Tutorial by Examples: er

Up and running with Flower

Flower is a web based tool to monitor Celery. To install Flower, we can use pip as follows: pip install flower To run Flower for proj: celery -A proj flower Now, flower is accessible in: http://localhost:5555

celery • Celery monitoring with Flower

Rendering components

There are two options to render components on server: renderToString and renderToStaticMarkup. renderToString This will render React components to HTML on server. This function will also add data-react- properties to HTML elements so React on client won't have to render elements again. import { r...

React • Introduction to Server-Side Rendering

Observer pattern

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 ...

C++ • Design pattern implementation in C++

Simple React Component

We want to be able to compile below component and render it in our webpage Filename: src/index.jsx import React from 'react'; import ReactDOM from 'react-dom'; class ToDo extends React.Component { render() { return (<div>I am working</div>); } } ReactDOM.re...

React • Setting Up React Environment

HTML file to use react component

Setup a simple html file in the root of the project directory Filename: index.html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> </head> <body> <div id="App"></div> ...

React • Setting Up React Environment

Adapter Pattern

Convert the interface of a class into another interface clients expect. Adapter (or Wrapper) lets classes work together that couldn't otherwise because of incompatible interfaces. Adapter pattern's motivation is that we can reuse existing software if we can modify the interface. Adapter pattern...

C++ • Design pattern implementation in C++

Using gen_server behavior

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...

Erlang Language • gen_server behavior

How to allow reading specific item from group, but prevent listing group members

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...

firebase • Database Rules

Pointer Operations

There are two operators for pointers: Address-of operator (&): Returns the memory address of its operand. Contents-of (Dereference) operator(*): Returns the value of the variable located at the address specified by its operator. int var = 20; int *ptr; ptr = &var; cout << var &...

C++ • Pointers

Phaser environment setup (Asp.Net MVC5 - Typescript - Visual Studio 2015)

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...

phaser-framework • Working with TypeScript

If operator

9.0 If(condition > value, "True", "False") We can use the If operator instead of If...Then...Else..End If statement blocks. Consider the following example: If 10 > 9 Then MsgBox("True") Else MsgBox("False") End If is the same as M...

Visual Basic .NET Language • Conditions

B - Rendering the basic google map

Getting You Browser Ready - Polyfill it Create a new landing page for our element, at index.html. Include polyfills for a custom element to work.Also import the custom element g-map, which we registered with Polymer. Note: Webcomponents, are the necessary polyfill for browser support. Polym...

polymer • Google Map Mark With Built in Cache

The Complete Custom Google Map Polymer With In Built Cache

polymer • Google Map Mark With Built in Cache

Deployment friendly Project with Docker support.

The default Django project template is fine but once you get to deploy your code and for example devops put their hands on the project things get messy. What you can do is separate your source code from the rest that is required to be in your repository. You can find a usable Django project templ...

Django • Getting started with Django

Adding mouse listeners

Sometimes, you want to add listeners on particular events not natively provided by the components, in particular mouse events. To do so, you will have to add them by yourself using an EventTrigger component : using UnityEngine; using UnityEngine.EventSystems; [RequireComponent(typeof( EventTrig...

unity3d • User Interface System (UI)

Loading external Class files into script.

Dim classFile : classFile = "carClass.vbs" Dim fsObj : Set fsObj = CreateObject("Scripting.FileSystemObject") Dim vbsFile : Set vbsFile = fsObj.OpenTextFile(classFile, 1, False) Dim myFunctionsStr : myFunctionsStr = vbsFile.ReadAll vbsFile.Close Set vbsFile = Nothing Set fs...

vbscript • Using Classes

Service Account Authentcation Vb.net

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 ...

google-analytics-api • Authentication

Binding std::function to a different callable types

/* * This example show some ways of using std::function to call * a) C-like function * b) class-member function * c) operator() * d) lambda function * * Function call can be made: * a) with right arguments * b) argumens with different order, types and count */ #include &lt...

C++ • std::function: To wrap any element that is callable

Screen Manager

In the following example there are 2 Screens: SettingsScreen and MenuScreen Using the first button, on the current screen will change your screen to the other screen. Here is the code: from kivy.app import App from kivy.lang import Builder from kivy.uix.screenmanager import ScreenManager, Scr...

kivy • Using the Screen Manager

Asynchronous Controller

public async Task<actionresult> Index() { return View("View", await db.UserMasers.ToListAsync()); }

asp.net-mvc-5 • Asynchronous Controller in MVC 5