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...
Sometimes it might be necessary to manually promisify a callback function. This could be for a case where the callback does not follow the standard error-first format or if additional logic is needed to promisify:
Example with fs.exists(path, callback):
var fs = require('fs');
var existsAsync =...
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
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...
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.*
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 ...
First we need to reference the Styles we want to use.
<link rel="stylesheet" href="[file path]/kendo.common.min.css" />
<link rel="stylesheet" href="[file path]/kendo.[Theme].min.css" />
Now most of the controls use the [Theme], given in the a...
It is often useful for debugging purposes to find the root cause of an error. In order to examine an error value that implements std::error::Error:
use std::error::Error;
let orig_error = call_returning_error();
// Use an Option<&Error>. This is the return type of Error.cause().
le...
You can use an environment filter to change the author of commits. Just modify and export $GIT_AUTHOR_NAME in the script to change who authored the commit.
Create a file filter.sh with contents like so:
if [ "$GIT_AUTHOR_NAME" = "Author to Change From" ]
then
export GIT_A...
In Python 3, PEP 404 changes the way imports work from Python 2. Implicit relative imports are no longer allowed in packages and from ... import * imports are only allowed in module level code.
To achieve Python 3 behavior in Python 2:
the absolute imports feature can be enabled with from __futu...
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...
To forbid null values in your table columns, add the :null parameter to your migration, like this:
class AddPriceToProducts < ActiveRecord::Migration
def change
add_column :products, :float, null: false
end
end
You may want to nest cached fragments inside other cached fragments. This is called Russian doll caching.
The advantage of Russian doll caching is that if a single product is updated, all the other inner fragments can be reused when regenerating the outer fragment.
As explained in the previous sec...
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...
Provided an App.GoogleMap coffee script class, the google map can be initialized like this:
# app/assets/javascripts/google_maps.js.coffee
# ...
class App.GoogleMap
map_div: {}
map: {}
constructor: (map_div)->
@map_div = map_div
@init_map()
@reference_the_map_as_dat...
Provided an App.GoogleMap coffee script class and the marker information being stored in the data-address-fields attribute of the .google_map div, the map markers can be initialized on the map like this:
# app/assets/javascripts/google_maps.js.coffee
# ...
class App.GoogleMap
# ...
markers:...
Provided an App.GoogleMap coffee script class with the google.maps.Map stored as @map and the google.maps.Markers stored as @markers, the map can be auto-zoomed, i.e. adjusted that all markers are visible, like this:
on the map like this:
# app/assets/javascripts/google_maps.js.coffee
# ...
cla...
A has_many :through association is often used to set up a many-to-many connection with another model. This association indicates that the declaring model can be matched with zero or more instances of another model by proceeding through a third model.
For example, consider a medical practice where p...
A has_one :through association sets up a one-to-one connection with another model. This association indicates that the declaring model can be matched with one instance of another model by proceeding through a third model.
For example, if each supplier has one account, and each account is associated...
