Tutorial by Examples: p

Note: You need to know which data referenced by getReference() first before you can completely understand this example. There are three common method to get your data from Firebase Realtime Database: addValueEventListener() addListenerForSingleValueEvent() addChildEventListener() When w...

import sys from PyQt4 import QtGui def window(): app = QtGui.QApplication(sys.argv) w = QtGui.QWidget() b = QtGui.QLabel(w) b.setText("Hello World!") w.setGeometry(100,100,200,50) b.move(50,20) w.setWindowTitle("PyQt") w.show() sys.exit(app...

Throwable has two direct subclasses, Exception and Error. While it's possible to create a new class that extends Throwable directly, this is inadvisable as many applications assume only Exception and Error exist. More to the point there is no practical benefit to directly subclassing Throwable, as ...

A namespace can be given an alias (i.e., another name for the same namespace) using the namespace identifier = syntax. Members of the aliased namespace can be accessed by qualifying them with the name of the alias. In the following example, the nested namespace AReallyLongName::AnotherReallyLongNam...

Detailed instructions on getting apache-zookeeper set up or installed.

You can install ImageMagick from source or Binary. In case of Windows Binary Download executable binary file. And simply click on the appropriate version and it will launch itself and follow the wizard. You can type the following command to find out whether ImageMagick is successfully installed o...

This example demonstrate how to dynamically insert data into MySQL using Python Scrapy. You do not need to edit pipelines.py file for any project. This example can be used for all your project. Just yield you_data_dictionary from your Spider and inside pipelines.py a query will be created automat...

Enable pipelines in your settings.py ITEM_PIPELINES = { 'project_folder.pipelines.MyPipeline': 100 } Then write this code in items.py # -*- coding: utf-8 -*- from scrapy import Item, Field from collections import OrderedDict class DynamicItem(Item): def __setitem__(self, key, v...

Create a new Xamarin Forms app using PCL File -> New Solution -> Multiplatform App -> Xamarin Forms -> Forms App; Name the project as EffectsDemo Under the iOS project, add a new Effect class that inherits from PlatformEffect class and overrides the methods OnAttached, OnDetached and ...

Detailed instructions on getting mongodb-query set up or installed.

You may want to copy files from one place to another. In this example we'll teach you. You can use the command xcopy. The syntax is xcopy c:\From C:\To Example: @echo off xcopy C:\Folder\text.txt C:\User\Username\Desktop There are also switches you can use. If you want to view them open up co...

Calculating the power of a given number can be done recursively as well. Given a base number n and exponent e, we need to make sure to split the problem in chunks by decreasing the exponent e. Theoretical Example: 2² = 2x2 2³ = 2x2x2 or, 2³ = 2² x 2In there lies the secret of our recursive al...

This example shows a very basic example of how to utilize onCommand. I don't suggest processing your commands directly in onCommand, but this does the trick for this simple case. In this example we attempt to set the player's gamemode. The first thing we need to do is make sure that the sender isn...

Most examples show instantiating and holding a LazySingleton object until the owning application has terminated, even if that object is no longer needed by the application. A solution to this is to implement IDisposable and set the object instance to null as follows: public class LazySingleton : ID...

Creating a project in scala is very similar to creating one in java. Here is what the entry class should look like: package com.example.myplugin; //{$TopLevelDomain}.{$Domain}.{$PluginName} import org.bukkit.plugin.java.JavaPlugin import org.bukkit.command.CommandSender import org.bukkit.comma...

$model = Mage::getModel('catalog/product')->getCollection() Filter based on store: $mode->addStoreFilter($storeId) Filter based on product type: $mode->addAttributeToFilter('type_id', 'configurable') $mode->addAttributeToFilter('type_id', 'simple') Filter based on status: $m...

$rootId = Mage::app()->getStore($storeId)->getRootCategoryId(); $categories = Mage::getModel('catalog/category')->getCollection() ->addAttributeToSelect('*') ->addFieldToFilter('path', array('like'=> "1/$rootId/%")) ->addAttributeToFilter('level', 2...

SET FOREIGN_KEY_CHECKS = 0; TRUNCATE TABLE `catalog_product_bundle_option`; TRUNCATE TABLE `catalog_product_bundle_option_value`; TRUNCATE TABLE `catalog_product_bundle_selection`; TRUNCATE TABLE `catalog_product_entity_datetime`; TRUNCATE TABLE `catalog_product_entity_decimal`; TRUNCATE TAB...

Since a signal handler will be called by the kernel using the C calling convention, we must tell the compiler to use the C calling convention when compiling the function. volatile sig_atomic_t death_signal = 0; extern "C" void cleanup(int signum) { death_signal = signum; } int mai...

A C library header can usually be included into a C++ program, since most declarations are valid in both C and C++. For example, consider the following foo.h: typedef struct Foo { int bar; } Foo; Foo make_foo(int); The definition of make_foo is separately compiled and distributed with the...