Rails Pass Params/Arguments to Activerecord Callback Function

Rails pass params/arguments to ActiveRecord callback function

There are four types of callbacks accepted by the callback macros: Method references (symbol), callback objects, inline methods (using a proc), and inline eval methods (using a string).

Try this?

after_update -> { cache_bust(true) }

Pass custom argument to rails event model callbacks?

No, it is not possible to pass variables to callback method. Reason is simple as callback methods are called by rails stack and when it will call callback method, it did't know what to pass in callback method.

Pass parameter to callback in Rails

You have:

belongs_to :user, foreign_key: :user_id

in your Favorite model and limit_records is an instance method on Favorite. So you have access to the user as self.user_id (or just user_id since self is implied) inside limit_records and there is no need for an argument:

after_create :limit_records

def limit_records
  # same as what you have now, `user_id` will be `self.user_id`
  # now that there is no `user_id` argument...
  count = self.where(user_id: user_id).count
  self.where(used_id: user_id).last.delete if count > 10
end

Pass parameter to callback in the controller

To pass in parameters, you have to use a block.

before_filter(only: [:show]) { permit_show(@project) }
before_filter(only: [:edit]) { permit_edit(@project) }

How to pass params into a model callback method in rails?

I'm not an experienced railer, but I think it would work if you simply use a property of your model to store this value.

something like:

my_class.member = 'a-member'

class MyClass
  after_update :reprocess_image

  def reprocess_image
    do_something_with_your self.member
  end

end

Rails: Can you pass arguments to the after_create method?

You could use attr_accessor to create a virtual attribute and set that attribute as part of your create action.

Rails Model callback: Passing field as parameter to callback classes?

You may do this or use normalize_attributes gem

module StripFieldsCallback
  def before_validation_z(field)
    write_attribute(field, read_attribute(field).strip) if read_attribute(field)
  end
end

class User < ActiveRecord::Base
  include StripFieldsCallback

  before_validation   lambda{|data| data.before_validation_z(:name)}
end

pass parameters to before_create callback in rails 3

I think you can store the message and the receivers of the message with the help of Ajax in the database. That way you can continue with the message after wards similar to gmail.

Another option is to have 2 different submits for "Send" and "Save as Draft" on the form and based on commit parameter you can process the message.

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