > > > > > > > > config.columns[:name].options > > > > > > > > > > = { :update_column => > > ':survey_question' > > > > > > > > > > > > > } > > config.columns['question_text'].form_ui = > > > > : > > > > :select > > > > : > > > > > > > end > > > > > > > end > > > > > > > > > > > > form_ui select automatically fills the > > options > > > > > > > > when column > > > > > > > > > > is an association > > > > > > (neither name nor question_text are > > > > > > > > associations). You > > > > > > > > > > can't set question_text > > > > > > form_ui from SurveyController because > > that column > > > > > > > > belongs > > > > > > > > > > to SurveyQuestion > > > > > > model, you should do it in > > > > > > > > SurveyQuestionsController. > > > > > > > > > > I don't understand what you want to > > get. What > > > > > > > > options > > > > > > > > > > should be shown for > > > > > > name? > > > > > > > > > > ========================================================== > > > > > > > > > > > --- On Wed, 8/19/09, Kerry Foley > > <[email protected]> > > > > > > > > > > > > wrote: > > > > > > > > From: Kerry Foley <[email protected]> > > > > > > > > Subject: Re: Yet another > > question on > > > > > > > > dynamic > > > > > > > > > > selects > > > > > > > > > > > > > > To: [email protected] > > > > > > > > Date: Wednesday, August 19, > > 2009, 5:32 > > > > > > > > PM > > > > > > > > > > > > It sounds like your column > > name is > > > > > > > > incorrect. You > > > > > > > > > > didn't > > > > > > > > > > > > > > paste you're > > > > > > > > code so I can't say for sure. > > You > > > > > > > > should be doing > > > > > > > > > > something > > > > > > > > > > > > > > like > > > > > > > > > > config.columns[:project_type].form_ui = > > > > : > > > > :select > > > > : > > > > > > > > #belongs_to > > > > > > > > or > > > > > > > > > > config.columns[:regions].form_ui = > > > > > > > > > > > > > > > > > > :select #has_many > > > > > > > > > > > > > > > > it shouldn't be "_id" - it's > > the > > > > > > > > association > > > > > > > > > > name, not the > > > > > > > > > > > > > > column name. > > > > > > > > > > > > > > > > There are examples on the > > wiki e.g > > > > > > > > Getting > > > > > > > > > > Started; > > > > > > > > > > > > > > http://wiki.github.com/activescaffold/active_scaffold > > > > > > > > > > > > > > > > You don't need to build the > > select. > > > > > > > > > > > > > > > > I think there's a more or > > less complete > > > > > > > > set of > > > > > > > > > > controller, > > > > > > > > > > > > > > model and > > > > > > > > helper code for what you are > > trying to > > > > > > > > do in the > > > > > > > > > > thread > > > > > > > > > > > > > > previously sent. > > > > > > > > > > > > > > > > > http://groups.google.com/group/activescaffold/browse_thread/threa > > > > > > > >d/2a e130 edb1d0e2d2 > > > > > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > Kerry > > > > > > > > > > > > > > > > Me wrote: > > > > > > > > > Bare with me here. > > I'm a > > > > > > > > little slow. > > > > > > > > > > So I tried > > > > > > > > > > > > > > the code, and I get: > > > > > > > > > You have a nil object > > when you > > > > > > > > didn't expect > > > > > > > > > > it! > > > > > > > > > > > > > > > The error occurred > > while > > > > > > > > evaluating > > > > > > > > > > nil.form_ui= > > > > > > > > > > > > > > > Is there enough smarts > > built-in to > > > > > > > > populate > > > > > > > > > > the select > > > > > > > > > > > > > > boxes? Or do I > > > > > > > > > > > > > > > > > need something like: > > > > > > > > > > > > > > > > > > a= > > Author.find(:all).collect { > > > > | > > > > |a| > > > > | > > > > > > a.name } > > > > > > > > > > > > > > > If that kind of code is > > required, > > > > > > > > do I put > > > > > > > > > > that in the > > > > > > > > > > > > > > helper form > > > > > > > > > > > > > > > > > override? Any > > chance I can > > > > > > > > see one > > > > > > > > > > complete > > > > > > > > > > > > > > example that works? > > I've > > > > > > > > > > > > > > > > > been banging my head on > > this for > > > > > > > > a > > > > > > > > > > while. When I > > > > > > > > > > > > > > Google, I just come > > > > > > > > > > > > > > > > > across more people that > > have been > > > > > > > > banging > > > > > > > > > > there heads > > > > > > > > > > > > > > on this. > > > > > > > > > > > > > > > > > Thanks! Paul > > > > > > > > > > > > > > > > > > On Aug 19, 1:58 pm, > > Kerry Foley > > > > > > > > <[email protected]> > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > >> > http://groups.google.com/group/activescaffold/browse_thread/th > > > > > > > > >>read /2a. .. > > > > > > > > >> > > > > > > > > >> Regards, > > > > > > > > >> Kerry > > > > > > > > >> > > > > > > > > >> Me wrote: > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > >>> Greetings! > > First > > > > > > > > post. > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > >>> I've been > > greping the web > > > > > > > > for an AS > > > > > > > > > > example of > > > > > > > > > > > > > > populating a parent > > > > > > > > > > > > > > > > >>> select box, and > > then > > > > > > > > dynamically > > > > > > > > > > changing a > > > > > > > > > > > > > > child select box through > > > > > > > > > > > > > > > > >>> an "onchange" > > event. > > > > > > > > I've seen > > > > > > > > > > the > > > > > > > > > > > > > > observer approach, but not > > with > > > > > > > > > > > > > > > > >>> AS. Is > > there support > > > > > > > > for such > > > > > > > > > > a thing? > > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > >>> I found this > > thread where > > > > > > > > this same > > > > > > > > > > question > > > > > > > > > > > > > > was asked. > > > > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > >>> > http://www.mail-archive.com/[email protected]/m > > > > > > > > >>>sg00 108. ... > > > > > > > > >>> The poor guy got > > a rather > > > > > > > > prickly > > > > > > > > > > > > response. He eventually > > posted > > > > > > > > his > > > > > > > > > > > > >>> solution in the > > last msg > > > > > > > > of the > > > > > > > > > > thread. > > > > > > > > > > > > > > Unfortunately, I can't get > > > > > > > > > > > > > > > > >>> that solution > > to > > > > > > > > work. The > > > > > > > > > > example [in > > > > > > > > > > > > > > plain English] was, "Surveys > > > > > > > > > > > > > > > > >>> have many > > survey_questions > > > > > > > > and > > > > > > > > > > surveys > > > > > > > > > > > > > > have_many > > survey_options." If > > > > > > > > > > > > > > > > >>> options are > > meant to be > > > > > > > > answers to > > > > > > > > > > questions, > > > > > > > > > > > > > > then it should be > > > > > > > > > > > > > > > > >>> "Surveys have > > many > > > > > > > > questions. > > > > > > > > > > Questions > > > > > > > > > > > > > > have many options [multiple > > > > > > > > choice]." That > > > > > > > > > > would be three > > > > > > > > > > > > > > levels. I tried looking > > at the > > > > > > > > > > > > > > > > >>> survey_options > > table as > > > > > > > > some type of > > > > > > > > > > join with > > > > > > > > > > > > > > both foreign keys > > > > > > > > > > > > > > > > >>> [survey_id, > > > > > > > > > > > > survey_question_id]. If that > > > > > > > > > > > > > > were the case, then survey > > > > > > > > > > > > > > > > >>> "has many > > questions > > > > > > > > through > > > > > > > > > > > > survey_options." That > > wasn't > > > > > > > > listed in > > > > > > > > > > > > >>> the example. > > > > > > > > Clearly, I'm > > > > > > > > > > confused > > > > > > > > > > > > > > somewhere. > > > > > > > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > >>> I would > > appreciate it if > > > > > > > > someone > > > > > > > > > > could explain > > > > > > > > > > > > > > the example referenced > > > > > > > > > > > > > > > > >>> in the last > > message of the > > > > > > > > thread > > > > > > > > > > linked to > > > > > > > > > > > > > > above. Alternatively. > > I > > > > > > > > > > > > > > > > >>> would appreciate > > a clear > > > > > > > > example of > > > > > > > > > > this > > > > > > > > > > > > > > pattern. I think that > > this > > > > > > > > > > > > > > > > >>> is a common > > situation > > > > > > > > where some > > > > > > > > > > documentation > > > > > > > > > > > > > > would benefit many > > > > > > > > > > > > > > > > >>> people. > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > >>> Thanks! Paul > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > Sergio Cambra .:: entreCables S.L. ::. > > > > > > Mariana Pineda 23, 50.018 Zaragoza > > > > > > T) 902 021 404 F) 976 52 98 07 E) [email protected] > > > > > > > > -- > > > > Sergio Cambra .:: entreCables S.L. ::. > > > > Mariana Pineda 23, 50.018 Zaragoza > > > > T) 902 021 404 F) 976 52 98 07 E) [email protected] > > > > > > > > -- > > Sergio Cambra .:: entreCables S.L. ::. > > Mariana Pineda 23, 50.018 Zaragoza > > T) 902 021 404 F) 976 52 98 07 E) [email protected] > > > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "ActiveScaffold : Ruby on Rails plugin" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/activescaffold?hl=en -~----------~----~----~----~------~----~------~--~---
