Tutorial by Examples: u

Sometimes it can be useful to set your application locale based upon the request IP. You can easily achieve this using Geocoder. Among the many things Geocoder does, it can also tell the location of a request. First, add Geocoder to your Gemfile # Gemfile gem 'geocoder' Geocoder adds location...

We can check the status of migrations by running 3.05.0 rake db:migrate:status 5.0 rails db:migrate:status The output will look like this: Status Migration ID Migration Name -------------------------------------------------- up 20140711185212 Create documentation pages up ...

In order to compile and run SystemVerilog code a tool called a simulator is needed. Most commonly, commercial tools from one of the Big Three EDA companies is used: Cadence Incisive Mentor Graphics QuestaSim Synopsys VCS Other EDA vendors also provide simulators: Aldec Riviera-PRO Xilinx...

An easy way to clone an object is by implementing a copy constructor. public class Sheep { private String name; private int weight; public Sheep(String name, int weight) { this.name = name; this.weight = weight; } // copy constructor // copies...

Start using File Uploads in Rails is quite simple, first thing you have to do is to choice plugin for managing uploads. The most common onces are Carrierwave and Paperclip. Both are similar in functionality and rich in documentation on Let's have an look on example with simple avatar upload image w...

If you want to create multiple uploads, first thing you might want to do is create new model and set up relations Let's say you want an multiple images for the Product model. Create an new model and make it belongs_to your parent model rails g model ProductPhoto #product.rb has_many :product_p...

GCD will guarantee that your singleton only gets instantiated once, even if called from multiple threads. Insert this into any class for a singleton instance called shared. + (instancetype)shared { // Variable that will point to the singleton instance. The `static` // modifier makes it ...

To differentiate between plural and singular strings, you can define a plural in your strings.xml file and list the different quantities, as shown in the example below: <?xml version="1.0" encoding="utf-8"?> <resources> <plurals name="hello_people&quo...

You can rescue a RecordNotFound exception with a redirect instead of showing an error page: class ApplicationController < ActionController::Base # your other stuff rescue_from ActiveRecord::RecordNotFound do |exception| redirect_to root_path, 404, alert: I18n.t("errors.record...

Database configuration of a rails project lies in a file config/database.yml. If you create a project using rails new command and don't specify a database engine to be used then rails uses sqlite as the default database. A typical database.yml file with default configuration will look similar to fol...

Callbacks offer a way to extend the functionality of a function (or method) without changing its code. This approach is often used in modules (libraries / plugins), the code of which is not supposed to be changed. Suppose we have written the following function, calculating the sum of a given array ...

Testing your Active Record models through your command line interface is simple. Navigate to the app directory in your terminal and type in rails console to start the Rails console. From here, you can run active record methods on your database. For example, if you had a database schema with a User...

Consumable Managed Products are products that can be bought multiple times such as in-game currency, game lives, power-ups, etc. In this example, we are going to implement 4 different consumable managed products "item1", "item2", "item3", "item4". Steps in...

console.count([obj]) places a counter on the object's value provided as argument. Each time this method is invoked, the counter is increased (with the exception of the empty string ''). A label together with a number is displayed in the debugging console according to the following format: [label]: ...

Debug.log's second argument is always returned, so you could write code like the following and it would just work: update : Msg -> Model -> (Model, Cmd Msg) update msg model = case Debug.log "The Message" msg of Something -> ... Replacing case msg o...

There are a few libraries for unit testing in Common Lisp FiveAM Prove, with a few unique features like extensive test reporters, colored output, report of test duration and asdf integration. Lisp-Unit2, similar to JUnit Fiasco, focusing on providing a good testing experience from the REPL. Su...

The following examples can be tested on https://ellie-app.com/m9vmQ8NcMc/0. import Html exposing (..) import Json.Decode payload = """ [ { "bark": true, "tag": "dog", "name": "Zap", "playful": true } , { "w...

Same conditions, multiple scripts If you need to inject multiple files with all other conditions being the same, for example to include a library, you can list all of them in the "js" array: "content_scripts" : [ { "js": ["library.js", "conten...

Under the attributes section you add the attributes to your model. This button is a plus located at the bottom of the section. You can add any attributes that are relevant to your app. You have several options of types to choose from ranging from Booleans to Dates and more. The Inspector panel also ...

To add a value to a Set, use the .add() method: mySet.add(5); If the value already exist in the set it will not be added again, as Sets contain unique values. Note that the .add() method returns the set itself, so you can chain add calls together: mySet.add(1).add(2).add(3);