My search method is smelly and bloated, and I need some help refactoring it. I'm new to Ruby, and I haven't figured out how to leverage it effectively, which leads to bloated methods like this:
# discussion.rb
def self.search(params)
# If there is a search query, use Tire gem for fulltext search
if params[:query].present?
tire.search(load: true) do
query { string params[:query] }
end
# Otherwise grab all discussions based on category and/or filter
else
# Grab all discussions and include the author
discussions = self.includes(:author)
# Filter by category if there is one specified
discussions = discussions.where(category: params[:category]) if params[:category]
# If params[:filter] is provided, user it
if params[:filter]
case params[:filter]
when 'hot'
discussions = discussions.open.order_by_hot
when 'new'
discussions = discussions.open.order_by_new
when 'top'
discussions = discussions.open.order_by_top
else
# If params[:filter] does not match the above three states, it's probably a status
discussions = discussions.order_by_new.where(status: params[:filter])
end
else
# If no filter is passed, just grab discussions by hot
discussions = discussions.open.order_by_hot
end
end
end
STATUSES = {
question: %w[answered],
suggestion: %w[started completed declined],
problem: %w[solved]
}
scope :order_by_hot, order('...') DESC, created_at DESC")
scope :order_by_new, order('created_at DESC')
scope :order_by_top, order('votes_count DESC, created_at DESC')
This is a Discussion model that can be filtered (or not) by a category: question, problem, suggestion.
All discussions or a single category can be filtered further by hot, new, votes, or status. Status is a hash in the model and it has several values depending on the category (status filter only appears if params[:category] is present).
Complicating matters is a fulltext search feature using Tire
But my controller looks nice and tidy:
def index
#discussions = Discussion.search(params)
end
Can I dry this up/refactor it a little, maybe using meta programming or blocks? I managed to extract this out of the controller, but then ran out of ideas. I don't know Ruby well enough to take this further.
For starters, "Grab all discussions based on category and/or filter" can be a separate method.
params[:filter] is repeated many times, so take that out at the top:
filter = params[:filter]
You can use
if [:hot, :new, :top].incude? filter
discussions = discussions.open.send "order_by_#{filter}"
...
Also, factor out if then else if case else statements. I prefer break into separate methods and return early:
def do_something
return 'foo' if ...
return 'bar' if ...
'baz'
end
discussions = discussions... appears many times, but looks weird. Can you use return discussions... instead?
Why does the constant STATUSES appear at the end? Usually constants appear at the top of the model.
Be sure to write all your tests before refactoring.
To respond to the comment about return 'foo' if ...:
Consider:
def evaluate_something
if a==1
return 'foo'
elsif b==2
return 'bar'
else
return 'baz'
end
end
I suggest refactoring this to:
def evaluate_something
return 'foo' if a==1
return 'bar' if b==2
'baz'
end
Perhaps you can refactor some of your if..then..else..if statements.
Recommended book: Clean Code
Related
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 "))
What I'm trying to do: I have a model "Recipe" in which I defined a method "search" that takes an array of strings from checkboxes (I call them tags), and a single string. The idea is to search the db for recipes that has anything in it's 'name' or 'instructions' that contains the string, AND also has any of the tags matching it's 'tags' property.
Problem: The search method return all the recipes in my db, and doesn't seem to work at all at finding by the specific parameters.
The action method in the controller:
def index
#recipes = Recipe.search(params[:search], params[:tag])
if !#recipes
#recipes = Recipe.all
end
respond_to do |format|
format.html
format.json { render json: #recipe }
end
end
The search method in my model:
def self.search(search, tags)
conditions = ""
search.present? do
# Condition 1: recipe.name OR instruction same as search?
conditions = "name LIKE ? OR instructions LIKE ?, '%#{search[0].strip}%', '%#{search[0].strip}%'"
# Condition 2: if tags included, any matching?
if !tags.empty?
tags.each do |tag|
conditions += "'AND tags LIKE ?', '%#{tag}%'"
end
end
end
# Hämtar och returnerar alla recipes där codition 1 och/eller 2 stämmer.
Recipe.find(:all, :conditions => [conditions]) unless conditions.length < 1
end
Any ideas why it return all records?
if you are using rails 3, then it is easy to chain find conditions
def self.search(string, tags)
klass = scoped
if string.present?
klass = klass.where('name LIKE ? OR instructions LIKE ?', "%#{string}%", "%#{string}%")
end
if tags.present?
tags.each do |tag|
klass = klass.where('tags LIKE ?', "%#{tag}%")
end
end
klass
end
When you do
search.present? do
...
end
The contents of that block are ignored - it's perfectly legal to pass a block to a function that doesn't expect one, however the block won't get called unless the functions decides to. As a result, none of your condition building code is executed. You probably meant
if search.present?
...
end
As jvnill points out, it is in general much nicer (and safer) to manipulate scopes than to build up SQL fragments by hand
Trying to do a basic filter in rails 3 using the url params. I'd like to have a white list of params that can be filtered by, and return all the items that match. I've set up some scopes (with many more to come):
# in the model:
scope :budget_min, lambda {|min| where("budget > ?", min)}
scope :budget_max, lambda {|max| where("budget < ?", max)}
...but what's the best way to use some, none, or all of these scopes based on the present params[]? I've gotten this far, but it doesn't extend to multiple options. Looking for a sort of "chain if present" type operation.
#jobs = Job.all
#jobs = Job.budget_min(params[:budget_min]) if params[:budget_min]
I think you are close. Something like this won't extend to multiple options?
query = Job.scoped
query = query.budget_min(params[:budget_min]) if params[:budget_min]
query = query.budget_max(params[:budget_max]) if params[:budget_max]
#jobs = query.all
Generally, I'd prefer hand-made solutions but, for this kind of problem, a code base could become a mess very quickly. So I would go for a gem like meta_search.
One way would be to put your conditionals into the scopes:
scope :budget_max, lambda { |max| where("budget < ?", max) unless max.nil? }
That would still become rather cumbersome since you'd end up with:
Job.budget_min(params[:budget_min]).budget_max(params[:budget_max]) ...
A slightly different approach would be using something like the following inside your model (based on code from here:
class << self
def search(q)
whitelisted_params = {
:budget_max => "budget > ?",
:budget_min => "budget < ?"
}
whitelisted_params.keys.inject(scoped) do |combined_scope, param|
if q[param].nil?
combined_scope
else
combined_scope.where(whitelisted_params[param], q[param])
end
end
end
end
You can then use that method as follows and it should use the whitelisted filters if they're present in params:
MyModel.search(params)
I am using search logic to filter results on company listing page. The user is able to specify any number of parameters using a variety of named URLs. For example:
/location/mexico
/sector/technology
/sector/financial/location/argentina
Results in the following respectively:
params[:location] == 'mexico'
params[:sector] == 'technology'
params[:sector] == 'financial' and params[:location] == 'argentina'
I am now trying to cleanup or 'DRY' my model code. Currently I have:
def self.search(params)
...
if params[:location]
results = results.location_permalink_equals params[:location] if results
results = Company.location_permalink_equals params[:location] unless results
end
if params[:sector]
results = results.location_permalink_equals params[:sector] if results
results = Company.location_permalink_equals params[:sector] unless results
end
...
end
I don't like repeating the searchs. Any suggestions? Thanks.
This is how I would write it:
[params[:location], params[:sector]].reject(&:nil?).each do |q|
results = (results ? results : Company).location_permalink_equals q
end
There's plenty of other ways, just an idea. Has the benefit of making it easy to add say params[:street] or something.
I don't think you can really DRY that up much when sticking to SearchLogic... I'd suggest to refine your routes to directly emit *_permalink as parameter names and do something like this:
Company.all :conditions => params.slice(:location_permalink, :sector_permalink)
or
Company.find :all, :conditions => params.slice(:location_permalink, :sector_permalink)
Documentation link: http://api.rubyonrails.org/classes/ActiveSupport/CoreExtensions/Hash/Slice.html