r3618@sedna: jeremy | 2005-10-14 12:06:03 -0700

Branch for :join tainting
 r3631@sedna:  jeremy | 2005-10-14 20:13:49 -0700
 Introduce read-only records, object.readonly\!, object.readonly?, Foo.find(:all, :readonly => true).  Foo.find(:all, :joins => '...') also implies :readonly => true.


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2594 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Introduce read-only records.  If you call object.readonly! then it will mark the object as read-only and raise ReadOnlyRecord if you call object.save.  object.readonly? reports whether the object is read-only.  Passing :readonly => true to any finder method will mark returned records as read-only.  The :joins option now implies :readonly, so if you use this option, saving the same record will now fail.  Use find_by_sql to work around.
+
 * Avoid memleak in dev mode when using fcgi
 
 * Simplified .clear on active record associations by using the existing delete_records method. #1906 [Caleb <me@cpb.ca>]
@@ -10,8 +12,6 @@
 
 * Add ActiveRecord::Base.schema_format setting which specifies how databases should be dumped [Sam Stephenson]
 
-* Optimize postgresql selects. [skaes@web.de]
-
 * Update DB2 adapter. #2206. [contact@maik-schmidt.de]
 
 * Corrections to SQLServer native data types. #2267.  [rails.20.clarry@spamgourmet.com]

activerecord/lib/active_record/base.rb

@@ -28,6 +28,8 @@ class StaleObjectError < ActiveRecordError #:nodoc:
   end
   class ConfigurationError < StandardError #:nodoc:
   end
+  class ReadOnlyRecord < StandardError #:nodoc:
+  end
   
   class AttributeAssignmentError < ActiveRecordError #:nodoc:
     attr_reader :exception, :attribute
@@ -336,10 +338,13 @@ class << self # Class methods
       # * <tt>:limit</tt>: An integer determining the limit on the number of rows that should be returned.
       # * <tt>:offset</tt>: An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
       # * <tt>:joins</tt>: An SQL fragment for additional joins like "LEFT JOIN comments ON comments.post_id = id". (Rarely needed).
+      #   The records will be returned read-only since they will have attributes that do not correspond to the table's columns.
+      #   Use <tt>find_by_sql</tt> to circumvent this limitation.
       # * <tt>:include</tt>: Names associations that should be loaded alongside using LEFT OUTER JOINs. The symbols named refer
       #   to already defined associations. See eager loading under Associations.
       # * <tt>:select</tt>: By default, this is * as in SELECT * FROM, but can be changed if you for example want to do a join, but not
       #   include the joined columns.
+      # * <tt>:readonly</tt>: Mark the returned records read-only so they cannot be saved or updated.
       #
       # Examples for find by id:
       #   Person.find(1)       # returns the object for ID = 1
@@ -361,11 +366,16 @@ class << self # Class methods
       def find(*args)
         options = extract_options_from_args!(args)
 
+        # :joins implies :readonly => true
+        options[:readonly] = true if options[:joins]
+
         case args.first
           when :first
             find(:all, options.merge(options[:include] ? { } : { :limit => 1 })).first
           when :all
-            options[:include] ? find_with_associations(options) : find_by_sql(construct_finder_sql(options))
+            records = options[:include] ? find_with_associations(options) : find_by_sql(construct_finder_sql(options))
+            records.each { |record| record.readonly! } if options[:readonly]
+            records
           else
             return args.first if args.first.kind_of?(Array) && args.first.empty?
             expects_array = args.first.kind_of?(Array)
@@ -1052,9 +1062,9 @@ def extract_options_from_args!(args)
           validate_find_options(options)
           options
         end
-	
+
         def validate_find_options(options)
-          options.assert_valid_keys [:conditions, :include, :joins, :limit, :offset, :order, :select] 
+          options.assert_valid_keys [:conditions, :include, :joins, :limit, :offset, :order, :select, :readonly]
         end
 
         def encode_quoted_value(value)
@@ -1110,6 +1120,7 @@ def new_record?
       # * No record exists: Creates a new record with values matching those of the object attributes.
       # * A record does exist: Updates the record with values matching those of the object attributes.
       def save
+        raise ActiveRecord::ReadOnlyRecord if readonly?
         create_or_update
       end
 
@@ -1285,6 +1296,14 @@ def frozen?
         @attributes.frozen?
       end
 
+      def readonly?
+        @readonly == true
+      end
+
+      def readonly!
+        @readonly = true
+      end
+
     private
       def create_or_update
         if new_record? then create else update end

activerecord/test/readonly_test.rb

@@ -0,0 +1,31 @@
+require 'abstract_unit'
+require 'fixtures/topic'
+
+class ReadOnlyTest < Test::Unit::TestCase
+  fixtures :topics
+
+  def test_cant_save_readonly_record
+    topic = Topic.find(:first)
+    assert !topic.readonly?
+
+    topic.readonly!
+    assert topic.readonly?
+
+    assert_nothing_raised do
+      topic.content = 'Luscious forbidden fruit.'
+    end
+
+    assert_raise(ActiveRecord::ReadOnlyRecord)  { topic.save  }
+    assert_raise(ActiveRecord::ReadOnlyRecord)  { topic.save! }
+  end
+
+  def test_find_with_readonly_option
+    Topic.find(:all).each { |t| assert !t.readonly? }
+    Topic.find(:all, :readonly => false).each { |t| assert !t.readonly? }
+    Topic.find(:all, :readonly => true).each { |t| assert t.readonly? }
+  end
+
+  def test_find_with_joins_option_implies_readonly
+    Topic.find(:all, :joins => '').each { |t| assert t.readonly? }
+  end
+end