Tutorial by Examples: v

Observer Pattern's intent is to define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. The subject and observers define the one-to-many relationship. The observers are dependent on the subject such that when ...

A gen_server is a specific finite state machine working like a server. gen_server can handle different type of event: synchronous request with handle_call asynchronous request with handle_cast other message (not defined in OTP specification) with handle_info Synchronous and asynchronous mess...

This source code create a simple key/value store service based on map Erlang datastructure. Firstly, we need to define all information concerning our gen_server: -module(cache). -behaviour(gen_server). % our API -export([start_link/0]). -export([get/1, put/2, state/0, delete/1, stop/0]). %...

In the Garbage collection example, we implied that Java solves the problem of memory leaks. This is not actually true. A Java program can leak memory, though the causes of the leaks are rather different. Reachable objects can leak Consider the following naive stack implementation. public class ...

It is common practice to create groups of items by creating simple value nodes with item ID as key. For example, we can add a user to the group "administrators" by creating a node at /administrators/$user_id with a value true. We don't want anyone to know who administrators are, for securi...

function downloadCsv() { var blob = new Blob([csvString]); if (window.navigator.msSaveOrOpenBlob){ window.navigator.msSaveBlob(blob, "filename.csv"); } else { var a = window.document.createElement("a"); a.href = window.URL.createObjectURL(blob, { ...

Create a new ASP.Net Project: Select the empty template: Add two new folders: App and Scripts in the root folder: Add npm configuration file in the root folder: { "version": "1.0.0", "name": "phaser.js.environment.setup", "priva...

Let's create a very simple view to respond a "Hello World" template in html format. To do that go to my_project/my_app/views.py (Here we are housing our view functions) and add the following view: from django.http import HttpResponse def hello_world(request): html = "&lt...

Sample uses Install-Package Google.Apis.AnalyticsReporting.v4 Public Shared Function getServiceInitializer() As BaseClientService Dim serviceAccountCredentialFilePath = "Path to Json service account key file" REM from Google Developers console Dim myKeyEMail ...

Typescript supports costant enumerables, declared through const enum. This is usually just syntax sugar as the costant enums are inlined in compiled JavaScript. For instance the following code const enum Tristate { True, False, Unknown } var something = Tristate.True; compil...

You can use a TStringList to store Key-Value pairs. This can be useful if you want to store settings, for example. A settings consists of a Key (The Identifier of the setting) and the value. Each Key-Value pair is stored in one line of the StringList in Key=Value format. procedure Demo(const FileN...

You can use plugman command to install/uninstall custom cordova plugins. To install plugman npm install -g plugman Install plugin command syntax: plugman <install|uninstall> --platform <ios|android|blackberry10|wp8> --project <directory> --plugin <name|url|path> Exa...

Below is an example of Gstreamer pipeline embedded in a simple gtk window. When run, a small window should appear like this: import gi gi.require_version('Gtk', '3.0') gi.require_version('Gst', '1.0') from gi.repository import Gtk, Gst Gst.init(None) Gst.init_check(None) class GstWidg...

There are different variable types for different purposes. In Visual Basic 6 the following variable types are available: Array Boolean Byte Currency Date Double Integer Long Single String Variant You declare a variable by using the Dim keyword: Dim RandomNumber As Integer If you ...

update <SCHEMA_NAME>.<TABLE_NAME_1> AS A SET <COLUMN_1> = True FROM <SCHEMA_NAME>.<TABLE_NAME_2> AS B WHERE A.<COLUMN_2> = B.<COLUMN_2> AND A.<COLUMN_3> = B.<COLUMN_3>

Conditions: package should be at least installed. If not loaded in the current session, not a problem. ## Checking package version which was installed at past or ## installed currently but not loaded in the current session packageVersion("seqinr") # [1] ‘3.3.3’ packageVer...

To check the list of loaded packages search() OR (.packages())

Model With EF Core, data access is performed using a model. A model is made up of entity classes and a derived context that represents a session with the database, allowing you to query and save data. You can generate a model from an existing database, hand code a model to match your database, or ...

<?php echo get_field('my_field_name', 123); ?> This will echo the value of "my_field_name" from the post with 123 as its ID.

<?php echo get_field('my_field_name', 'option'); ?> This will echo the value of "my_field_name" from the options page created via ACF.