Tutorial by Examples: t

When building a webserver with Express it's often required to serve a combination of dynamic content and static files. For example, you may have index.html and script.js which are static files kept in the file system. It is common to use folder named 'public' to have static files. In this case th...

A basic example of HTTP server. write following code in http_server.js file: var http = require('http'); var httpPort = 80; http.createServer(handler).listen(httpPort, start_callback); function handler(req, res) { var clientIP = req.connection.remoteAddress; var connectUsi...

a basic example for http client: write the follwing code in http_client.js file: var http = require('http'); var options = { hostname: '127.0.0.1', port: 80, path: '/', method: 'GET' }; var req = http.request(options, function(res) { console.log('STATUS: ' + res.statusCode)...

This program copies a file using readable and a writable stream with the pipe() function provided by the stream class // require the file system module var fs = require('fs'); /* Create readable stream to file in current directory named 'node.txt' Use utf8 encoding Read the data...

I/O in node is asynchronous, so interacting with the disk and network involves passing callbacks to functions. You might be tempted to write code that serves up a file from disk like this: var http = require('http'); var fs = require('fs'); var server = http.createServer(function (req, res) { ...

Multiple database cursors can be published from the same publication method by returning an array of cursors. The "children" cursors will be treated as joins and will not be reactive. Meteor.publish('USER_THREAD', function(postId) { let userId = this.userId; let comments = Comm...

Production deployments will vary in many ways, but a standard convention when deploying in production is to define an environment variable called NODE_ENV and set its value to "production". Runtime flags Any code running in your application (including external modules) can check the valu...

Example. It will be replacing the word email to a name in a text file index.txt with simple RegExp replace(/email/gim, 'name') var fs = require('fs'); fs.readFile('index.txt', 'utf-8', function(err, data) { if (err) throw err; var newValue = data.replace(/email/gim, 'name'); ...

app.js const readline = require('readline'); const fs = require('fs'); var file = 'path.to.file'; var linesCount = 0; var rl = readline.createInterface({ input: fs.createReadStream(file), output: process.stdout, terminal: false }); rl.on('line', function (line) { linesCo...

NodeJS executes the module only the first time you require it. Any further require functions will re-use the same Object, thus not executing the code in the module another time. Also Node caches the modules first time they are loaded using require. This reduces the number of file reads and helps to...

The following example shows how to merge two arrays into one associative array, where the key values will be the items of the first array, and the values will be from the second: $array_one = ['key1', 'key2', 'key3']; $array_two = ['value1', 'value2', 'value3']; $array_three = array_combine($ar...

If you want to hide a keyboard by tap outside of it, it's possible to use this hacky trick (works only with Objective-C): - (void)viewDidLoad { [super viewDidLoad]; // dismiss keyboard when tap outside a text field UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecogn...

In many environments, you have access to a global console object that contains some basic methods for communicating with standard output devices. Most commonly, this will be the browser's JavaScript console (see Chrome, Firefox, Safari, and Edge for more information). // At its simplest, you can 'l...

Hstore columns can be useful to store settings. They are available in PostgreSQL databases after you enabled the extension. class CreatePages < ActiveRecord::Migration[5.0] def change create_table :pages do |t| enable_extension 'hstore' unless extension_enabled?('hstore') t...

Get Focus Swift textField.becomeFirstResponder() Objective-C [textField becomeFirstResponder]; Resign Swift textField.resignFirstResponder() Objective-C [textField resignFirstResponder];

Vagrantfile Vagrant.configure("2") do |config| config.vm.box = "ubuntu/trusty64" config.vm.provision "ansible" do |ansible| ansible.playbook = "vagrant-playbook.yml" end end vagrant-playbook.yml --- - hosts: default tasks: - name: ...

vagrant up By default the box will be provisioned.

vagrant up --no-provision

F# allows functions to be added as "members" to types when they are defined (for example, Record Types). However F# also allows new instance members to be added to existing types - even ones declared elsewhere and in other .net languages. The following example adds a new instance method D...

F# allow existing types to be extended with new static functions. type System.String with static member EqualsCaseInsensitive (a, b) = String.Equals(a, b, StringComparison.OrdinalIgnoreCase) This new function can be invoked like this: let x = String.EqualsCaseInsensitive("abc", &...