Working on final class project. I need to calculate the GPA of my major credits and non major credits separately for a transcript page. When I run this code below as a controller it works fine and show my total credit hours for major and non major but when I put this code
#GPA_for_major = (course.credits * course.grade.scale) / course.credits
in the If statement I get NoMethodError in TransController#transcript
undefined method 'credits' for # Course::ActiveRecord_Relation:0x00000007b99798>
class Transcript
def initialize (course_array)
#course = course_array
#total_non_major_credits = 0
#total_major_credits = 0
#GPA_for_major = 0
#GPA_for_non_major = 0
for item in #course
if item.is_for_major
#total_major_credits = #total_major_credits + item.credits
else
#total_non_major_credits = #total_non_major_credits + item.credits
end
end
end
def course
#course
end
def total_non_major_credits
#total_non_major_credits
end
def total_major_credits
#total_major_credits
end
def GPA_for_major
#GPA_for_major
end
def GPA_for_non_major
#GPA_for_non_major
end
end
This is the Controller for my transcript page
class TransController < ApplicationController
def transcript
#courses = Course.all
#transcript =Transcript.new(#courses)
end
end
I'm not sure what else to include because this is my first post but any help will be awesome! Thanks!
#course appears to refer to an array of courses and the if statement is within a loop that iterates over the items setting a local variable item for each course. Given that, you should use item instead of course:
#GPA_for_major = (item.credits * item.grade.scale) / item.credits
Related
I'm working on a project with a goal of POSTing a string and returning every third character of that string. The project is built in Ruby/Rails.
I have the (hacky) logic down for getting that third element out, putting it in a new string, and saving this new string it with the new object in the database, but my issue at the moment is that all of this logic is done in the Controller. I'd really like to follow MVC, so my goal is to get all of this logic into the Model.
Currently, the *params and create methods in my Controller look like this:
Class TestController < ApplicationController
...
def create
new_output_string = params[:input_string].split("")
final_output_string_array = []
counter = 1
new_output_string.each do |letter|
if counter % 3 == 0
final_output_string_array.append(letter)
end
counter = counter + 1
end
final_output_string = final_output_string_array.join("")
#test = Test.create(
input_string: params[:input_string],
output_string: final_output_string
)
render json: #test
end
def test_params
params.require(:test).permit(:input_string, :output_string)
end
So you can see that all of the logic for manipulating this data is in the Controller. I tried writing a method make_output_string in the model:
Class Test < ApplicationRecord
def self.make_output_string()
new_output_string = params[:input_string].split("")
final_output_string_array = []
counter = 1
new_output_string.each do |letter|
if counter % 3 == 0
final_output_string_array.append(letter)
end
counter = counter + 1
end
#final_output_string = final_output_string_array.join("")
end
I hoped that this would manipulate the data before the create action (I tried using before_create etc.) calling before_create, and referencing the method in the controller's create method, but I either get no result or an undefined method error.
How can I move my logic into the Model so that it can handle the manipulation/creation of the parameters?
You should create a custom setter for input_string on the Model and make it save both input_string and output_string.
Class Test < ApplicationRecord
def input_string=(input_string)
super(input_string)
self.output_string = generate_output(input_string)
end
private
def generate_output(input_string)
new_output_string = input_string.split("")
final_output_string_array = []
counter = 1
new_output_string.each do |letter|
if counter % 3 == 0
final_output_string_array.append(letter)
end
counter = counter + 1
end
final_output_string_array.join("")
end
end
Then your controller would be like the following.
Class TestController < ApplicationController
def create
#test = Test.create(input_string: params[:input_string])
render json: #test
end
def test_params
params.require(:test).permit(:input_string, :output_string)
end
end
I've followed multiple stack overflow posts regarding this same issue, but I don't think I have the rails proficiency to know how to apply these fixes to my code.
Been following an old railscast show: http://railscasts.com/episodes/217-multistep-forms
And I'm aware that the issue is something to do with permitting objects/hashes but I just don't understand it all.
The error I'm getting is from this line of code in my controller:
session[:zerch_params].deep_merge!(params[:zerch]) if params[:zerch]
Controller
class ZerchesController < InheritedResources::Base
def index
#zerches = Zerch.all
end
def show
#zerch = Zerch.find(params[:id])
end
def new
session[:zerch_params] ||= {}
#zerch = Zerch.new(session[:zerch_params])
#zerch.current_step = session[:zerch_step]
end
def create
session[:zerch_params].deep_merge!(params[:zerch]) if params[:zerch]
#zerch = Zerch.new(session[:zerch_params])
#zerch.current_step = session[:zerch_step]
if #zerch.valid?
if params[:back_button]
#zerch.previous_step
elsif #zerch.last_step?
#zerch.save if #zerch.all_valid?
else
#zerch.next_step
end
session[:zerch_step] = #zerch.current_step
end
if #zerch.new_record?
render "new"
else
session[:zerch_step] = session[:zerch_params] = nil
flash[:notice] = "zerch complete!"
redirect_to #zerch
end
end
private
def zerch_params
params.require(:zerch).permit(:location, :category, :price)
end
end
So I was able to solve this from the model and in the controller:
I still had
attr_accessor
while also having params in private. I removed this, and also in the controller I changed the line of code from this:
session[:zerch_params].deep_merge!(params[:zerch]) if params[:zerch]
to this:
session[:zerch_params].deep_merge!(params.permit![:zerch]) if params[:zerch]
Hi I create a controller Game to display a Q/A game
And I am blocked with <<, here is the code
def play
lvlup(lvl)
if lvl == 1
set_questions
else
get_questions
end
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
#answer ||= []
#answers << question.answer
#answers = #answers.shuffle
render 'play'
end
I create an array and I put the related answer in the global answers I want to display 4 Max.
Why does the undefined is here?
Here is the total code
class GamesController < ApplicationController
attr_accessor :lvl
def welcome
end
def congrat
end
def play
lvlup(lvl)
if lvl == 1
set_questions
else
get_questions
end
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
#answer ||= []
#answers << question.answer
#answers = #answers.shuffle
render 'play'
end
def loose
#question = Question.find(params[:question])
flash.now[:alert] = "Miss..."
render 'loose'
end
def check
#lvl = params[:lvl].to_i
answer_id = params[:id].to_i
question = Question.find(params[:question])
if #lvl == lvlmax
render action: 'congrat' and return
elsif answer_id == question.answer_id
flash.now[:notice] = "Well done !"
play
else answer_id != question.answer_id
loose
end
end
private
def lvlup(value)
#lvl = 1 + value.to_i
end
def lvlmax
#lvlmax = Question.all.count
end
def set_questions
#questionsids = []
Question.all.shuffle.each do |d|
#questionsids << d.id
end
cookies[:questions] = #questionsids
end
def get_questions
#questions = cookies[:questions].split('&')
end
def questions
#questions = cookies[:questions]
end
def question
#question = Question.find(questions[lvl])
end
end
Thank you for your help.
You are trying to append to the #answers result - this is an ActiveRecord relation, you cannot append data to that array.
Add .to_a in the end of your line where you set #answers to allow you to append to the array.
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()").to_a
mtrolle's answer might be correct, but I have my doubts as to why ActiveRecord::Relation was not returned as Array by default. (Also as mentioned by BroiStatse in his comment.)
I too noticed the same problem with my local setup however it was attributed to another issue all together. I am sharing this here in case you too happen to use MySQL.
Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
returns an ActiveRecord::Relation object. And it translates to following SQL:
SELECT `answers`.* FROM `answers` WHERE (id != ID) ORDER BY RANDOM() LIMIT 2
When I try running the same in MySQL, I get:
ERROR 1305 (42000): FUNCTION database.RANDOM does not exist
Apparently MySQL does not have RANDOM() function, instead it uses RAND().
Converting ActiveRecord query accordingly returned correct Array to me:
Answer.where.not(id: question.answer_id).limit(2).order("RAND()")
Hi in the following code although the where query inside create method i.e. variable #count_of_fav_texts_present fetches 1 record in the rails console, but in controller the value of #count_of_fav_texts_present is zero and going inside the first if clause.
Also in the internal if clause the query for find_by i.e variable var_fav_text is giving NilClass. Although when I check it in console the value is not Nil, and it has one record.
I am very new to Rails and I am not sure what mistake I am making. Please help.
class NewfavoriteTextsController < ApplicationController
before_action :set_text
before_action :set_favgroup
before_action :authenticate_user!
def create
#count_of_fav_texts_present = Favorite.where(favorited_id: #text_id, user_id: current_user.id).count
if #count_of_fav_texts_present == 0
if Favorite.create(favorited: #text, user: current_user)
if Newfavorite.create(favorite_group_id: #fav_group, newfavorited: #text)
var_fav_text = Favorite.find_by(favorited_id: #text_id, user_id: current_user.id)
cnt_of_var = var_fav_text.counter
var_fav_text.counter = cnt_of_var + 1
var_fav_text.save
else
# do something
end
else
# do something
end
else
# for condition when var is greater than 0
if Newfavorite.create(favorite_group_id: #fav_group, newfavorited: #text)
var_fav_text = Favorite.find_by(favorited_id: #text_id, user_id: current_user.id)
cnt_of_var = var_fav_text.counter
var_fav_text.counter = cnt_of_var + 1
var_fav_text.save
else
# do something
end
end
end
def destroy
# do something
end
private
def set_text
#text = Text.find(params[:text_id] || params[:id])
end
def set_favgroup
#fav_group = params[:fav_group_id]
end
end
Thanks in advance.
I have two methods in two different controllers (Posts & Boards). They are almost same. The difference is only model-instance-association name. To DRY this I think to write the method in module, but how to share it between Post and Board?
def init_post_comments
#user = current_user
a = #user.posts.pluck(:id) # not very nice...
b=params[:post_ids] ||= []
b = b.map(&:to_i)
follow = b - a
unfollow = a - b
follow.each do |id| # checkbox just checked
#post = Post.find_by_id(id)
if #post.users.empty?
#post.update_attribute(:new_follow, true)
end
#user.posts << #post
end
unfollow.each do |id| # if checkbox was unchecked
#post = Post.find_by_id(id)
remove_post_from_user(#post)# here we destroy association
end
if follow.size > 0
get_post_comments_data
end
redirect_to :back
end
UPDATE Ok, if I'll move the methods to model's concern how I should work with associations here? Here #user.posts.pluck(:id) and here #user.boards.pluck(:id) with what I can replace posts and boards so it can work with both of them?
So, I did it! I don't know if it's right way, but I DRY this code.
Two controllers:
posts_controller.rb
def init_comments
if Post.comments_manipulator(current_user, params[:post_ids] ||= []) > 0
#posts = Post.new_post_to_follow
code = []
#posts.each do |post|
group = post.group
code = code_constructor('API.call')
end
Post.comments_init(get_request(code), #posts)
end
redirect_to :back
end
boards_controller.rb
def init_comments
if Board.comments_manipulator(current_user, params[:board_ids] ||= []) > 0
#boards = Board.new_board_to_follow
code = []
#boards.each do |board|# подготовка запроса
group = board.group
code = code_constructor('API.call')
end
Board.comments_init(get_request(code), #boards)
end
redirect_to :back
end
As you can see they are absolutely same.
In models board.rb and post.rb - include CommentsInitializer
And in models\concerns
module CommentsInitializer
extend ActiveSupport::Concern
module ClassMethods
def comments_manipulator(user, ids)
relationship = self.name.downcase + 's'
a = user.send(relationship).pluck(:id)
b = ids.map(&:to_i)
follow = b - a
unfollow = a - b
follow.each do |id| # start to follow newly checked obj
#obj = self.find_by_id(id)
if #obj.users.empty?
#obj.update_attribute(:new_follow, true)
end
user.send(relationship) << #obj
end
unfollow.each do |id| # remove from following
#obj = self.find_by_id(id)
remove_assoc_from_user(#obj, user)#destroy relation with current user
end
follow.size
end
def comments_init(comments, objs)
i = 0
objs.each do |obj| # updating comments data
if comments[i]['count'] == 0
obj.update(new_follow: false)
else
obj.update(new_follow: false, last_comment_id: comments[i]['items'][0]['id'])
end
i += 1
end
end
def remove_assoc_from_user(obj, user)
user = user.id
if user
obj.users.delete(user)
end
end
end
My code works. If you know how to make it better please answer!