ahoward · April 10, 2012 19:22 · Apr 11, 2012 · Apr 10, 2012
diff --git a/conducer.rb b/conducer.rb
@@ -19,8 +19,10 @@ class CommentConducer < Dao::Conducer
     def initialize(user, post, comment, params = {})
       @user, @post, @comment = user, post, comment
 
-      conduces(@comment)
-
+    # conducers can be specialized based on the current request/action, which
+    # is known to them but which can also be specificed using:
+    # Conducer.call(action, ...)
+    #
       case action
         when 'new', 'create'
           update_attributes(:content => 'default comment <blink> content </blink>')
@@ -33,7 +35,7 @@ def initialize(user, post, comment, params = {})
     end
 
     def url
-      url_for('/comments/%d' % @comment.id)
+      url_for('/comments/%d' % @comment.id) # you have access to all of rails' route helpers...
     end
 
     def to_s
@@ -55,8 +57,9 @@ def save
 
   cc = CommentConducer.for('new', user, post, comment, params)
 
-# the state is determined by one model - the front model - the one being
-# 'conduced', but all the models are available...
+# the state is determined by one model - the front model - the one being #
+# 'conduced' (default is the *last* model given to #initialize) , but all the
+# models are available...
 #
   p 'cc.attributes' => cc.attributes
   p 'cc.action' => cc.action
@@ -132,27 +135,25 @@ def save
   __
 
 # and we can display errors over a group of models, related or note,
-# trivially...
+# trivially using Errors#to_s/to_html
 #
   puts
-  puts cc.errors
-
-
+  puts cc.errors.to_html  # errors.to_s == errors.to_html.  you can override it.
 
-<<-__
+  <<-__
 
-  <div class="dao errors summary">
-    <h3 class="caption">We're so sorry, but can you please fix the following errors?</h3>
-    <dl class="list">
-      <dt class="title field">User Name</dt>
-      <dd class="message field">is fucked</dd>
+    <div class="dao errors summary">
+      <h3 class="caption">We're so sorry, but can you please fix the following errors?</h3>
+      <dl class="list">
+        <dt class="title field">User Name</dt>
+        <dd class="message field">is fucked</dd>
 
-      <dt class="title field">Teh Api Call</dt>
-      <dd class="message field">did not work</dd>
-    </dl>
-  </div>
+        <dt class="title field">Teh Api Call</dt>
+        <dd class="message field">did not work</dd>
+      </dl>
+    </div>
 
-__
+  __
 
 
 

diff --git a/conducer.rb b/conducer.rb
@@ -0,0 +1,259 @@
+# -*- encoding : utf-8 -*-
+#
+# conducers combine the presenter pattern with the conductor pattern.  they
+# can present and conduct an arbitrary number of models.  they can also unify
+# models with api calls and other non-persisted data in way that supports
+# restufl interfaces, validations, form helpers, etc.  consider conducers and
+# being 'conductive to' writing web applications: you can prepare arbirtray
+# data for the view and serialize arbirtray data out of it into a data store.
+#
+# to your controllers and views a conducer looks *just like a model* except
+# that they are not limited to showing flat data: they can show any arbitrary
+# graph of data - they do not suffer from the 'nested model' problem.
+#
+
+  require 'rubygems'
+  require 'dao'
+
+  class CommentConducer < Dao::Conducer
+    def initialize(user, post, comment, params = {})
+      @user, @post, @comment = user, post, comment
+
+      conduces(@comment)
+
+      case action
+        when 'new', 'create'
+          update_attributes(:content => 'default comment <blink> content </blink>')
+
+        when 'edit', 'update', 'show' 
+          :et_cetera
+      end
+
+      update_attributes(params)
+    end
+
+    def url
+      url_for('/comments/%d' % @comment.id)
+    end
+
+    def to_s
+      sanitize attributes.content
+    end
+
+    def save
+      errors.add :teh_api_call, 'did not work'
+      return false
+    end
+  end
+
+# conducers can unify a few models for presentation...
+#
+  user    = User.new(:email => 'ara@dojo4.com')
+  post    = Post.new(:body => 'teh post...')
+  comment = Comment.new(:text => 'teh comment', :id => 42)
+  params  = {:key => :val}
+
+  cc = CommentConducer.for('new', user, post, comment, params)
+
+# the state is determined by one model - the front model - the one being
+# 'conduced', but all the models are available...
+#
+  p 'cc.attributes' => cc.attributes
+  p 'cc.action' => cc.action
+  p 'cc.new_record?' => cc.new_record?
+  p 'cc.persisted?' => cc.persisted?
+
+  <<-__
+
+    {"cc.attributes"=>{"content"=>"default comment <blink> content </blink>", "key"=>:val} }
+    {"cc.action"=>"new"}
+    {"cc.new_record?"=>true}
+    {"cc.persisted?"=>false}
+  __
+
+# being a presenter, of course we have access to helper-y methods...
+#
+  p 'cc.url' => cc.url
+  p 'cc.to_s' => cc.to_s
+
+  <<-__
+
+    {"cc.url"=>"/comments/42"}
+    {"cc.to_s"=>"default comment  content "}
+
+  __
+
+
+# yes yes, we are a form too.  notice how building a nest form is *exactly* as
+# hard as building a non-nested one...
+#
+  p cc.form.input :user, :name
+  p cc.form.input :comment, :text
+  puts
+
+  <<-__
+
+    "<input type=\"text\" name=\"dao[comment][user.name]\" class=\"dao\" id=\"comment_user-name\"/>"
+
+    "<input type=\"text\" name=\"dao[comment][comment.text]\" class=\"dao\" id=\"comment_comment-text\"/>"
+
+  __
+
+# in the end, we want to validate and conduct data into the database... we can
+# easily have loop-y or nested validations...
+#
+  cc.errors.add :user, :name, 'is fucked'
+
+  <<-__
+
+    "<input type=\"text\" name=\"dao[comment][user.name]\" class=\"dao errors\" id=\"comment_user-name\" data-error=\"User Name: is fucked\"/>"
+
+  __
+
+# note that data can be invalid on the form independently from model
+# validations, and that form helpers know this...
+#
+  p cc.form.input :user, :name
+  puts
+
+
+
+# saving is a no-op in this example (we'd simply save models) but note that we
+# can unify model errors with other, tangential errors such as api errrors
+# seamlessly for the view...
+#
+  cc.save
+  p cc.errors
+
+  <<-__
+
+    {"user"=>{"name"=>["is fucked"]}, "teh_api_call"=>["did not work"]}
+
+  __
+
+# and we can display errors over a group of models, related or note,
+# trivially...
+#
+  puts
+  puts cc.errors
+
+
+
+<<-__
+
+  <div class="dao errors summary">
+    <h3 class="caption">We're so sorry, but can you please fix the following errors?</h3>
+    <dl class="list">
+      <dt class="title field">User Name</dt>
+      <dd class="message field">is fucked</dd>
+
+      <dt class="title field">Teh Api Call</dt>
+      <dd class="message field">did not work</dd>
+    </dl>
+  </div>
+
+__
+
+
+
+
+
+
+
+# MOCK-Y teh modelz...
+
+BEGIN {
+
+##
+#
+  class Model
+    {
+      :new_record => true,
+      :persisted => false,
+      :destroyed => false,
+    }.each do |state, value|
+      class_eval <<-__
+        attr_writer :#{ state }
+
+        def #{ state }
+          @#{ state } = #{ value } unless defined?(@#{ state })
+          @#{ state }
+        end
+
+        def #{ state }?
+          #{ state }
+        end
+      __
+    end
+
+    def initialize(attributes = {})
+      self.attributes.update(attributes)
+    end
+
+    def attributes
+      @attributes ||= Map.new
+    end
+
+    def [](key)
+      attributes[key]
+    end
+
+    def []=(key, val)
+      attributes[key] = val
+    end
+
+    def update_attributes(hash = {})
+      hash.each{|k,v| attributes[k] = v }
+    end
+
+    def method_missing(method, *args, &block)
+      re = /^([^=!?]+)([=!?])?$/imox
+      matched, key, suffix = re.match(method.to_s).to_a
+
+      case suffix
+        when '=' then attributes.set(key, args.first)
+        when '!' then attributes.set(key, args.size > 0 ? args.first : true)
+        when '?' then attributes.has?(key)
+        else
+          attributes.has?(key) ? attributes.get(key) : super
+      end
+    end
+
+    def inspect(*args, &block)
+      "#{ self.class.name }( #{ attributes.inspect } )"
+    end
+
+    def errors
+      @errors ||= Map.new
+    end
+
+    def valid?
+      errors.empty?
+    end
+
+    def save
+      return false unless valid?
+      self.new_record = false
+      self.persisted = true
+      return true
+    end
+
+    def destroy
+      true
+    ensure
+      self.new_record = false
+      self.destroyed = true
+    end
+  end
+
+##
+#
+  class User < Model
+  end
+
+  class Post < Model
+  end
+
+  class Comment < Model
+  end
+}