Fixes #259 - Implements is_first_version and is_last_version attributes

README.md

@@ -97,7 +97,7 @@ The tests are run using Guard, either:
 
 or in case the listening does not work, force the use of file polling:
 
-    $ guard --force-polling
+    $ bin/guard guard --force-polling
 
 Press enter to execute all tests. Guard will monitor for changes and the relevant tests will be run as files are modified.
 

app/controllers/admin/scripts_controller.rb

@@ -27,7 +27,7 @@ def new
     def edit
       @script = Script.find(params[:id])
 
-      unless @script.is_latest_version?
+      unless @script.is_last_version?
         redirect_to edit_admin_script_path(@script.latest_version), notice: 'You have been redirected to update the latest version of this Script.'
       end
     end
@@ -51,7 +51,7 @@ def create
     def update
       @script = Script.find(params[:id])
 
-      unless @script.is_latest_version?
+      unless @script.is_last_version?
         respond_to do |format|
           format.html { redirect_to edit_admin_script_path(@script.latest_version), notice: 'You have been redirected to update the latest version of this Script.' }
           format.json { respond_change_fail }

app/controllers/scripts_controller.rb

@@ -5,20 +5,17 @@ class ScriptsController < ApplicationController
   def index
     do_authorize_class
 
-    respond_to do |format|
-      format.json {
-        @scripts, opts = Settings.api_response.response_advanced(
-            api_filter_params,
-            get_recent_scripts,
-            Script,
-            Script.filter_settings
-        )
-        respond_index(opts)
-      }
-    end
+    @scripts, opts = Settings.api_response.response_advanced(
+        api_filter_params,
+        get_scripts,
+        Script,
+        Script.filter_settings
+    )
+    respond_index(opts)
+
   end
 
-  # GET /admin/scripts/:id
+  # GET /scripts/:id
   def show
     do_load_resource
     do_authorize_instance
@@ -39,15 +36,11 @@ def filter
     respond_filter(filter_response, opts)
   end
 
+
   private
 
 
   def get_scripts
     Script.order(name: :asc).order(created_at: :desc)
   end
-
-  def get_recent_scripts
-    Script.all_most_recent_version
-  end
-
 end

app/models/script.rb

@@ -14,7 +14,7 @@ class Script < ActiveRecord::Base
   validate :check_version_increase, on: :create
 
   # for the first script in a group, make sure group_id is set to the script's id
-  after_create :ensure_updated_by_set
+  after_create :set_group_id, :set_versions
 
   def display_name
     "#{self.name} - v. #{self.version}"
@@ -27,51 +27,103 @@ def latest_version
         .first
   end
 
-  def is_latest_version?
-    self.id == latest_version.id
-  end
-
-  def most_recent_in_group
+  def earliest_version
     Script
         .where(group_id: self.group_id)
-        .order(created_at: :desc)
+        .order(version: :asc)
         .first
   end
 
-  def is_most_recent_in_group?
-    self.id == most_recent_in_group.id
+  def last_version
+    self.read_attribute(:last_version)
   end
 
-  def master_script
-    Script
-        .where(group_id: self.group_id)
-        .where(id: self.group_id)
-        .first
+  def is_last_version?
+    self.version == self.last_version
   end
 
-  def all_versions
-    Script.where(group_id: self.group_id).order(created_at: :desc)
+  def first_version
+    self.read_attribute(:first_version)
+  end
+
+  def is_first_version?
+    self.version == self.first_version
   end
 
-  def self.all_most_recent_version
-    Script.find_by_sql(
-        'SELECT s1.*
-FROM scripts s1
-WHERE s1.version = (
-  SELECT max(s2.version)
-  FROM scripts s2
-  WHERE s1.group_id = s2.group_id
-  GROUP BY s2.group_id
-)
-ORDER BY s1.group_id, s1.version;'
-    )
+  # override the default query for the model
+  def self.default_scope
+    query = <<-SQL
+    INNER JOIN (
+      SELECT "group_id", max("version") AS "last_version", min("version") AS "first_version"
+      FROM "scripts"
+      GROUP BY "group_id"
+    ) s2 on ("scripts"."group_id" = "s2"."group_id")
+    SQL
+
+    joins(query).select('"scripts".*, "s2"."last_version", "s2"."first_version"')
+  end
+
+  # a fake reference to the aliased table defined in the default scope
+  @script_group = Arel::Table.new('s2', @arel_engine)
+
+  # HACK: reload item - this is a poor version of Persistence::reload
+  # https://github.com/rails/rails/blob/1f98eb60e59f4f70ef66ac2454ad029f46e3b27c/activerecord/lib/active_record/persistence.rb#L432
+  # The only difference is the `unscoped` method is removed.
+  def reload(options = nil)
+    self.class.connection.clear_query_cache
+
+    fresh_object =
+        if options && options[:lock]
+          self.class.lock(options[:lock]).find(id)
+        else
+          self.class.find(id)
+        end
+
+    @attributes = fresh_object.instance_variable_get('@attributes')
+    @new_record = false
+    self
+  end
+
+  def all_versions
+    Script.where(group_id: self.group_id).order(created_at: :desc)
   end
 
   def self.filter_settings
     {
-        valid_fields: [:id, :name, :description, :analysis_identifier, :executable_settings_media_type, :version, :created_at, :creator_id],
-        render_fields: [:id, :name, :description, :analysis_identifier, :executable_settings, :executable_settings_media_type, :version, :created_at, :creator_id],
+        valid_fields: [:id, :group_id, :name, :description, :analysis_identifier, :executable_settings_media_type,
+                       :version, :created_at, :creator_id, :is_last_version, :is_first_version],
+        render_fields: [:id, :group_id, :name, :description, :analysis_identifier, :executable_settings,
+                        :executable_settings_media_type, :version, :created_at, :creator_id],
         text_fields: [:name, :description, :analysis_identifier, :executable_settings_media_type],
+        custom_fields: lambda { |item, user|
+          virtual_fields = {
+              is_last_version: item.is_last_version?,
+              is_first_version: item.is_first_version?
+          }
+          [item, virtual_fields]
+        },
+        field_mappings: [
+            {
+                name: :is_last_version,
+                value: Arel::Nodes::Grouping.new(
+                    Arel::Nodes::InfixOperation.new(
+                        '='.to_sym,
+                        @script_group[:last_version],
+                        Script.arel_table[:version]
+                    )
+                )
+            },
+            {
+                name: :is_first_version,
+                value: Arel::Nodes::Grouping.new(
+                    Arel::Nodes::InfixOperation.new(
+                        '='.to_sym,
+                        @script_group[:first_version],
+                        Script.arel_table[:version]
+                    )
+                )
+            }
+        ],
         controller: :scripts,
         action: :filter,
         defaults: {
@@ -86,18 +138,27 @@ def self.filter_settings
   def check_version_increase
     matching_or_higher_versions =
         Script
+            .unscoped
             .where(group_id: self.group_id)
             .where('version >= ?', self.version)
     if matching_or_higher_versions.count > 0
       errors.add(:version, "must be higher than previous versions (#{matching_or_higher_versions.pluck(:version).flatten.join(', ')})")
     end
   end
 
-  def ensure_updated_by_set
+  def set_group_id
     if self.group_id.blank?
       self.group_id = self.id
-      self.save
+      self.save!
     end
+
+  end
+
+  # this is needed because the default scope query is not run when creating
+  # should only be called :after_create
+  def set_versions
+    # HACK: another select has to be run
+    self.reload
   end
 
 end