Trying to understand what Base.rakismet_binding is for - ruby-on-rails

What does this part . . .
unless Rakismet::Base.rakismet_binding.nil?
{ :referrer => 'request.referer', :user_ip => 'request.remote_ip',
:user_agent => 'request.user_agent' }.each_pair do |k,v|
data[k] = eval(v, Rakismet::Base.rakismet_binding) || ''
end
end
of the following method do?
module InstanceMethods
def spam?
data = akismet_data
unless Rakismet::Base.rakismet_binding.nil?
{ :referrer => 'request.referer', :user_ip => 'request.remote_ip',
:user_agent => 'request.user_agent' }.each_pair do |k,v|
data[k] = eval(v, Rakismet::Base.rakismet_binding) || ''
end
end
self.akismet_response = Rakismet::Base.akismet_call('comment-check', data)
self.akismet_response == 'true'
end
I found other references to rakismet_binding in rakismet.rb:
class Base
cattr_accessor :valid_key, :rakismet_binding
and controller_extensions.rb:
def rakismet(&block)
Rakismet::Base.rakismet_binding = binding
yield
Rakismet::Base.rakismet_binding = nil
end
private :rakismet
But I have no idea what it's for.

The Kernel binding is a special object holding the context of a method call including all instance variables.
What rakismet(&block) method does, is to temporary assign the current binding (the ActionController instance) to a class variable so it can be accessible by any rakismet method calls and execute the content of the block.
The following code fragment
unless Rakismet::Base.rakismet_binding.nil?
{ :referrer => 'request.referer', :user_ip => 'request.remote_ip',
:user_agent => 'request.user_agent' }.each_pair do |k,v|
data[k] = eval(v, Rakismet::Base.rakismet_binding) || ''
end
end
checks whether a binding is available and if so, it tries to automatically collect some information from the current binding such as the ActionController#request.referer, the ActionController#request.remote_ip and so on.
In a few words, this is a workaround to collect some variables from your current ActionController request that otherwise won't be available to Rakismet.

The last code fragment pretty much indicates its intention - its to be used in block form and wraps the current binding.
If you look at the some unit tests for this class:
http://github.com/jfrench/rakismet/blob/master/spec/models/model_extension_spec.rb?raw=true
You can see how its used.

Related

How to track objects "called" inside a block?

Question:
I need to know the records' attributes that have been called inside a block (say I need something like the following):
def my_custom_method(&block)
some_method_that_starts_tracking
block.call
some_method_that_stops_tracking
puts some_method_that_returns_called_records_attributes
do_something_about(some_method_that_returns_called_records_attributes)
end
my_custom_method { somecodethatcallsauthorofbook1andemailandfirstnameofuser43 }
# this is the `puts` output above (just as an example)
# => {
# #<Book id:1...> => [:author],
# #<User id:43...> => [:email, :first_name]
# }
code inside the block can be anything
Specifically, I meant to track any instance of a subclass of ApplicationRecord, so it can be instance of any models like Book, User, etc...
Attempts:
From my understanding, this is similar to how rspec works when a method is expected to be called. That it somehow tracks any calls of that method. So, my initial attempt is to do something like the following (which does not yet fully work):
def my_custom_method(&block)
called_records_attributes = {}
ApplicationRecord.descendants.each do |klass|
klass.class_eval do
attribute_names.each do |attribute_name|
define_method(attribute_name) do
called_records_attributes[self] ||= []
called_records_attributes[self] << attribute_name
self[attribute_name]
end
end
end
end
block.call
# the above code will work but at this point, I don't know how to clean the methods that were defined above, as the above define_methods should only be temporary
puts called_records_attributes
end
my_custom_method { Book.find_by(id: 1).title }
# => {
# #<Book id: 1...> => ['title']
# }
the .descendants above probably is not a good idea because Rails use autoload if I'm not mistaken
as already said above in the comment, I do not know how to remove these "defined_methods" that are just supposed to be only temporary for the duration of this "block".
furthermore, my code above would probably have overriden the "actual" attribute getters of the models, if ever any has been already defined, which is bad.
Background:
I am writing a gem live_record which I am adding a new feature that will allow a developer to just simply write something like
<!-- app/views/application.html.erb -->
<body>
<%= live_record_sync { #book.some_custom_method_about_book } %>
</body>
... which will render #book.some_custom_method_about_book as-is on the page, but at the same time the live_record_sync wrapper method would take note of all the attributes that have been called inside that block (i.e. inside some_custom_method_about_book the #book.title is called), and then it sets these attributes as the block's own "dependencies", in which later when that specific book's attribute has been updated, I can already also update directly the HTML page of which this attribute is a "dependency" as like specified just above. I am aware that this is not an accurate solution, but I'd like to open up my chances by experimenting on this first.
-- Rails 5
Disclaimer: I believe this is just a mediocre solution, but hopefully helps anyone with the same problem.
I tried reading rspec source code, but because I couldn't easily comprehend what is happening under the hood, and that it occurred to me that rspec's (i.e.) expect(Book.first).to receive(:title) is different from what I really want because the methods there are already specified (i.e. :title), while what I want is to track ANY methods that are attributes, so because of these two reasons I skipped reading further, and attempted my own solution, which hopefully did somehow work; see below.
Note that I am using Thread local-storage here, so this code should be thread-safe (untested yet).
# lib/my_tracker.rb
class MyTracker
Thread.current[:my_tracker_current_tracked_records] = {}
attr_accessor :tracked_records
class << self
def add_to_tracked_records(record, attribute_name)
Thread.current[:my_tracker_current_tracked_records][{model: record.class.name.to_sym, record_id: record.id}] ||= []
Thread.current[:my_tracker_current_tracked_records][{model: record.class.name.to_sym, record_id: record.id}] << attribute_name
end
end
def initialize(block)
#block = block
end
def call_block_while_tracking_records
start_tracking
#block_evaluated_value = #block.call
#tracked_records = Thread.current[:my_tracker_current_tracked_records]
stop_tracking
end
def to_s
#block_evaluated_value
end
# because I am tracking record-attributes, and you might want to track a different object / method, then you'll need to write your own `prepend` extension (look for how to use `prepend` in ruby)
module ActiveRecordExtensions
def _read_attribute(attribute_name)
if Thread.current[:my_tracker_current_tracked_records] && !Thread.current[:my_tracker_is_tracking_locked] && self.class < ApplicationRecord
# I added this "lock" to prevent infinite loop inside `add_to_tracked_records` as I am calling the record.id there, which is then calling this _read_attribute, and then loops.
Thread.current[:my_tracker_is_tracking_locked] = true
::MyTracker.add_to_tracked_records(self, attribute_name)
Thread.current[:my_tracker_is_tracking_locked] = false
end
super(attribute_name)
end
end
module Helpers
def track_records(&block)
my_tracker = MyTracker.new(block)
my_tracker.call_block_while_tracking_records
my_tracker
end
end
private
def start_tracking
Thread.current[:my_tracker_current_tracked_records] = {}
end
def stop_tracking
Thread.current[:my_tracker_current_tracked_records] = nil
end
end
ActiveSupport.on_load(:active_record) do
prepend MyTracker::ActiveRecordExtensions
end
ActiveSupport.on_load(:action_view) do
include MyTracker::Helpers
end
ActiveSupport.on_load(:action_controller) do
include MyTracker::Helpers
end
Usage Example
some_controller.rb
book = Book.find_by(id: 1)
user = User.find_by(id: 43)
my_tracker = track_records do
book.title
if user.created_at == book.created_at
puts 'same date'
end
'thisisthelastlineofthisblockandthereforewillbereturned'
end
puts my_tracker.class
# => #<MyTracker ... >
puts my_tracker.tracked_records
# => {
# {model: :Book, record_id: 1} => ['title', 'created_at'],
# {model: :User, record_id: 43} => ['created_at']
# }
puts my_tracker
# => 'thisisthelastlineofthisblockandthereforewillbereturned'
# notice that `puts my_tracker` above prints out the block itself
# this is because I defined `.to_s` above.
# I need this `.to_s` so I can immediately print the block as-is in the views.
# see example below
some_view.html.erb
<%= track_records { current_user.email } %>
P.S. Maybe it's better that I wrap this up as a gem. If you're interested, let me know

Rails/Ruby incorrectly showing variable not defined

In debugging console, while app running (using binding.pry to interrupt it), I can see that my variable Rails.configuration.hardcoded_current_user_key is set:
pry(#<TasksController>)> Rails.configuration.hardcoded_current_user_key
=> "dev"
But it doesn't appear to be defined:
pry(#<TasksController>)> defined?(Rails.configuration.hardcoded_current_user_key)
=> nil
Yet it works fine to store and test its value:
pry(#<TasksController>)> tempVar = Rails.configuration.hardcoded_current_user_key
=> "dev"
pry(#<TasksController>)> defined?(tempVar)
=> "local-variable"
What is going on?
This is because Rails config implements respond_to? but not respond_to_missing?, and defined? only recognizes respond_to_missing?:
class X
def respond_to?(name, include_all = false)
name == :another_secret || super
end
private
def method_missing(name, *args, &block)
case name
when :super_secret
'Bingo!'
when :another_secret
'Nope.'
else
super
end
end
def respond_to_missing?(name, include_all = false)
name == :super_secret || super
end
end
x = X.new
puts x.super_secret # => Bingo!
p defined?(x.super_secret) # => "method"
puts x.another_secret # => Nope.
p defined?(x.another_secret) # => nil
It's recommended to implement respond_to_missing? along with method_missing, I too wonder why Rails did it that way.
You shouldn't be using defined? on anything but the "stub" of that, or in other words, merely this:
defined?(Rails)
Anything beyond that is highly unusual to see, and I'm not even sure it's valid.
defined? is not a method, but a construct that tests if the following thing is defined as a variable, constant or method, among other things. It won't evaluate your code, it will just test it as-is. This means method calls don't happen, and as such, can't be chained.
If you want to test that something is assigned, then you should use this:
Rails.configuration.hardcoded_current_user_key.nil?

Ruby on Rails: Execute Logic Based on Selected Menu

I have a class that I use to contain select menu options for property types. It works fine. However, I need to be able to verify the selection and perform specific logic based on the selected option. This needs to happen in my Ruby code and in JavaScript.
Here is the class in question:
class PropertyTypes
def self.[](id)
##types[id]
end
def self.options_for_select
##for_select
end
private
##types = {
1 => "Residential",
2 => "Commercial",
3 => "Land",
4 => "Multi-Family",
5 => "Retail",
6 => "Shopping Center",
7 => "Industrial",
8 => "Self Storage",
9 => "Office",
10 => "Hospitality"
}
##for_select = ##types.each_pair.map{|id, display_name| [display_name, id]}
end
What is the best way to verify the selection? I need to perform specific logic and display user interface elements based on each type of property type.
Since I am storing the id, I would be verifying that the id is a particular property type. Something like:
PropertyTypes.isResidential?(id)
Then this method would look like this:
def self.isResidential?(id)
##types[id] == "Residential"
end
But now I am duplicating the string "Residential".
For JavaScript, I assume I would make an ajax call back to the model to keep the verification code DRY, but this seems like over kill.
Do I need to manually create a verification method for each property type or can I use define_method?
This seems so basic yet I am confused and burned out on this problem.
Thanks
===
Here's my solution:
class << self
##types.values.each do |v|
# need to remove any spaces or hashes from the found property type
v = v.downcase().gsub(/\W+/, '')
define_method "is_#{v}?", do |i|
type_name = ##types[i]
return false if type_name == nil #in case a bogus index is passed in
type_name = type_name.downcase().gsub(/\W+/, '')
type_name == v
end
end
end
It sounds like you can benefit from some Ruby meta-programming. Try googling "ruby method_missing". You can probably do something quick & dirty along the lines of:
class PropertyTypes
def method_missing(meth, *args, &block)
if meth.to_s =~ /^is_(.+)\?$/
##types[args.first] == $1
else
super
end
end
end
On the ruby side you could also use something like this to define dynamically these methods:
class << self
##types.values.each do |v|
define_method "is_#{v}?", do |i|
##types[i] == v
end
end
end

How do I pass a var from one model's method to another?

Here is my one model..
CardSignup.rb
def credit_status_on_create
Organization.find(self.organization_id).update_credits
end
And here's my other model. As you can see what I wrote here is an incorrect way to pass the var
def update_credits
#organization = Organization.find(params[:id])
credit_count = #organization.card_signups.select { |c| c.credit_status == true}.count
end
If it can't be done by (params[:id]), what can it be done by?
Thanks!
Ideally the data accessible to the controller should be passed as parameter to model methods. So I advise you to see if it is possible to rewrite your code. But here are two possible solutions to your problem. I prefer the later approach as it is generic.
Approach 1: Declare a virtual attribute
class CardSignup
attr_accessor call_context
def call_context
#call_context || {}
end
end
In your controller code:
def create
cs = CardSignup.new(...)
cs.call_context = params
if cs.save
# success
else
# error
end
end
In your CardSignup model:
def credit_status_on_create
Organization.find(self.organization_id).update_credits(call_context)
end
Update the Organization model. Note the change to your count logic.
def update_credits
#organization = Organization.find(call_context[:id])
credit_count = #organization.card_signups.count(:conditions =>
{:credit_status => true})
end
Approach 2: Declare a thread local variable accessible to all models
Your controller code:
def create
Thread.local[:call_context] = params
cs = CardSignup.new(...)
if cs.save
# success
else
# error
end
end
Update the Organization model. Note the change to your count logic.
def update_credits
#organization = Organization.find((Thread.local[:call_context] ||{})[:id])
credit_count = #organization.card_signups.count(:conditions =>
{:credit_status => true})
end
Use an attr_accessor.
E.g.,
class << self
#myvar = "something for all instances of model"
attr_accessor :myvar
end
#myothervar = "something for initialized instances"
attr_accessor :myothervar
then you can access them as ModelName.myvar and ModelName.new.myvar respectively.
You don't say whether you're using Rails 2 or 3 but let's assume Rails 2 for this purpose (Rails 3 provides the a new DSL for constructing queries).
You could consider creating a named scope for in your Organization model as follows:
named_scope :update_credits,
lambda { |id| { :include => :card_signup, :conditions => [ "id = ? AND card_signups.credit_status = TRUE", id ] } }
And then use it as follows:
def credit_status_on_create
Organization.update_credits(self.organization_id)
end
Admittedly I don't quite understand the role of the counter in your logic but I'm sure you could craft that back into this suggestion if you adopt it.

get a list of objects with roles applied in be9 acl9

I think in something like this:
def self.obj_list(opts = {:include => [] , :exclude => []})
# Returns an array with all objects with roles applied
# +:exclude+:: (array,string) optional object type to exclude from list
# +:include+:: (array,string) optional object type to include in list
# Example:
# Role.obj_list(:include => ["Device", "User"])
# Role.obj_list(:exclude => ["User"])
inc = opts[:include].to_a
exc = opts[:exclude].to_a
objs = []
if inc.empty?
self.all.each do |r|
unless r.authorizable_type.nil?
objs << r.authorizable_type.constantize.find(r.authorizable_id) unless exc.include?(r.authorizable_type)
end
end
else
self.all.each do |r|
unless r.authorizable_type.nil?
objs << r.authorizable_type.constantize.find(r.authorizable_id) if inc.include?(r.authorizable_type)
end
end
end
objs
end
You can use where clauses to do the include/exclude stuff in SQL:
( inc.empty?
? where.not( :authorizable_type => exc )
: where( :authorizable_type => inc )
).map(&:authorizable)
By using authorizable you will get Rails's own handling of polymorphic associations, which will ensure that only actual objects are returned, so there's no need to check for nil
I don't know, maybe you want to link the object and subject?
If is this, here are a tutorial for that: https://github.com/be9/acl9/wiki/tutorial:-linking-object-and-subject-with-hmt

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