Tutorial by Examples: p

Partially update the view

Makes an ajax request and updates only part of the view. Bean.java @ManagedBean @ViewScoped public class Bean { public Date getCurrentDate() { return new Date(); } } sample.xhtml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://xmlns...

Send form parts and listen to the request

Makes a request only sending part of the form. The text1 value is set, but not text2, as the listener states. Bean.java @ManagedBean @ViewScoped public class Bean { private String text1; private String text2; public String getText1() { return text1; } pu...

Ajax on javascript event

The date is updated whenever user types on the input field: Bean.java @ManagedBean @ViewScoped public class Bean { public Date getCurrentDate(){ return new Date(); } } sample.xhtml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://x...

Automatically processing data received from a serial port

Some devices connected through a serial port send data to your program at a constant rate (streaming data) or send data at unpredictable intervals. You can configure the serial port to execute a function automatically to handle data whenever it arrives. This is called the "callback function&quo...

Local Type Inference

Scala has a powerful type-inference mechanism built-in to the language. This mechanism is termed as 'Local Type Inference': val i = 1 + 2 // the type of i is Int val s = "I am a String" // the type of s is String def squared(x : Int) = x*x // the return type ...

Type Inference And Generics

The Scala compiler can also deduce type parameters when polymorphic methods are called, or when generic classes are instantiated: case class InferedPair[A, B](a: A, b: B) val pairFirstInst = InferedPair("Husband", "Wife") //type is InferedPair[String, String] // Equiv...

Splitting a string into a list

To split strings, Guava introduces the Splitter class. Why not use Java's splitting capabilities? As a rule, Guava does not duplicate functionality that is readily available in Java. Why then do we need an additional Splitter class? Do the split methods in Java's String class not provide us with a...

Basics: initialize the SPI and a chip select pin, and perform a 1-byte transfer

#include <SPI.h> #define CSPIN 1 void setup() { pinMode(CSPIN, OUTPUT); // init chip select pin as an output digitalWrite(CSPIN, 1); // most slaves interpret a high level on CS as "deasserted" SPI.begin(); SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MO...

OneGet and packet managers

OneGet was originally a product from the Open Source Technology Center at Microsoft. Not only is it inspired by open-source Linux package managers, OneGet itself is also open source. It's now part of PowerShell As opposed to Unix based package managers (such as apt-get, yum, or dpkg), Windows allow...

atomics and operators

Atomic variables can be accessed concurrently between different threads without creating race conditions. /* a global static variable that is visible by all threads */ static unsigned _Atomic active = ATOMIC_VAR_INIT(0); int myThread(void* a) { ++active; // increment active race fr...

Set password for admin

Here is a workaround to temporary reset your password for your account. Login to your hosting panel and use the database tool that is available (probably PHPmyAdmin). Load the appropriate database and then go to the jos_users table. (The database prefix might be different for your case). ...

Using Hierarchy Custom Settings To Disable Apex Code

Explanation In this example a simple Trigger has been created to change the Close Date of an Opportunity, that's about to be inserted or updated, to a date 10 days in the future. The Apex Controller custom setting's checkbox field enables the code to be disabled at the user / profile / org level. ...

Obtain an Instance of HTTP Request

To obtain an instance of an HTTP Request, class Illuminate\Http\Request need to be type hint either in the constructor or the method of the controller. Example code: <?php namespace App\Http\Controllers; /* Here how we illuminate the request class in controller */ use Illuminate\Http\Re...

Request Instance with other Parameters from routes in controller method

Sometimes we need to accept route params as well as access the HTTP Request params. We can still type hint the Requests class in laravel controller and achieve that as explained below E.g. We have a route that update a certain post like this (passing post id i route ) Route::put('post/{id}', 'Post...

Representation of signed integers

Each signed integer type may be represented in any one of three formats; it is implementation-defined which one is used. The implementation in use for any given signed integer type at least as wide as int can be determined at runtime from the two lowest-order bits of the representation of value -1 ...

Using scoped services during application startup / Database Seeding

Resolving scoped services during application startup can be difficult, because there is no request and hence no scoped service. Resolving a scoped service during application startup via app.ApplicationServices.GetService<AppDbContext>() can cause issues, because it will be created in the sc...

Installation or Setup

Visual Studio 2013 can be downloaded here The setup is pretty easy.Select features you need and select the disk to install VS13 on.Click install and wait for it to finish.

Online Compilers

Various websites provide online access to C++ compilers. Online compiler's feature set vary significantly from site to site, but usually they allow to do the following: Paste your code into a web form in the browser. Select some compiler options and compile the code. Collect compiler and/or pro...

Scraping using BeautifulSoup4

from bs4 import BeautifulSoup import requests # Use the requests module to obtain a page res = requests.get('https://www.codechef.com/problems/easy') # Create a BeautifulSoup object page = BeautifulSoup(res.text, 'lxml') # the text field contains the source of the page # Now use a CSS ...

Java Example

A great existing example of the Adapter pattern can be found in the SWT MouseListener and MouseAdapter classes. The MouseListener interface looks as follows: public interface MouseListener extends SWTEventListener { public void mouseDoubleClick(MouseEvent e); public void mouseDown(MouseE...

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