How to convert string to existing attribute in model when creation - ruby-on-rails

I got a array of strings, I want to retrieve for each the attribute during the creation of the post.
My array = ["_646_maturity", "_660_maturity", "_651_maturity", "_652_maturity", "_641_maturity"]
class Audit < ApplicationRecord
belongs_to :user
before_save :calculate_scoring
def calculate_scoring
scoring = []
models = ActiveRecord::Base.connection.tables.collect{|t| t.underscore.singularize.camelize.constantize rescue nil}
columns = models.collect{|m| m.column_names rescue nil}
columns[2].each do |c|
if c.include? "maturity"
Rails.logger.debug 'COLUMN : '+c.inspect
scoring.push(c)
end
end
getMaturity = ""
scoring.each do |e|
getMaturity = e.to_sym.inspect
Rails.logger.debug 'MATURITY : '+getMaturity
end
end
end
The log print > 'MATURITY : :_651_maturity'
I'm looking to the value of :_651_maturity who is a attribute of my post.
I tried .to_sym but it's not working..
Thanks for the help!

Inside calculate_scoring you can use self to point to the record you are saving. So self._651_maturity = <some_value>, self[:_651_maturity] = <some_value> and self['_651_maturity'] are all valid methods to set _651_maturity.
Also, you can do something like:
my_attrib = '_651_maturity'
self[my_attrib] = 'foo'

Related

ruby on rails accessing custom class attributes from its object

I have a custom class in my application controller. Like below:
class Defaults
def initialize
#value_1 = "1234"
#value_2 = nil
#data = Data.new
end
end
class Data
def initialize
#data_1 = nil
end
end
Now in my controller method i have created an object of type Defaults
def updateDefaultValues
defaults = Defaults.new
# i am unable to update the value, it says undefined method
defaults.value_2 = Table.maximum("price")
defaults.data.data_1 = defaults.value_2 * 0.3
end
How to access value_2 from defaults object?
defaults.value_2
Also, how to access data_1 attribute from data object within defaults object?
defaults.data.data_1
You should use attr_accessor:
class Defaults
attr_accessor :value_1, :value_2, :data
# ...
end
defaults = Defaults.new
defaults.value_1 = 1
# => 1
defaults.value_1
# => 1
As you are using def as a keyword to define the method, that means def is a reserved keyword. You can't use reserved keywords as a variable.
You just need to rename your variable name from def to something_else and it should work! Your code will look like this:
def updateDefaultValues
obj = Defaults.new
obj.value_2 = Table.maximum("price")
obj.data.data_1
end
EDIT:
As per OP's comment & updated question, he had used def just as an example, here is the updated answer:
You may need attr_accessor to make attrs accessible:
class Defaults
attr_accessor :value_1, :value_2, :data
...
...
end
class Data
attr_accessor :data_1
...
...
end
Add value_2 method in Defaults class
class Defaults
def initialize
#value_1 = "1234"
#value_2 = nil
#data = Data.new
end
def value_2
#value_2
end
end
class Data
def initialize
#data_1 = nil
end
end

Create or Update Rails 4 - updates but also creates (Refactoring)

In my Rails API I have the following code in my Child model:
before_create :delete_error_from_values, :check_errors, :update_child_if_exists
def delete_error_from_values
#new_error = self.values["error"]
#values = self.values.tap { |hs| hs.delete("error") }
end
def update_child_if_exists
conditions = {type: self.type, parent_id: self.parent_id}
if existing_child = Child.find_by(conditions)
new_values = existing_child.values.reverse_merge!(#values)
hash = {:values => new_values}
existing_child.update_attributes(hash)
end
end
def check_errors
if self.type == "error"
conditions = {type: self.type, parent_id: self.parent_id}
if existing_child = Child.find_by(conditions)
bd_errors = existing_child.error_summary
bd_errors[#new_error] = bd_errors[#new_error].to_i + 1
hash = {:error_summary => bd_errors}
existing_child.update_attributes(hash)
else
self.error_summary = {#new_error => 1}
end
end
end
This works like expected, except for one small detail: The Child is updated if a record by type and parent_id already exists, but it is also created. How can I refactor this to stop creation?
I've tried to include return false, but if I do this, the update is not successful.
I wish to have something like find_or_create_by, but I'm not sure how to use it for this cases.
May be you can refactor your code in following approach:
def create
#parent = Parent.find(params[:parent_id])
existing_child = Child.where(type: child_params[:type], parent_id:
child_params[:parent_id]).first
if existing_child.present?
existing_child.update_attributes(attribute: value_1)
else
#child = #parent.child.build(child_params)
end
#other saving related code goes here.
end
This is just a basic piece of example.
Try creating separate instance methods to keep the Contrller DRY. :)

Virtual Column to count record

First, sorry for my English, I am totally new in ruby on rails even in very basic thing, so I hope you all can help me.
I have table Role and RoleUser
table Role have has_many relationship to RoleUser with role_id as foreign key
in table RoleUser is contain user_id, so I can call it 1 role have many users
and I want is to show all record in Role with additional field in every record called total_users,
total_users is in every record have role_id and count the user_id for every role, and put it in total_users,
I know this is must use the join table, but in rails I absolutely knew nothing about that, can you all give me a simple example how to do that.
and one more, same with case above, can I do for example Role.all and then the total_users in include in that without added it in database? is that use virtual column?
anyone have a good source of link to learn of that
I have following code in model
def with_filtering(params, holding_company_id)
order = []
if params[:sort].present?
JSON.parse(params[:sort]).each do |data|
order << "#{data['property']} #{data['direction']}"
end
end
order = 'id ASC' if order.blank?
if self.column_names.include? "holding_company_id"
string_conditions = ["holding_company_id = :holding_company_id"]
placeholder_conditions = { holding_company_id: holding_company_id.id }
else
string_conditions = []
placeholder_conditions = {}
end
if params[:filter].present?
JSON.parse(params[:filter]).each do |filter|
if filter['operation'] == 'between'
string_conditions << "#{filter['property']} >= :start_#{filter['property']} AND #{filter['property']} <= :end_#{filter['property']}"
placeholder_conditions["start_#{filter['property']}".to_sym] = filter['value1']
placeholder_conditions["end_#{filter['property']}".to_sym] = filter['value2']
elsif filter['operation'] == 'like'
string_conditions << "#{filter['property']} ilike :#{filter['property']}"
placeholder_conditions["#{filter['property']}".to_sym] = "%#{filter['value1']}%"
else
string_conditions << "#{filter['property']} = :#{filter['property']}"
placeholder_conditions["#{filter['property']}".to_sym] = filter['value1']
end
end
end
conditions = [string_conditions.join(' AND '), placeholder_conditions]
total_count = where(conditions).count
if params[:limit].blank? && params[:offset].blank?
data = where(conditions).order(order)
else
data = where(conditions).limit(params[:limit].to_i).offset(params[:offset].to_i).order(order)
end
return data, total_count.to_s
end
And I have follwing code in controllers
def crud_index(model)
data, total = Role.with_filtering(params, current_holding_company)
respond_to do |format|
format.json { render json: { data: data, total_count: total }.to_json, status: 200 }
end
end
My only purpose is to add virtual field called total_users, but i want added it in model and combine it with data in method with_filtering
If you have the models like this:
Class Role < ActiveRecord::Base
has_many :role_users
end
Class RoleUser < ActiveRecord::Base
belong_to :role
end
You could use select and joins to generate summary columns, but all the Role's attributes should be include in group.
roles = Role.select("roles.*, count(role_users.id) as total_users")
.joins(:role_users)
.group("roles.id")
Type those scripts in Rails console, Rails will generate a sql like :
SELECT roles.id, count(role_users.id) as total_users
FROM roles
INNER JOIN role_users
ON roles.id = role_users.role_id
GROUP BY roles.id
Then you can use roles.to_json to see the result. The summary column total_users can be accessed in every member of roles.
And there are many other way can match your requirement. Such as this. There is a reference of counter cache.
My suggestion is after searching, you can test those method by rails console, it's a useful tool.
UPDATE
According to OP's update and comment, seems you have more works to do.
STEP1: move with_filtering class method to controller
with_filtering handle a lot of parameter things to get conditions, it should be handled in controller instead of model. So we can transfer with_filtering into conditions and orders in controller.
class RolesController < ApplicationController
def conditions(params, holding_company_id)
if self.column_names.include? "holding_company_id"
string_conditions = ["holding_company_id = :holding_company_id"]
placeholder_conditions = { holding_company_id: holding_company_id.id }
else
string_conditions = []
placeholder_conditions = {}
end
if params[:filter].present?
JSON.parse(params[:filter]).each do |filter|
if filter['operation'] == 'between'
string_conditions << "#{filter['property']} >= :start_#{filter['property']} AND #{filter['property']} <= :end_#{filter['property']}"
placeholder_conditions["start_#{filter['property']}".to_sym] = filter['value1']
placeholder_conditions["end_#{filter['property']}".to_sym] = filter['value2']
elsif filter['operation'] == 'like'
string_conditions << "#{filter['property']} ilike :#{filter['property']}"
placeholder_conditions["#{filter['property']}".to_sym] = "%#{filter['value1']}%"
else
string_conditions << "#{filter['property']} = :#{filter['property']}"
placeholder_conditions["#{filter['property']}".to_sym] = filter['value1']
end
end
end
return [string_conditions.join(' AND '), placeholder_conditions]
end
def orders(params)
ord = []
if params[:sort].present?
JSON.parse(params[:sort]).each do |data|
ord << "#{data['property']} #{data['direction']}"
end
end
ord = 'id ASC' if ord.blank?
return ord
end
end
STEP2: update action crud_index with conditions and orders to get total_count of Roles.
class AnswersController < ApplicationController
def crud_index(model)
total = Role.where(conditions(params, current_holding_company)).count
if params[:limit].blank? && params[:offset].blank?
data = Role.where(conditions(params, current_holding_company)).order(orders(params))
else
data = Role.where(conditions(params, current_holding_company)).limit(params[:limit].to_i).offset(params[:offset].to_i).order(orders(params))
end
respond_to do |format|
format.json { render json: { data: data, total_count: total }.to_json, status: 200 }
end
end
end
STEP3: update action crud_index to get total_users by every role.
Make sure the two previous steps is pass the test.
class AnswersController < ApplicationController
def crud_index(model)
total = Role.where(conditions(params, current_holding_company)).count
if params[:limit].blank? && params[:offset].blank?
data =
Role.select(Role.column_names.map{|x| "Roles.#{x}"}.join(",") + " ,count(role_users.id) as total_users")
.joins(:role_users)
.group(Role.column_names.map{|x| "Roles.#{x}"}.join(","))
.where(conditions(params, current_holding_company))
.order(orders(params))
else
data =
Role.select(Role.column_names.map{|x| "Roles.#{x}"}.join(",") + " ,count(role_users.id) as total_users")
.joins(:role_users)
.group(Role.column_names.map{|x| "Roles.#{x}"}.join(","))
.where(conditions(params, current_holding_company))
.order(orders(params))
.limit(params[:limit].to_i)
.offset(params[:offset].to_i).order(orders(params))
end
respond_to do |format|
format.json { render json: { data: data, total_count: total }.to_json, status: 200 }
end
end
end
NOTE: step3 may need you to modify conditions and orders method to generate column_name with table_name prefix to avoid column name ambiguous error
If you can make these steps through, I suggest you can try will_paginate to simplify the part of your code about total_count ,limit and offset.
With what you explained, you could do something like this:
class Role < ActiveRecord::Base
has_many :role_users
has_many :users
def total_users
self.users.count
end
end
So you just need to call the total_users method on roles object which should get you what you desire. Something like this:
Role.first.total_users
# this will give you the total users for the first role found in your database.
Hope it helps
You might want to watch this Railscast too:
#app/models/role.rb
Class Role < ActiveRecord::Base
has_many :role_users
has_many :users, -> { select "users.*", "role_users.*", "count(role_users.user_id) as total_users" }, through: :role_users
end
This will allow you to call:
#roles = Role.find params[:id]
#roles.users.each do |role|
role.total_users
end
You can see more about how this works with a question I wrote some time ago - Using Delegate With has_many In Rails?
--
It's where I learnt about Alias columns, which Ryan Bates uses to count certain values:

How can I make a delayed job for this custom method?

Here is my Lesson model:
#encoding: utf-8
class Lesson < ActiveRecord::Base
attr_accessible :content, :title, :parsed_content, :html_content, :user_id
serialize :parsed_content, Array
serialize :html_content, Array
serialize :pinyin_content, Array
serialize :defined_content, Array
serialize :literal_content, Array
validates :title, :presence => true
validates :content, :presence => true
belongs_to :user
before_update do |lesson|
lesson.makesandwich
end
before_save do |lesson|
lesson.delay.makesandwich
end
def makesandwich
require 'rmmseg'
#require 'to_lang'
require 'bing_translator'
require 'ruby-pinyin'
self.parsed_content = []
RMMSeg::Dictionary.load_dictionaries
content = self.content
paragraphs = content.split(/\r\n\r\n/) #convert to array of paragraphs
self.parsed_content = paragraphs
paragraphs.each_with_index do |text, ti|
text = text.gsub("。", "^^.")
text = text.gsub("?", "~~?")
text = text.gsub("!", "||!")
text = text.gsub(":", ":") #fix missing colons
text = text.split(/[.?!]/u) #convert to an array
text.each do |s|
s.gsub!("^^", "。")
s.gsub!("~~", "?")
s.gsub!("||", "!")
#s.gsub!("———————————",":")
end
text.each_with_index do |val, index|
algor = RMMSeg::Algorithm.new(text[index])
splittext = []
loop do
tok = algor.next_token
break if tok.nil?
tex = tok.text.force_encoding('UTF-8')
splittext << tex
text[index] = splittext
end
paragraphs[ti] = text
end
end
bing = BingTranslator.new(BING_API)
self.parsed_content = paragraphs
textarray = Marshal.load(Marshal.dump(paragraphs))
self.defined_content = Marshal.load(Marshal.dump(paragraphs))
self.literal_content = Marshal.load(Marshal.dump(paragraphs))
self.pinyin_content = Marshal.load(Marshal.dump(paragraphs))
textarray.each_with_index do |paragraph, pi|
paragraph.each_with_index do |sentence, si|
sentence.each_with_index do |word, wi|
if DictionaryEntry.find_by_simplified(word) != nil
self.defined_content[pi][si][wi] = DictionaryEntry.find_by_simplified(word).definition
#self.literal_content is down below
self.pinyin_content[pi][si][wi] = DictionaryEntry.find_by_simplified(word).pinyin
else
self.defined_content[pi][si][wi] = bing.translate(word, :from => 'zh-CHS', :to => 'en')
#self.defined_content[pi][si][wi] = word
#self.literal_content is down below
if PinYin.of_string(word, true).length > 1 #for punctuation
self.pinyin_content[pi][si][wi] = PinYin.of_string(word, true).join(" ").downcase
else
self.pinyin_content[pi][si][wi] = word
end
end
end
end
end
#Literal
literalarray = Marshal.load(Marshal.dump(paragraphs))
literalarray.each_with_index do |paragraph, pi|
paragraph.each_with_index do |sentence, si| #iterate array of sentence
literalarray[pi][si] = []
sentence.each_with_index do |word, wi| #iterate sentence's array of words
entrytobesliced = DictionaryEntry.find_by_simplified(word)
slicedentry = []
if entrytobesliced == nil
if word.length > 1 && word !~ /\w/ #/^\s*\w\d+\s*$/ #number regex #for cases where there is no DictionaryEntry
split = []
wordarray = word.split("").each_with_index() do |ws, wsi|
split << [DictionaryEntry.find_by_simplified(ws).definition]
end
literalarray[pi][si] << split
else
literalarray[pi][si] << [word] #in case none of the above work
end
else
entrytobesliced.simplified.each_char do |w|
singlechar = DictionaryEntry.find_by_simplified(w)
slicedentry << singlechar.definition.split("\", \"")
end
literalarray[pi][si] << slicedentry
end
self.literal_content = literalarray #slicedentry #literalarray
end
end
end
end
end
When I try to create a new lesson it errors like this: Jobs cannot be created for records before they've been persisted
But if I change it to after_save instead of before_save then I can see the work run, but it doesn't update the serialized arrays in the database.
Can someone please help me implement delayed_jobs for this? It was working when I had:
before_save do |lesson|
lesson.makesandwich #no delay
end
I think you're getting these errors:
Jobs cannot be created for records before they've been persisted
because your Lesson instances won't have an id until they've been saved and without an id, DJ has no way to know which instance it should be working with. So you have to use an after_save so that your Lesson has an id and can be uniquely identified. But then your updates from the delayed job won't be saved because, well, nothing asks for them to be saved. You should be able to get around that simply by adding a self.save or self.save! call at the end of makesandwich.

Rails: Updating two fields of an ActiveRecord instance simultaniously

I have a model, called Book, that has the fields title and filename (and other fields but they are unrelated). I'd like that the filename field was automatically created using the title, thus in my Book.rb:
class Book < ActiveRecord::Base
# ...
def title=(title)
self.filename = sanitize_filename(title)
self.title = title
end
# ...
end
Because of self.title = title it's going in a infinite recursion. How could I avoid that?
Thanks!
You can write that on before_save
def before_save
self.filename = sanitize_filename(self.title)
end
Try this way
class Book
def title=(title)
self.filename = sanitize_filename(title)
self[:title] = title
end
end
There's a section in the ActiveRecord api on 'overwriting default accessors'. The suggested solution there is:
def title=(t)
self.filename = sanitize_filename(t)
write_attribute(:title, t)
end

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