How to trim input in rails models globally - ruby-on-rails

In my Rails app there are several models where users are posting data to the database. Lots of this data has trailing and leading whitespaces. Is there a way I can globally strip all input's leading and trailing whitespaces?
I'd like to avoid doing this for every field in every model, seems like there could be a global way to handle this during a before_save.
Any used techniques out there?
Thanks

One more gem to do this job: https://github.com/holli/auto_strip_attributes
Also in some cases you want to squish the data user has inputted to get rid of multiple spaces inside the variable. E.g. with names or nicks.
gem "auto_strip_attributes", "~> 1.0"
class User < ActiveRecord::Base
auto_strip_attributes :name, :nick, :nullify => false, :squish => true
end
All the gems and other approaches work a bit the same way by using before_save callback. (Code example is in Jeremys example.) So there might be some issues with custom setters. You can choose to do it with
attributes.each do before_validation do ...
record.send("#{attr_name}=", record.send(attr_name).to_s.strip)
or with
attributes.each do before_validation do ...
record[attribute] = record.send(attr_name).to_s.strip)
First approach will call setter twice (once when setting, once in before_validation). The second will call setter only once but will alter the data after the call to setter.

Here is one simple way to do it on selected attributes:
module ActiveRecord
module Acts
module AttributeAutoStripper
def self.included(base)
base.extend(ClassMethods)
end
module ClassMethods
def acts_as_attribute_auto_stripper (*names)
class_eval <<-EOV
include ActiveRecord::Acts::AttributeAutoStripper::InstanceMethods
before_validation :auto_strip_selected_attributes
def auto_strip_attributes
#{names.inspect}
end
EOV
end
end
module InstanceMethods
def auto_strip_selected_attributes
if auto_strip_attributes
auto_strip_attributes.each do |attr_name|
self.send("#{attr_name}=", self.send(attr_name).to_s.strip) unless self.send(attr_name).blank?
end
end
end
end
end
end
end
ActiveRecord::Base.send :include, ActiveRecord::Acts::AttributeAutoStripper
and then in your model:
class User < ActiveRecord::Base
acts_as_attribute_auto_stripper :name, :email
end

If users are posting data to the DB through a form, you could create a before filter method that'll strip the parameters. Put that in the Application controller.
I hope this helps :)

This fork of the StripAttributes plugin may do the trick for you:
https://github.com/fragility/strip_attributes

You could create an ActiveRecord subclass with a before_save filter that strips all attributes. Then, make all of your models a subclass of this new class.

Related

Why do functions from my Rails plugin not work without specifically requiring?

I need some help with my plugin. I want to extend ActiveRecord::Base with a method that initializes another method that can be called in the controller.
It will look like this:
class Article < ActiveRecord::Base
robot_catch :title, :text
...
end
My attempt at extending the ActiveRecord::Base class with robot_catch method looks like following. The function will initialize the specified attributes (in this case :title and :text) in a variable and use class_eval to make the robot? function available for the user to call it in the controller:
module Plugin
module Base
extend ActiveSupport::Concern
module ClassMethods
def robot_catch(*attr)
##robot_params = attr
self.class_eval do
def robot?(params_hash)
# Input is the params hash, and this function
# will check if the some hashed attributes in this hash
# correspond to the attribute values as expected,
# and return true or false.
end
end
end
end
end
end
ActiveRecord::Base.send :include, Plugin::Base
So, in the controller, this could be done:
class ArticlesController < ApplicationController
...
def create
#article = Article.new(params[:article])
if #article.robot? params
# Do not save this in database, but render
# the page as if it would have succeeded
...
end
end
end
My question is whether if I am right that robot_catch is class method. This function is to be called inside a model, as shown above. I wonder if I am extending the ActiveRecord::Base the right way. The robot? function is an instance method without any doubt.
I am using Rails 3.2.22 and I installed this plugin as a gem in another project where I want to use this functionality.
Right now, it only works if I specifically require the gem in the model. However, I want it the functionality to be included as a part of ActiveRecord::Base without requiring it, otherwise I'd have to require it in every model I want to use it, not particularly DRY. Shouldn't the gem be automatically loaded into the project on Rails start-up?
EDIT: Maybe callbacks (http://api.rubyonrails.org/classes/ActiveSupport/Callbacks/ClassMethods.html) would be a solution to this problem, but I do not know how to use it. It seems a bit obscure.
First, I would suggest you make sure that none of the many many built in Rails validators meet your needs.
Then if that's the case, what you actually want is a custom validator.
Building a custom validator is not as simple as it might seem, the basic class you'll build will have this structure:
class SpecialValidator < ActiveModel::EachValidator
def validate_each(record, attribute, value)
# Fill this with your validation logic
# Add to record.errors if validation fails
end
end
Then in your model:
class Article < ActiveRecord::Base
validates :title, :text, special: true
end
I would strongly suggest making sure what you want is not already built, chances are it is. Then use resources like this or ruby guides resources to continue going down the custom validator route.
Answer
I found out the solution myself. Bundler will not autoload dependencies from a gemspec that my project uses, so I had to require all third party gems in an engine.rb file in the lib/ directory of my app in order to load the gems. Now everything is working as it should.
Second: the robot_catch method is a class method.

Rails: Concern with before_filter type of method

I am just getting my hands on Concerns in Rails and try to implement a simple logging for ActiveRecord classes. In there I want to define the field that should go into the log and have the log written automatically after save.
What I have is this:
#logable.rb (the concern)
module Logable
extend ActiveSupport::Concern
#field = nil
module ClassMethods
def set_log_field(field)
#feild = field
end
end
def print_log
p "LOGGING: #{self[#index.to_s]}"
end
end
#houses.rb (the model using the concern)
class House < ActiveRecord::Base
include Logable
after_save :print_log
set_log_field :id
end
Unfortunately the call to set_log_field does not have an effect - or rather the given value does not make it to print_log.
What am I doing wrong?
Thanks for your help!
You probably mean this (btw, why not Loggable?):
# logable.rb
module Logable
extend ActiveSupport::Concern
# Here we define class-level methods.
# Note, that #field, defined here cannot be referenced as #field from
# instance (it's class level!).
# Note also, in Ruby there is no need to declare #field in the body of a class/module.
class_methods do
def set_log_field(field)
#field = field
end
def log_field
#field
end
end
# Here we define instance methods.
# In order to access class level method (log_field), we use self.class.
included do
def print_log
p "LOGGING: #{self.class.log_field}"
end
end
end
Update You also asked about what's the difference between methods in included block and those within method body.
To make a short resume there is seemingly no difference. In very good approximation you can consider them the same. The only minor difference is in dependency management. Great illustration of it is given in the end of ActiveSupport::Concern documentation. It worth reading, take a look!

Refactored way of titleizing values from a model (Rails)

I have trouble thinking of a way on how to shorten my process on titleizing values upon rendering them in my view.
I did some custom getters for the following attributes that I need to titleize. Here's my example.
user.rb
class User < ActiveRecord::Base
def department
read_attribute(:department).titleize
end
def designation
read_attribute(:designation).titleize
end
end
This method works but it seems a hassle when I want to do this to other models as well.
Is there a more efficient way to handle this which can be used by other models? If you'll mention Draper (since I don't seem to find on how to titleize selected attributes), how can I accomplish using this gem? But, I would prefer not using a gem but instead, create a custom one.
Not tested this, but you could use a Concern with added modules to handle it
--
Modularity
I found a gem called modularity which basically allows you to pass parameters to a concern & other modules. This means if you can pass the params you wish to "titleize", you may be able to pull it off like this:
#Gemfile
gem 'modularity', '~> 2.0.1'
#app/models/concerns/titleize.rb
module Titleize
extend ActiveSupport::Concern
as_trait do |*fields|
fields.each do |field|
define_method("#{field}") do
self[field.to_sym] = field.titleize
end
end
end
end
#app/models/your_model.rb
Class YourModel < ActiveRecord::Base
include Titleize[:your, :params]
end
If you want those value always titleized, what you are doing is fine, but I would actually apply the method on the setters, not on the getters, so you only do it once per record instead of at each read:
def department=(s)
write_attribute(:department, s.to_s.titleize) # The to_s is in case you get nil/non-string
end
If this is purely for presentation (ie, you want the not titleized version in the database, then it can be done in a presenter using Draper:
class UserDecorator < Draper::Decorator
delegate_all
def designation
object.designation.titleize
end
end
(or another rails presenter).

Before Create in Active Record

I would like to setup a before_create for all of my modules
what i have been trying is:
module ActiveRecord
module UserMonitor
require 'securerandom'
before_create :attach_uuid
def attach_uuid
self.uuid = SecureRandom.uuid.gsub("-","")
end
end
end
This does not seem to be working.
if i go into each module and add it in there it works, but i want to do it on a global scale.
Any thoughts or ideas on how i can achieve this in this manner? i know i could do it in triggers and such but i don't want to go that route and i would like to avoid hitting every module/class in case i need to change something.
Currently using Ruby 1.9.3 Can not currently upgrade my app until i make future code changes.
Thanks!
An other solution - I use, is to put the logic for UUID in an own module, that you include. I already have some (class-) methods I add to my AR, like set_default_if, so it was a good place for me.
module MyRecordExt
def self.included base
base.extend ClassMethods # in my case some other stuff
base.before_create :attach_uuid # now add the UUID
end
def attach_uuid
begin
self.uuid = SecureRandom.uuid
rescue
# do the "why dont we have a UUID filed?" here
end
end
# some other things not needed for add_uuid
module ClassMethods
include MySpecialBase # just an eg.
def default_for_if(...)
...
end
end
end
and then
class Articel < ActiveRecord::Base
include MyRecordExt
...
end
In general I avoid doing something for ALL models modifying AR base - I made the first bad experience with adding the UUID to all, and crashed with devise GEMs models ...
If you define attach_uuid in the ActiveRecord module, can't you just call the before_create :attach_uuid at the top of each controller? This is DRY.
Is there a UserMonitor controller that you could add it to?
class UserMonitor < ActiveRecord::Base
before_create :attach_uuid
end

Rails 3.2. Override validates_presence_of behavior

I'm writing a Redmine plugin and added some fields to issues form via hooks (the fields are also added to Issue table), so far so good. Now I want to make those fields mandatory, but can't figure out how to 'override' validates_presence_of behavior for Issue model.
I've created a hook for Issue save method, in order to check presence of my new fields before saving, but not sure if this is the best way to go. Is it possible to just extend Issue model so that it validates for presence of my new fields?
You can add validations on new fields in you plugin. Example is here
# load plugin file(s)
Rails.configuration.to_prepare do
TimeEntry.send(:include, TimeLimitTimeEntryPatch)
end
# in patch file
module TimeLimitTimeEntryPatch
def self.included(base)
base.send(:include, InstanceMethods)
base.class_eval do
unloadable
validates_presence_of :comments
validate :validate_time_limit_allowed_ip
end
end
module InstanceMethods
def validate_time_limit_allowed_ip
# add error if permission is not set and IP is not allowed
if !self.class.have_permissions?(user, project) && !time_limit_allowed_ip
errors.add(:hours, I18n.t(:not_allowed_ip))
end
end
end
end
Alternatively:
1) Create extension somewhere in your lib directory (make sure that it is required):
module IssueExtensions
extend ActiveSupport::Concern
included do
validates_presence_of :new_attr
end
end
2) Send it to Issue model. Good place for this could be config/initializers/extensions.rb (must be initialized after Redmine obviously):
Issue.send(:include, IssueExtensions)

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