Tag: ruby,for-loop,coding-style,iterator
Ruby has support for the for i in a syntax, but no one really uses it. One of the design principles of Ruby is it's readability, and I find
for i in a
...
end
much more readable (and easier to type) than
a.each do |i|
...
end
Why is it not preferred? Do others not also find it more readable? Is it for consistency reasons, e.g., relation with other functions like each_with_index and variable scoping?
For me, it's uniform syntax. When I am going to do something with array a, I just start typing a.. What am I going to do? Filter? a.select; determine the size? a.size. Iterate? a.each etc.
Iterating an array is nothing special and requires no special language construct. Also eachwithout an immediate block results in an Enumerator, which can be chained with other methods.
Then again, Ruby does have a fine for i in a loop. So if you are more comfortable with a for loop: by all means, use a for loop.
Maybe it makes extract the planet as another model? def Planet enum type: %w(earth mars jupiter) end class PlanetEdge < ActiveRecord::Base belongs_to :first_planet, class_name: 'Planet' belongs_to :second_planet, class_name: 'Planet' end You can create a PlanetEdge by using accepts_nested_attributes_for: class PlanetEdge < ActiveRecord::Base belongs_to :first_planet, class_name: 'Planet' belongs_to :second_planet, class_name: 'Planet'...
Assuming you have properly named the input values, e.g.: <input name="topay[0]" type="checkbox"> <input name="loadnum[0]" value="5"> <input name="unit[0]" value="101"> <input name="driver[0]" value="joe"> <input name="topay[1]" type="checkbox"> <input name="loadnum[1]" value="6"> <input name="unit[1]" value="103"> <input name="driver[1]" value="mike"> Take note of the topay[0] and topay[1] notation that I'm using, as opposed to your form input...
Normally we'd use a loop do with a guard clause: x = 1 loop do break if x >= y x += 1 ... end Make sure y is larger than x or it'll never do anything. y can change if necessary and as long as it's greater than x...
ruby-on-rails,ruby,ruby-on-rails-4
In your associations instead of fac_allocs you need to use a symbol because rails is looking a variable or method named fac_allocs instead of your associated model has_many :facs, through: :fac_allocs ...
Here is a way using an intermediate hash-of-hash The h ends up looking like this {"Alaska"=>{"Rain"=>"3", "Snow"=>"4"}, "Alabama"=>{"Snow"=>"2", "Hail"=>"1"}} myArray = [["Alaska","Rain","3"],["Alaska","Snow","4"],["Alabama","Snow","2"],["Alabama","Hail","1"]] myFields = ["Snow","Rain","Hail"] h = Hash.new{|h, k| h[k] = {}} myArray.each{|i, j, k| h[i][j] = k } p [["State"] + myFields] + h.map{|k, v| [k] + v.values_at(*myFields)} output...
ruby-on-rails,ruby,refactoring
You can change your routes : resources :techs, :only => [:index, :show], shallow: true do resources :cars, only: [:new, :create] collection do get 'part/:part_name' => "techs#part", as: :part end end Then add the action : def part @techs = Tech.joins(:services).where(services: { name: params[:part_name]}) end and the view will be :...
ruby-on-rails,ruby,url,path,less
You should use the font_url, and put the font in app/assets/fonts @font-face { font-family: 'SomeFont'; src: font_url("db92e416-da16-4ae2-a4c9-378dc24b7952.eot?#iefix"); //... } ...
Your migration file named should correspond to AddWeightToExercises. It should be accordingly xxxxxxxx_add_weight_to_exercises, where xxxxxxx corresponds to a particular timestamp.
Short answer: no, you cant. 2.1.5 :001 > 0001 => 1 0001 doesn't make sense at all as Integer. In the Integer world, 0001 is exactly as 1. Moreover, the number of leading integer is generally irrelevant, unless you need to pad some integer for displaying, but in this case...
You should use ljust: arr = [477, 4770] strings = arr.map { |number| number.to_s.ljust(5) } # => ["477 ", "4770 "] Good luck!...
Based on your code where you're filling your 4D list: List<string> Lijst1D = new List<string>(); Lijst2D.Add(Lijst1D); Here you're creating new List<string> and adding it to parent 2D list. But Lijst1D itself doesn't contains any elements (you haven't added anything to it), so Lijst4D[0] will throw that IndexOutOfRangeException as well as...
ruby-on-rails,ruby,ruby-on-rails-4,activerecord
It's not "through Hash", it's "array access" operator. To implement it, you need to define methods: def [](*keys) # Define here end def []=(*keys, value) # Define here end Of course, if you won't be using multiple keys to access an element, you're fine with using just key instead of...
ruby-on-rails,ruby,ruby-on-rails-4,model-view-controller
You can use content_for and yields to create a default in your layout which views can override. # layouts/application.html.erb: <% if content_for?(:banner) %> <%= yield(:banner) %> <% else %> <div id="banner"> <h1>This is the default...</h1> </div> <% end %> /users/signup.html.erb: <%- content_for :banner, flush: true do -%> <!-- move along,...
ruby-on-rails,ruby,authentication
@user.keys.each do |key| username == key.api_id && password == key.api_key end This piece of code returns a value of .each, which is the collection it's called on (@user.keys in this case). As it is a truthy value, the check will pass always, regardless of what are the results of evaluating...
You may utilize integer part of the table to store keys in order: function add(t, k, v, ...) if k ~= nil then t[k] = v t[#t+1] = k return add(t, ...) end return t end t = add({ }, "A", "hi", "B", "my", "C", "name", "D", "is") for i,k...
ruby-on-rails,ruby,rest,activerecord,one-to-many
Take a look at merit gem. Even if you want to develop your own badge system from scratch this gem contains plenty of nice solutions you can use. https://github.com/merit-gem/merit
ruby-on-rails,ruby,ruby-on-rails-3,memory,heroku
That log excert is from a one off dyno, a la heroku run console - this is entirely seperate to your web dynos which you may be runnning 2x dyno's for. You need to specifiy --size=2x in your heroku run command to have the one off process use 2x dynos.
Just as a loop is introduced by for, does not imply the same behaviour for different languages. Python's for loop iterates over objects. Something like the C-for loop does not exist. The C for loop (for ( <init> ; <cond> ; <update> ) <statement>, however, is actually identical to the...
ruby-on-rails,ruby,rack,multipart
Telling it short, this value limits the amount of simultaneously opened files for multipart requests. To understand better what is multipart, you can see this question. The reason for this limitation is an ability to better adjust your app for your server. If you have too many files opened at...
You need add another level like p = Pathname.new('dir/.') now the directory name is "dir"...
You are trying to write a python code using ruby syntax. This is not a best approach to GTD. Slashes are handled right-to-left, yielding not what you expected. As soon as one finds herself putting three or more backslashes inside the string, she should admit, she’s doing it wrong. At...
ruby-on-rails,ruby,rspec,rake-task
A couple things. First off, you should put created_at in the create method: user.items.create(description: "Old Item", created_at: 12.days.ago). Second, you need to call user.reload in order for the changes from your rake task to be available. So it should look like this: user.reload expect(user.items.count).to eq 1 etc...
This code will work: ruby -pi -e 'sub(/^/,"New line goes at top\n") if $FILENAME != $F;$F = $FILENAME' file* ...
ruby-on-rails,ruby,ruby-on-rails-4
You should pass actions to the included block and perform_search_on to the class_methods block. module Searchable extend ActiveSupport::Concern class_methods do def perform_search_on(klass, associations = {}) ............. end end included do def filter respond_to do |format| format.json { render 'api/search/filters.json' } end end end end When your Searchable module include a...
What you are doing will access the fourth character of String s. Split the string to an array and then access the fourth element as follows. puts s.split[3] Note: Calling split without parameters separates the string by whitespace. Edit: Fixing indexes. The index starts from 0. That means s.split[3] will...
Use [[ or [ if you want to subset by string names, not $. From Hadley's Advanced R, "x$y is equivalent to x[["y", exact = FALSE]]." ## Create input input <- `names<-`(lapply(landelist, function(x) sample(0:1, 1)), landelist) filterland <- c() for (landeselect in landelist) if (input[[landeselect]] == TRUE) # use `[[`...
Change if to while: while ["user_4", "user_5"].include?(@randUser = @redis.spop("users")) do @redis.sadd("users", @randUser) end $user_username = @redis.hget(@randUser, "username") $user_password = @redis.hget(@randUser, "password") Please note, that you actually mixed up receiver and parameters on Array#include?...
You can try : dateLabels = <%= raw @mapped_dates.as_json %>; This will return ["Jan 1", "Jan 2", "Jan 3", ... ] For ActiveSupport::TimeWithZone problem, please do - In config/initializers/time_zone.rb class ActiveSupport::TimeWithZone def as_json(options = {}) if ActiveSupport::JSON::Encoding.use_standard_json_time_format xmlschema else %(#{time.strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)}) end end end ...
This operation is called scan or prefix_sum, but unfortunately, there is no implementation in the Ruby core library or standard libraries. However, your intuition is correct: you can implement it using Enumerable#inject. (Actually, Enumerable#inject is general, every iteration operation can be implemented using inject!) module Enumerable def scan(initial) inject([initial]) {|acc,...
javascript,arrays,ruby,iteration
You are looking for the Array.prototype.some method: var match = arr.some(function(w) { return w.indexOf('z') > -1; }); ...
Don't know what the surrounding code looks like so let's assume your code is the entire body of a method. Then a guard clause might look like this: def some_method return if params[:"available_#{district.id}"] != 'true' @deliverycharge = @product.deliverycharges.create!(districtrate_id: district.id) delivery_custom_price(district) end ...
Ok, so the problem is that the code you have is being loaded as soon as the compiled .js file loads. You need to run the code once the DOM is ready. The easy way to do this in volt is to run it on a {action}_ready method: module Main...
Try to use css instead of xpath, this will work for you, doc = Nokogiri::XML(response.body) values = doc.css('Name').select{|name| name.text}.join',' puts values => Ram,Sam ...
You don't need to create a new variable for each image, try this: for var i = 1; i < 8; i++ { images.append(UIImage(named: "image\(i)")) } This loop will create an array with 8 images without create the variables image1 to image8. I hope that help you!...
ruby-on-rails,arrays,ruby,multidimensional-array
dup does not create a deep copy, it copies only the outermost object. From that docs: Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference. dup copies the tainted state of obj. If you are not sure how deep your object...
ruby-on-rails,ruby,ruby-on-rails-4,ruby-on-rails-3.2
So, the complex part of your situation is that you have one thing (Surgery) that can be of many different types, and the different types have different fields. There are a number of different approaches to this problem, and I don't believe there's wide consensus on the 'best way'. The...
ruby-on-rails,ruby,ruby-on-rails-4,twitter
If you express the relation properly, ActiveRecord will do it for you class Tweet belongs_to :original_tweet, class_name: Tweet has_many :retweets, class_name: Tweet, dependent: :destroy, inverse_of :original_tweet end Tweet.last.destroy # will now destroy dependents ...
ruby,page-object-gem,rspec3,rspec-expectations
The Page-Object gem's attribute method does not do any formatting of the attribute value. It simply returns what is returned from Selenium-WebDriver (or Watir-Webdriver). In the case of boolean attributes, this means that true or false will be returned. From the Selenium-WebDriver#attribute documentation: The following are deemed to be “boolean”...
Change required (in github notation): - myFunction(submitArgs()) + myFunction(*submitArgs) The reason that [I assume] myFunction is declared taking two arguments: def myFunction a1, a2 Hence the array must be splatted before passing to it. I wonder how that worked in 1.8....
[a, b, c].count(true) < 2 ........................
str = <<'TEXT' hello %s \\\hline %s TEXT name = "Graig" msg = "Goodbye" puts str % [name, msg] The heredoc does not have escape chars when it's delimiter is in single quotes. It does have a form of interpolation. The code above has this output: hello Graig \\\hline Goodbye...
sql,ms-access,table,for-loop,iteration
I have tested your code, I do not see any issues except for the fact, your For statement is a bit off and that you needed to set the db object. Try this code. Sub toto() Dim db As Database, i As Integer Set db = CurrentDb For i =...
ruby-on-rails,ruby,validation,ruby-on-rails-4,associations
Found this : Validating nested association in Rails (last chapter) class User belongs_to :organization, inverse_of: :users validates_presence_of :organization_id, :unless => 'usertype==1' end class Organization has_many :users accepts_nested_attributes_for :users, :reject_if => :all_blank, :allow_destroy => true end The documentation is not quite clear about it but I think it's worth a try....
The reason is that after finding the first result, the regex engine continues its walk at the position after this first result. So the zero at the end of the first result can't be reuse for an other result. The way to get overlapping results is to put your pattern...
ruby,process,output,fork,spawn
There are a whole bunch of ways to run commands from Ruby. The simplest for your case is to use backticks, which capture output: `sleep 10; date` # "Tue Jun 23 10:15:39 EDT 2015\n" If you want something more similar to Process.spawn, use the open3 stdlib: require 'open3' stdin, stdout,...
Yes, this bookkeeping with i is usually a sign there should be something better. I came up with: ar =[ { name: "foo1", location: "new york" }, { name: "foo2", location: "new york" }, { name: "foo3", location: "new york" }, { name: "bar1", location: "new york" }, { name:...
collection_select internally relies on options_from_collection_for_select helper. Rather than using the collection_select directly, you can use select and pass the result of a options_from_collection_for_select call. The reason you may want to call options_from_collection_for_select directly, is because this method also accepts an optional selected parameter that could be used to pass a...
\d+(?:[,.]\d+)? Try this.This should do it for you....
I would do: def get_days(wkn, *desired_days) get_week = Model.week(2) get_days_of_week = get_week.select { |x| desired_days.include? x.strftime("%A") } end ...
The i++ is using post increment, so the value of the expression i++ is what the value was in the variable i before the increment. This code: if(sortedLetters[i] !== sortedLetters[i++]) return true; does the same thing as: if(sortedLetters[i] !== sortedLetters[i]) return true; i = i + 1; As x !==...