Tutorial by Examples: le

Cloning a file using streams

This program illustrates how one can copy a file using readable and writable streams using the createReadStream(), and createWriteStream() functions provided by the file system module. //Require the file System module var fs = require('fs'); /* Create readable stream to file in current direc...

Node.js • Filesystem I/O

Produce a patch-compatible diff

Sometimes you just need a diff to apply using patch. The regular git --diff does not work. Try this instead: git diff --no-prefix > some_file.patch Then somewhere else you can reverse it: patch -p0 < some_file.patch

Git • Git Diff

Building your own modules

You can also reference an object to publicly export and continuously append methods to that object: const auth = module.exports = {} const config = require('../config') const request = require('request') auth.email = function (data, callback) { // Authenticate with an email address } au...

Node.js • Exporting and Consuming Modules

Completely uninstall Node.js on Mac OSX

In Terminal on your Mac operating system, enter the following 2 commands: lsbom -f -l -s -pf /var/db/receipts/org.nodejs.pkg.bom | while read f; do sudo rm /usr/local/${f}; done sudo rm -rf /usr/local/lib/node /usr/local/lib/node_modules /var/db/receipts/org.nodejs.*

Node.js • Uninstalling Node.js

Perfectly aligned buttons inside cards with flexbox

It's a regular pattern in design these days to vertically align call to actions inside its containing cards like this: This can be achieved using a special trick with flexbox HTML <div class="cards"> <div class="card"> <p>Lorem ipsum Magna proident ...

CSS • Flexible Box Layout (Flexbox)

Log for a range of lines within a file

$ git log -L 1,20:index.html commit 6a57fde739de66293231f6204cbd8b2feca3a869 Author: John Doe <[email protected]> Date: Tue Mar 22 16:33:42 2016 -0500 commit message diff --git a/index.html b/index.html --- a/index.html +++ b/index.html @@ -1,17 +1,20 @@ <!DOCTYPE HTML> ...

Git • Browsing the history

Implementation using RuntimeInitializeOnLoadMethodAttribute

Since Unity 5.2.5 it's possible to use RuntimeInitializeOnLoadMethodAttribute to execute initialization logic bypassing MonoBehaviour order of execution. It provides a way to create more clean and robust implementation: using UnityEngine; sealed class GameDirector : MonoBehaviour { // Beca...

unity3d • Singletons in Unity

Add the google maps javascript tag to the layout header

In order to have google maps work properly with turbolinks, add the javascript tag directly to the layout header rather than including it in a view. # app/views/layouts/my_layout.html.haml !!! %html{:lang => 'en'} %head - # ... = google_maps_api_script_tag The google_maps_api_s...

Ruby on Rails • Using GoogleMaps with Rails

Show addresses on a google map in the profile view

On the profile view, show the profile fields of a user or group in a list as well as the address fields on a google map. - # app/views/profiles/show.html.haml %h1 Contact Information .profile_fields = render @profile_fields .google_map{data: address_fields: @address_fields.to_json } The ap...

Ruby on Rails • Using GoogleMaps with Rails

Disable cache in Picasso

Picasso.with(context) .load(uri) .networkPolicy(NetworkPolicy.NO_CACHE) .memoryPolicy(MemoryPolicy.NO_CACHE) .placeholder(R.drawable.placeholder) .into(imageView);

Android • Picasso

Get locale from HTTP request

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...

Ruby on Rails • I18n - Internationalization

Cloning by implementing Clonable interface

Cloning an object by implementing the Cloneable interface. public class Sheep implements Cloneable { private String name; private int weight; public Sheep(String name, int weight) { this.name = name; this.weight = weight; } @Override public Ob...

Java Language • Object Cloning

Single file upload using Carrierwave

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...

Ruby on Rails • File Uploads

Nested model - multiple uploads

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...

Ruby on Rails • File Uploads

Generating a new mailer

To generate a new mailer, enter the following command rails generate mailer PostMailer This will generate a blank template file in app/mailers/post_mailer.rb named PostMailer class PostMailer < ApplicationMailer end Two layout files will also be generated for the email view, one for the...

Ruby on Rails • ActionMailer

Fat Model, Skinny Controller

“Fat Model, Skinny Controller” refers to how the M and C parts of MVC ideally work together. Namely, any non-response-related logic should go in the model, ideally in a nice, testable method. Meanwhile, the “skinny” controller is simply a nice interface between the view and model. In practice, this...

Ruby on Rails • Rails Best Practices

Google Sign In with Helper class

Add below to your build.gradle out of android tag: // Apply plug-in to app. apply plugin: 'com.google.gms.google-services' Add below helper class to your util package: /** * Created by Andy */ public class GoogleSignInHelper implements GoogleApiClient.OnConnectionFailedListener, ...

Android • Integrate Google Sign In

Generating a controller

Rails provides a lot of generators, for controllers too of course. You can generate a new controller by running this command in your app folder rails generate controller NAME [action action] [options] Note: You can also use rails g alias to invoke rails generate For example, to generate a cont...

Ruby on Rails • ActionController

Simple Legend

Suppose you have multiple lines in the same plot, each of a different color, and you wish to make a legend to tell what each line represents. You can do this by passing on a label to each of the lines when you call plot(), e.g., the following line will be labelled "My Line 1". ax.plot(...

matplotlib • Legends

Simple Callback Usage Examples

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 ...

JavaScript • Callbacks