I have some complicated boolean methods that I want to use as a filter for Database query results. I want a solution that would work for both SQL and Mongoid DB.
class Bar < ActiveRecord::Base OR include Mongoid::Document
[field :some_field]
def method1?
...
end
def method1?
...
end
This is what I would like to write :
def self.someFunc
Bar.where(some_field: some_value).filter(method1?, method2?)
end
Is there a simpler way than do do that :
def self.someFunc
results = Array.new
Bar.where(some_field: some_value).each do |result|
if result.filter1? && result.filter2?
results << result
end
end
results
end
Okay actually I've used three different techniques to achieve my goal : named_scopes, boolean functions, and array filtering
This link explains array filtering
In my code (using both named_scopes, regexp, and filtering) :
# Named scopes :
scope :current_team, ->{ where(mandate: Constants.mandate)}
# Boolean function :
def prez?
self.role.downcase =~ /.*pre[sident|z].*/
end
# Array filtering :
def self.prez
Bar.current_team.select {|admin|admin.prez?}
end.first
Related
I have multiple controllers. and I have a method to filter like this.
def filter(filtering_params)
results = where(nil)
filtering_params.each do |key, value|
results = results.public_send(key, value) if value.present?
end
results
end
and from controllers, I will call index or show APIs using filtering params for example like this.
def filtering_params
params.slice(:status, :created_at, :id, :transaction_datetime, :portfolio_external_reference_id, :file_id, :file_name)
end
which I will use while fetching from API like this.
def index
records = Module::Class.filter(filtering_params)
render json: {
data: records
}
end
I want to write a generic method that can be used in cases where I want all the available attributes in the particular model as the filtering_params. is there any better way than writing all the attributes?
I solved it and it's working for me.
def filter_params(params)
values = params.slice(*column_names.map(&:to_sym))
filter(values)
end
In a Rails 5.1 app, I have a query object (PORO) named CoolProducts.
class CoolProducts
def self.call(relation = Product.all)
...
# return an instance of Product::ActiveRecord_Relation
end
end
Now I need to limit the found Products based on the fact the name matches a string.
The following works
CoolProducts.call.where("name ILIKE ?", "%#{string}%")
However, I'd like to encapsulate the matching login within the CoolProducts class allowing to do something like
CoolProducts.call.including_in_name(string)
But I'm not sure where to start from.
Any ideas?
It will be difficult if you want any of your methods to be chainable or return ActiveRecord::Relation.
If you consider explicitly fetching the records when you're done chaining being ok, this should work:
class CoolProducts
def initialize(relation)
#relation = relation
end
def self.call(relation = Product.all)
new(relation).apply_scopes
end
attr_reader :relation
alias_method :fetch, :relation
def including_in_name(string)
tap { #relation = relation.where("name ILIKE ?", string) }
end
def apply_scopes
tap { #relation = relation.where(price: 123) }
end
end
Usage:
CoolProducts.call.including_in_name(string).fetch
I'm trying to build a simple search form in Ruby on Rails, my form is simple enough basically you select fields from a series of options and then all the events matching the fields are shown. The problem comes when I leave any field blank.
Here is the code responsible for filtering the parameters
Event.joins(:eventdates).joins(:categories).where
("eventdates.start_date = ? AND city = ? AND categories.name = ?",
params[:event][:date], params[:event][:city], params[:event][:category]).all
From what I get it's that it looks for events with any empty field, but since all of them have them not empty, it wont match unless all 3 are filled, another problem arises when I try to say, look events inside a range or array of dates, I'm clueless on how to pass multiple days into the search.
I'm pretty new to making search forms in general, so I don't even know if this is the best approach, also I'm trying to keep the searches without the need of a secialized model.
Below is probably what you are looking for. (Note: If all fields all blank, it shows all data in the events table linkable with eventdates and categories.)
events = Event.joins(:eventdates).joins(:categories)
if params[:event]
# includes below where condition to query only if params[:event][:date] has a value
events = events.where("eventdates.start_date = ?", params[:event][:date]) if params[:event][:date].present?
# includes below where condition to query only if params[:event][:city] has a value
events = events.where("city = ?", params[:event][:city]) if params[:event][:city].present?
# includes below where condition to query only if params[:event][:city] has a value
events = events.where("categories.name = ?", params[:event][:category]) if params[:event][:category].present?
end
To search using multiple days:
# params[:event][:dates] is expected to be array of dates.
# Below query gets converted into an 'IN' operation in SQL, something like "where eventdates.start_date IN ['date1', 'date2']"
events = events.where("eventdates.start_date = ?", params[:event][:dates]) if params[:event][:dates].present?
It will be more easy and optimised . If you use concern for filter data.
Make one concern in Model.
filterable.rb
module Filterable
extend ActiveSupport::Concern
module ClassMethods
def filter(filtering_params)
results = self.where(nil)
filtering_params.each do |key, value|
if column_type(key) == :date || column_type(key) ==
:datetime
results = results.where("DATE(#{column(key)}) = ?",
Date.strptime(value, "%m/%d/%Y")) if
value.present?
else
results = results.where("#{column(key)} Like ? ", "%#{value}%") if
value.present?
end
end
results
end
def resource_name
self.table_name
end
def column(key)
return key if key.split(".").count > 1
return "#{resource_name}.#{key}"
end
def column_type(key)
self.columns_hash[key].type
end
end
end
Include this concern in model file that you want to filter.
Model.rb
include Filterable
In your controller Add this methods
def search
#resources = Model.filter(class_search_params)
render 'index'
end
def class_search_params
params.slice(:id,:name) #Your field names
end
So, It is global solution. You dont need to use query for filter. just add this concern in your model file.
That's it.
I created a simple web form where users can enter some search criteria to look for venues e.g. a price range. When a user clicks "find" I use active record to query the database. This all works very well if all fields are filled in. Problems occur when one or more fields are left open and therefore have a value of null.
How can I work around this in my controller? Should I first check whether a value is null and create a query based on that? I can imagine I end up with many different queries and a lot of code. There must be a quicker way to achieve this?
Controller:
def search
#venues = Venue.where("price >= ? AND price <= ? AND romance = ? AND firstdate = ?", params[:minPrice], params[:maxPrice], params[:romance], params[:firstdate])
end
You may want to filter out all of the blank parameters that were sent with the request.
Here is a quick and DRY solution for filtering out blank values, triggers only one query of the database, and builds the where clause with Rails' ActiveRecord ORM.
This approach safeguards against SQL-injection, as pointed out by #DanBrooking. Rails 4.0+ provides "strong parameters." You should use the feature.
class VenuesController < ActiveRecord::Base
def search
# Pass a hash to your query
#venues = Venue.where(search_params)
end
private
def search_params
params.
# Optionally, whitelist your search parameters with permit
permit(:min_price, :max_price, :romance, :first_date).
# Delete any passed params that are nil or empty string
delete_if {|key, value| value.blank? }
end
end
I would recommend to make method in Venue
def self.find_by_price(min_price, max_price)
if min_price && max_price
where("price between ? and ?", min_price, max_price)
else
all
end
end
def self.find_by_romance(romance)
if romance
where("romance = ?", romance)
else
all
end
end
def self.find_by_firstdate(firstdate)
if firstdate
where("firstdate = ?", firstdate)
else
all
end
end
And use it in your controller
Venue
.find_by_price(params[:minPrice], params[:maxPrice])
.find_by_romance(params[:romance])
.find_by_firstdate(params[:firstdate])
Another solution to this problem, and I think a more elegant one, is using scopes with conditions.
You could do something like
class Venue < ActiveRecord::Base
scope :romance, ->(genre) { where("romance = ?", genre) if genre.present? }
end
You can then chain those, which would work as an AND if there is no argument present, then it is not part of the chain.
http://guides.rubyonrails.org/active_record_querying.html#scopes
Try below code, it will ignore parameters those are not present
conditions = []
conditions << "price >= '#{params[:minPrice]}'" if params[:minPrice].present?
conditions << "price <= '#{params[:maxPrice]}'" if params[:maxPrice].present?
conditions << "romance = '#{params[:romance]}'" if params[:romance].present?
conditions << "firstdate = '#{params[:firstdate]}'" if params[:firstdate].present?
#venues = Venue.where(conditions.join(" AND "))
So I have a form where users can input a price. I'm trying to make a before_validation that normalizes the data, clipping the $ if the user puts it.
before_validation do
unless self.price.blank? then self.price= self.price.to_s.gsub(/\D/, '').to_i end
end
If user inputs $50 This code is giving me 0. If user inputs 50$ this code gives me 50. I think since the data type is integer that rails is running .to_i prior to my before_validation and clipping everything after the $. This same code works fine if the data type is a string.
Anyone have a solution that will let me keep the integer datatype?
One way is to override the mechanism on the model that sets the price, like this:
def price=(val)
write_attribute :price, val.to_s.gsub(/\D/, '').to_i
end
So when you do #model.price = whatever, it will go to this method instead of the rails default attribute writer. Then you can convert the number and use write_attribute to do the actual writing (you have to do it this way because the standard price= is now this method!).
I like this method best, but for reference another way to do it is in your controller before assigning it to the model. The parameter comes in as a string, but the model is converting that string to a number, so work with the parameter directly. Something like this (just adapt it to your controller code):
def create
#model = Model.new(params[:model])
#model.price = params[:model][:price].gsub(/\D/, '').to_i
#model.save
end
For either solution, remove that before_validation.
I would define a virtual attribute and do my manipulation there allowing you to format and modify both the getter and setter at will:
class Model < ActiveRecord::Base
def foo_price=(price)
self.price = price... #=> Mods to string here
end
def foo_price
"$#{price}"
end
You also might want to note that:
"$50.00".gsub(/\D/, '').to_i #=> 5000
My soluction
colum price type decimal
t.decimal :price, precision: 12, scale: 6
# app/concern/sanitize_fields.rb
module SanitizeFields
extend ActiveSupport::Concern
def clear_decimal(field)
return (field.to_s.gsub(/[^\d]/, '').to_d / 100.to_d) unless field.blank?
end
def clear_integer(field)
field.to_s.strip.gsub(/[^\d]/, '') unless field.blank?
end
# module ClassMethods
# def filter(filtering_params)
# results = self.where(nil)
# filtering_params.each do |key, value|
# results = results.public_send(key, value) if value.present?
# end
# results
# end
#
# #use
# #def index
# # #products = Product.filter(params.slice(:status, :location, :starts_with))
# #end
#
# end
end
#app/controllers/products_controller.rb
include SanitizeFields
params[:product][:price] = clear_decimal(params[:product][:price])