Changing JSON field names in Rails responses - ruby-on-rails

I need to allow for customization of json output per account. One person may like the standard json response. Another may wish to have the exact same feed except they need the "name" field called "account_name" or something.
So with a standard user they may be happy with
#model.to_json(only: [:name, :title, :phone])
Another user may wish to see their json response as
#model.to_json(only: [:name (AS ACCOUNT_NAME) , :title, :phone])
I have found solutions that override the as_json/to_json in the model but those seem to be solutions that effect everyone. How can I change them just on a per access/per account basis?

I think in your case, it is better to push the logic to the view layer to make the code clean by using Jbuilder.
so instead of override to_json method you can do something like below:
# app/views/users/show.json.jbuilder
json.model_name do
json.title #current_user.title
json.phone #current_user.phone
if current_user.type_account_name? # need to implement this logic somewhere in your app
json.account_name #current_user.name
else
json.name #current_user.name
end
end
update
the controller looks something like this
class UsersController < ApplicationController
def show
#user = User.find(params[:id])
end
end

Related

Strong parameters issue with custom controller?

I'm using acts_as_taggable_on plugin in conjunction with my User model.
acts_as_taggable_on :skills
Now, I have a custom controller called SkillsController to add skills via ajax.
class SkillController < ApplicationController
def add
current_user.skill_list.add(params[:skill])
current_user.save # Not saving!
end
end
and in routes.rb
get 'skill/:skill', to: 'skill#add'
I guess it has to do something with Strong Parameters, but I don't know how to solve it as it stands.
The current_user.save isn't working, how to solve it.
P.S current_user.errors shows #message is "too short" as per my validations. But how do I just save the skill_list without having to modify other attributes or running validations on them?
If you want to save current_user without validation check you can do just like as:
current_user.save(:validate => false)
This will work for you :)

Ruby - How to define params for require()?

questions_controller.rb
def index
#questions = Question.all(app_params)
end
private
def app_params
params.require(:questions).permit(:question, :answer)
end
end
question.rb
class Question < ActiveRecord::Base
end
I am completely new to ruby-on-rails. I was following a guide and it said I should take care of some "loopholes" or "security issues" and it used attr_accessible, but on Rails 4, they suggest strong parameters, so now I'm trying to use them. I'm confused on how to define the :questions params, because I'm currently getting an error saying that :questions param is not found.
:questions is pretty much something that I will define myself as the web developer.
So for example, I will define questions = "How are you?", "What is your name?". I'm basically starting very simply. I want questions that I have created to be displayed on my webpage. Ultimately, I plan to make a website what is basically a list of questions and, with answer options. After the user clicks "submit" I want to store the information into my database.
Am I supposed to even be requiring this as a param? I'm completely lost..
Do you have a dump of the params we could look at? They are shown when your app encounters an error, and typically shows you the params array which rails will pass through
Strong Params In Rails 4
Strong Params allow you to allow certain parameters for use in the controller, protecting against any malicious assignment client-side. They replaced attr_accessible in Rails 4.0
Strong Params is only for user-submitted content, as it's designed to protect the params hash. To that end, it's mostly used with the create and find functions:
class PeopleController < ActionController::Base
# Using "Person.create(params[:person])" would raise an
# ActiveModel::ForbiddenAttributes exception because it'd
# be using mass assignment without an explicit permit step.
# This is the recommended form:
def create
Person.create(person_params)
end
# This will pass with flying colors as long as there's a person key in the
# parameters, otherwise it'll raise an ActionController::MissingParameter
# exception, which will get caught by ActionController::Base and turned
# into a 400 Bad Request reply.
def update
redirect_to current_account.people.find(params[:id]).tap { |person|
person.update!(person_params)
}
end
private
# Using a private method to encapsulate the permissible parameters is
# just a good pattern since you'll be able to reuse the same permit
# list between create and update. Also, you can specialize this method
# with per-user checking of permissible attributes.
def person_params
params.require(:person).permit(:name, :age)
end
end
params.require
The params.require function works by taking this params hash:
params{:question => {:question => "1", :answer => "5"}}
That's why people asked what your params hash looks like, because the require function can only work if the :question hash is present.
Possible Solutions For You
Question.all(app_params)
Regardless of what you're trying to achieve, don't use all. The where function is better for receiving an array of data based on certain values. I believe all is depreciated anyway.
def index
#questions = Question.where("value = ?", variable)
end
What data is being passed?
I will define questions = "How are you?", "What is your name?"
This is okay, but typically in rails, you'd call data by using an ID in the database. If you're defining these questions in a form, you'd use the strong params system; but you'd need a form to submit the data to
Further Additions
The rails way is to keep all your data in a database, and use the application to manipulate that data, either by showing it, or allowing people to input more.
The "params" variables are basically there to help the rails controllers & models accept & process data from end users, and consequently allow you to keep the system growing. Instead of having to write custom code to accommodate all sorts of different data, the params give you a rigid structure to work with. Here is a good explaination of how MVC (and params) works for you: How does an MVC system work?
I think you're getting confused with how your app should work
Your "questions" should be stored in a questions table / model, and can be accessed by calling their ID's with the find function. This code would be like this:
#app/controllers/questions_controller.rb
def show
#question = Question.find(params[:id])
end
If you want to add new questions, you'll be best to add them to the questions table, like this:
#app/controllers/questions_controller.rb
def new
#question = Question.new
end
def create
#question = Question.new(question_params)
#question.save
end
private
def question_params
params.require(:question).permit(:question)
end
#app/views/questions/new.html.erb
<%= form_for #question do |f| %>
<%= f.text_field :question %>
<% end %>
This will give you a central store of your questions, which you'll then be able to access when you need them, either with a helper or with your ".all" call :)
Give it a shot with question (singular):
params.require(:question).permit(:text, :answer)
Assuming question is your model and text (which I made up) is the wording of the question.

Sanitizing input

this may be a really n00b question, but if your list of params contains a bunch of stuff that isn't an attribute accessible, ie
params = {"controller"=>"api1/users", "action"=>"create"}
what is the best way to "sanitize" your params so that they only contain the accessible attributes. The current way that I thought of currently is to do :
User._accessible_attributes[:default].entries
that gives me a list of accessible attributes and then only pass those params:
["", "email", "password", "fb_token", "fb_id", "fb_name", "first_name", "last_name", "gender"
Another possible way is to have this:
def clean_params #ANTIPATTERN
params.delete(:controller)
params.delete(:action)
end
but this also feels like an antipattern...
I know that you're supposed to do something like params[:user] to get only the accessible params, but because this is an API, it would be nice to be able to pass things just in the url.
Thanks!
The Rails parameter wrapper will do this for you automatically. That is, it will accept parameters at the top level and group them under, for example, :user for your convenience, filtering out any that are not accessible to the User model. Internally it uses accessible_attributes, similar to what you've done. People who use your API will not need to group attributes -- rails will do it before it hands the params to your controller action.
By default it's turned on for JSON requests, but you can expand that by editing initializers/wrap_parameters.rb. Or you can adjust the behavior on a per-controller basis using the wrap_parameters method in your controller.
The rails scheme of parameter sanitizing is likely to change in 4.0, trending away from the model and toward the controller. You may want to watch development of the strong_parameters gem which could be a preview of things to come.
You could do it this way... This will only sense in the parameters you want to in the controller. credit: dhh's gist
class UserController < ApplicationController
respond_to :html
def create
respond_with User.create(user_params)
end
private
def user_params
params[:user].slice(:email, :first_name, :last_name)
end
end

Processing data before saving to database

I have decimal field in my DB. Users can input values in two formats: with comma or point (11,11 or 11.11).
But MySQL allows to save data only in 'point' format, so i want to process data before saving with regex like this:
sub(/,/,".")
How can i do it in Rails3?
If I understand you correctly, this could be done in the controller or the model. I might use the before_save callback in the model to achieve this in the following way:
class Item < ActiveRecord::Base
before_save :standardise_numbers
...
protected
# Called before this object is saved to the DB
def standardise_numbers
self.number.sub!(",", ".")
end
end
Where number is the attribute you're wanting to convert.
I assume you don't need to convert it back to comma representation to display to the user? If you do, you may want to look into the internationalisation API for Rails, Il8n. It handles this kind of stuff and more, so definitely worth looking into.
Alternative Solution (edit)
Based on your feedback, my above solution doesn't work since the number is already converted and the decimal part lost when it is passed into the model. A similar piece of code could be used in the controller to intercept and convert the number in the params hash itself:
class PostController < ActionController
before_filter :standardise_numbers, :only => [ :create, :update ]
def create
#post = Post.create(params[:post])
end
protected
# Intercepts the params hash
def standardise_numbers
params[:post][:number].sub!(",", ".")
end
end
This simplifies the create and update methods, allowing you to deal with the hash in the same way you normally would.
I played this it and found this:
Suppose what in form field number, user inputs value '12,13'.
Value from form go to PostController to 'create' method
class PostController < ApplicationController
def create
#post = Post.new(params[:post])
#on this step instance of Post model created, validated and filled with relevant values
#so #post.number == '12' #(decimal), it cuts ',13'
#we need to redefine #post.number
#post.number = params[:post][:number].gsub(/,/,'.').to_f # => 12.13
#and after that save the post
#post.save
end

Rails: modify form parameters before modifying the database

I'm working on a Rails app that sends data through a form. I want to modify some of the "parameters" of the form after the form sends, but before it is processed.
What I have right now
{"commit"=>"Create",
"authenticity_token"=>"0000000000000000000000000"
"page"=>{
"body"=>"TEST",
"link_attributes"=>[
{"action"=>"Foo"},
{"action"=>"Bar"},
{"action"=>"Test"},
{"action"=>"Blah"}
]
}
}
What I want
{"commit"=>"Create",
"authenticity_token"=>"0000000000000000000000000"
"page"=>{
"body"=>"TEST",
"link_attributes"=>[
{"action"=>"Foo",
"source_id"=>1},
{"action"=>"Bar",
"source_id"=>1},
{"action"=>"Test",
"source_id"=>1},
{"action"=>"Blah",
"source_id"=>1},
]
}
}
Is this feasible? Basically, I'm trying to submit two types of data at once ("page" and "link"), and assign the "source_id" of the "links" to the "id" of the "page."
Before it's submitted to the database you can write code in the controller that will take the parameters and append different information before saving. For example:
FooController < ApplicationController
def update
params[:page] ||= {}
params[:page][:link_attributes] ||= []
params[:page][:link_attriubtes].each { |h| h[:source_id] ||= '1' }
Page.create(params[:page])
end
end
Edit params before you use strong params
Ok, so (reviving this old question) I had a lot of trouble with this, I wanted to modify a param before it reached the model (and keep strong params). I finally figured it out, here's the basics:
def update
sanitize_my_stuff
#my_thing.update(my_things_params)
end
private
def sanitize_my_stuff
params[:my_thing][:my_nested_attributes][:foo] = "hello"
end
def my_things_params
params.permit(etc etc)
end
You should also probably look at callbacks, specifically before_validate (if you're using validations), before_save, or before_create.
It's hard to give you a specific example of how to use them without knowing how you're saving the data, but it would probably look very similar to the example that Gaius gave.

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