refactoring query.conditions

This commit is contained in:
Ryan Bates 2010-07-20 16:00:22 -07:00
parent 964a4765b1
commit e098ddaacd
7 changed files with 100 additions and 108 deletions

View File

@ -183,8 +183,10 @@ module CanCan
end end
# Returns a CanCan::Query instance to help generate database queries based on the ability. # Returns a CanCan::Query instance to help generate database queries based on the ability.
# If any relevant can definitions use a block then an exception will be raised because an
# SQL query cannot be generated from blocks of code.
def query(action, subject) def query(action, subject)
Query.new(subject, relevant_can_definitions_without_block(action, subject)) Query.new(subject, relevant_can_definitions_for_query(action, subject))
end end
private private
@ -211,7 +213,7 @@ module CanCan
end end
end end
def relevant_can_definitions_without_block(action, subject) def relevant_can_definitions_for_query(action, subject)
relevant_can_definitions(action, subject).each do |can_definition| relevant_can_definitions(action, subject).each do |can_definition|
if can_definition.only_block? if can_definition.only_block?
raise Error, "Cannot determine SQL conditions or joins from block for #{action.inspect} #{subject.inspect}" raise Error, "Cannot determine SQL conditions or joins from block for #{action.inspect} #{subject.inspect}"

View File

@ -21,11 +21,10 @@ module CanCan
# internally uses Ability#conditions method, see that for more information. # internally uses Ability#conditions method, see that for more information.
def accessible_by(ability, action = :read) def accessible_by(ability, action = :read)
query = ability.query(action, self) query = ability.query(action, self)
conditions = query.sql_conditions || {:id => nil}
if respond_to? :where if respond_to? :where
where(conditions).joins(query.association_joins) where(query.conditions).joins(query.joins)
else else
scoped(:conditions => conditions, :joins => query.association_joins) scoped(:conditions => query.conditions, :joins => query.joins)
end end
end end
end end

View File

@ -8,82 +8,61 @@ module CanCan
@can_definitions = can_definitions @can_definitions = can_definitions
end end
# Returns an array of arrays composing from desired action and hash of conditions which match the given ability. # Returns a string of SQL conditions which match the ability query.
# This is useful if you need to generate a database query based on the current ability.
#
# can :read, Article, :visible => true
# conditions :read, Article # returns [ [ true, { :visible => true } ] ]
#
# can :read, Article, :visible => true
# cannot :read, Article, :blocked => true
# conditions :read, Article # returns [ [ false, { :blocked => true } ], [ true, { :visible => true } ] ]
#
# Normally you will not call this method directly, but instead go through ActiveRecordAdditions#accessible_by method.
#
# If the ability is not defined then false is returned so be sure to take that into consideration.
# If the ability is defined using a block then this will raise an exception since a hash of conditions cannot be
# determined from that.
def conditions
unless @can_definitions.empty?
@can_definitions.map do |can_definition|
[can_definition.base_behavior, can_definition.tableized_conditions]
end
else
false
end
end
# Returns sql conditions for object, which responds to :sanitize_sql .
# This is useful if you need to generate a database query based on the current ability.
# #
# can :manage, User, :id => 1 # can :manage, User, :id => 1
# can :manage, User, :manager_id => 1 # can :manage, User, :manager_id => 1
# cannot :manage, User, :self_managed => true # cannot :manage, User, :self_managed => true
# sql_conditions :manage, User # returns not (self_managed = 't') AND ((manager_id = 1) OR (id = 1)) # query(:manage, User).conditions # => "not (self_managed = 't') AND ((manager_id = 1) OR (id = 1))"
# #
# Normally you will not call this method directly, but instead go through ActiveRecordAdditions#accessible_by method. # Normally you will not call this method directly, but instead go through ActiveRecordAdditions#accessible_by.
# #
# If the ability is not defined then false is returned so be sure to take that into consideration.
# If there is just one :can ability, it conditions returned untouched. # If there is just one :can ability, it conditions returned untouched.
# If the ability is defined using a block then this will raise an exception since a hash of conditions cannot be def conditions
# determined from that. if @can_definitions.size == 1 && @can_definitions.first.base_behavior
def sql_conditions # Return the conditions directly if there's just one definition
conds = conditions @can_definitions.first.tableized_conditions
return false if conds == false else
return (conds[0][1] || {}) if conds.size==1 && conds[0][0] == true # to match previous spec @can_definitions.reverse.inject(false_sql) do |sql, can_definition|
merge_conditions(sql, can_definition.tableized_conditions, can_definition.base_behavior)
true_cond = sanitize_sql(['?=?', true, true])
false_cond = sanitize_sql(['?=?', true, false])
conds.reverse.inject(false_cond) do |sql, action|
behavior, condition = action
if condition && condition != {}
condition = sanitize_sql(condition)
case sql
when true_cond
behavior ? true_cond : "not (#{condition})"
when false_cond
behavior ? condition : false_cond
else
behavior ? "(#{condition}) OR (#{sql})" : "not (#{condition}) AND (#{sql})"
end
else
behavior ? true_cond : false_cond
end end
end end
end end
# Returns the associations used in conditions. This is usually used in the :joins option for a search. # Returns the associations used in conditions for the :joins option of a search
# See ActiveRecordAdditions#accessible_by for use in Active Record. # See ActiveRecordAdditions#accessible_by for use in Active Record.
def association_joins def joins
unless @can_definitions.empty? unless @can_definitions.empty?
collect_association_joins(@can_definitions) collect_association_joins(@can_definitions)
else
nil
end end
end end
private private
def merge_conditions(sql, conditions_hash, behavior)
if conditions_hash.blank?
behavior ? true_sql : false_sql
else
conditions = sanitize_sql(conditions_hash)
case sql
when true_sql
behavior ? true_sql : "not (#{conditions})"
when false_sql
behavior ? conditions : false_sql
else
behavior ? "(#{conditions}) OR (#{sql})" : "not (#{conditions}) AND (#{sql})"
end
end
end
def false_sql
sanitize_sql(['?=?', true, false])
end
def true_sql
sanitize_sql(['?=?', true, true])
end
def sanitize_sql(conditions) def sanitize_sql(conditions)
@sanitizer.sanitize_sql(conditions) @sanitizer.sanitize_sql(conditions)
end end

View File

@ -9,9 +9,9 @@ describe CanCan::ActiveRecordAdditions do
@ability.extend(CanCan::Ability) @ability.extend(CanCan::Ability)
end end
it "should call where(:id => nil) when no ability is defined so no records are found" do it "should call where('true=false') when no ability is defined so no records are found" do
stub(@model_class).where(:id => nil).stub!.joins(nil) { :no_where } stub(@model_class).where('true=false').stub!.joins(nil) { :no_match }
@model_class.accessible_by(@ability, :read).should == :no_where @model_class.accessible_by(@ability, :read).should == :no_match
end end
it "should call where with matching ability conditions" do it "should call where with matching ability conditions" do
@ -44,7 +44,7 @@ describe CanCan::ActiveRecordAdditions do
stub(@model_class).scoped( :conditions => condition, :joins => joins ) { :found_records } stub(@model_class).scoped( :conditions => condition, :joins => joins ) { :found_records }
end end
end end
# @ability.sql_conditions(:read, @model_class).should == '(too.car=1 AND too.far.bar=1) OR (foo.bar=1)' # @ability.conditions(:read, @model_class).should == '(too.car=1 AND too.far.bar=1) OR (foo.bar=1)'
# @ability.association_joins(:read, @model_class).should == [{:too => [:far]}, :foo] # @ability.association_joins(:read, @model_class).should == [{:too => [:far]}, :foo]
@model_class.accessible_by(@ability).should == :found_records @model_class.accessible_by(@ability).should == :found_records
end end

View File

@ -6,72 +6,70 @@ describe CanCan::Query do
@ability.extend(CanCan::Ability) @ability.extend(CanCan::Ability)
end end
it "should return array of behavior and conditions for a given ability" do it "should have false conditions if no abilities match" do
@ability.can :read, Person, :first => 1, :last => 3 @ability.query(:destroy, Person).conditions.should == "true=false"
@ability.query(:show, Person).conditions.should == [[true, {:first => 1, :last => 3}]]
end
it "should raise an exception when a block is used on condition, and no hash" do
@ability.can :read, Person do |a|
true
end
lambda { @ability.query(:show, Person).conditions }.should raise_error(CanCan::Error, "Cannot determine SQL conditions or joins from block for :show Person")
end
it "should return an array with just behavior for conditions when there are no conditions" do
@ability.can :read, Person
@ability.query(:show, Person).conditions.should == [ [true, {}] ]
end
it "should return false when performed on an action which isn't defined" do
@ability.query(:foo, Person).conditions.should == false
end end
it "should return hash for single `can` definition" do it "should return hash for single `can` definition" do
@ability.can :read, Person, :blocked => false, :user_id => 1 @ability.can :read, Person, :blocked => false, :user_id => 1
@ability.query(:read, Person).conditions.should == { :blocked => false, :user_id => 1 }
@ability.query(:read, Person).sql_conditions.should == { :blocked => false, :user_id => 1 }
end end
it "should return `sql` for single `can` definition in front of default `cannot` condition" do it "should merge multiple can definitions into single SQL string joining with OR" do
@ability.can :read, Person, :blocked => false
@ability.can :read, Person, :admin => true
@ability.query(:read, Person).conditions.should == "(admin=true) OR (blocked=false)"
end
it "should merge multiple can definitions into single SQL string joining with OR and AND" do
@ability.can :read, Person, :blocked => false, :active => true
@ability.can :read, Person, :admin => true
@ability.query(:read, Person).conditions.should orderlessly_match("(blocked=false AND active=true) OR (admin=true)")
end
it "should merge multiple can definitions into single SQL string joining with OR and AND" do
@ability.can :read, Person, :blocked => false, :active => true
@ability.can :read, Person, :admin => true
@ability.query(:read, Person).conditions.should orderlessly_match("(blocked=false AND active=true) OR (admin=true)")
end
it "should return false conditions for cannot clause" do
@ability.cannot :read, Person
@ability.query(:read, Person).conditions.should == "true=false"
end
it "should return SQL for single `can` definition in front of default `cannot` condition" do
@ability.cannot :read, Person @ability.cannot :read, Person
@ability.can :read, Person, :blocked => false, :user_id => 1 @ability.can :read, Person, :blocked => false, :user_id => 1
result = @ability.query(:read, Person).sql_conditions result = @ability.query(:read, Person).conditions.should orderlessly_match("blocked=false AND user_id=1")
result.should include("blocked=false")
result.should include(" AND ")
result.should include("user_id=1")
end end
it "should return `true condition` for single `can` definition in front of default `can` condition" do it "should return true condition for single `can` definition in front of default `can` condition" do
@ability.can :read, Person @ability.can :read, Person
@ability.can :read, Person, :blocked => false, :user_id => 1 @ability.can :read, Person, :blocked => false, :user_id => 1
@ability.query(:read, Person).sql_conditions.should == 'true=true' @ability.query(:read, Person).conditions.should == 'true=true'
end end
it "should return `false condition` for single `cannot` definition" do it "should return false condition for single `cannot` definition" do
@ability.cannot :read, Person, :blocked => true, :user_id => 1 @ability.cannot :read, Person, :blocked => true, :user_id => 1
@ability.query(:read, Person).sql_conditions.should == 'true=false' @ability.query(:read, Person).conditions.should == 'true=false'
end end
it "should return `false condition` for single `cannot` definition in front of default `cannot` condition" do it "should return `false condition` for single `cannot` definition in front of default `cannot` condition" do
@ability.cannot :read, Person @ability.cannot :read, Person
@ability.cannot :read, Person, :blocked => true, :user_id => 1 @ability.cannot :read, Person, :blocked => true, :user_id => 1
@ability.query(:read, Person).sql_conditions.should == 'true=false' @ability.query(:read, Person).conditions.should == 'true=false'
end end
it "should return `not (sql)` for single `cannot` definition in front of default `can` condition" do it "should return `not (sql)` for single `cannot` definition in front of default `can` condition" do
@ability.can :read, Person @ability.can :read, Person
@ability.cannot :read, Person, :blocked => true, :user_id => 1 @ability.cannot :read, Person, :blocked => true, :user_id => 1
result = @ability.query(:read, Person).sql_conditions result = @ability.query(:read, Person).conditions.should orderlessly_match("not (blocked=true AND user_id=1)")
result.should include("not ")
result.should include("blocked=true")
result.should include(" AND ")
result.should include("user_id=1")
end end
it "should return appropriate sql conditions in complex case" do it "should return appropriate sql conditions in complex case" do
@ -80,8 +78,8 @@ describe CanCan::Query do
@ability.can :update, Person, :manager_id => 1 @ability.can :update, Person, :manager_id => 1
@ability.cannot :update, Person, :self_managed => true @ability.cannot :update, Person, :self_managed => true
@ability.query(:update, Person).sql_conditions.should == 'not (self_managed=true) AND ((manager_id=1) OR (id=1))' @ability.query(:update, Person).conditions.should == 'not (self_managed=true) AND ((manager_id=1) OR (id=1))'
@ability.query(:manage, Person).sql_conditions.should == {:id=>1} @ability.query(:manage, Person).conditions.should == {:id=>1}
@ability.query(:read, Person).sql_conditions.should == 'true=true' @ability.query(:read, Person).conditions.should == 'true=true'
end end
end end

13
spec/matchers.rb Normal file
View File

@ -0,0 +1,13 @@
Spec::Matchers.define :orderlessly_match do |original_string|
match do |given_string|
original_string.bytes.sum == given_string.bytes.sum
end
failure_message_for_should do |given_string|
"expected \"#{given_string}\" to have the same characters as \"#{original_string}\""
end
failure_message_for_should_not do |given_string|
"expected \"#{given_string}\" not to have the same characters as \"#{original_string}\""
end
end

View File

@ -4,6 +4,7 @@ require 'active_support'
require 'active_record' require 'active_record'
require 'action_controller' require 'action_controller'
require 'action_view' require 'action_view'
require 'matchers'
require 'cancan' require 'cancan'
require 'cancan/matchers' require 'cancan/matchers'