Tutorial by Examples: g

The window.postMessage() method together with its relative event handler window.onmessage can be safely used to enable cross-origin communication. The postMessage() method of the target window can be called to send a message to another window, which will be able to intercept it with its onmessage e...

&& has precedence over ||, this means that parentheses are placed to evaluate what would be evaluated together. c++ uses short-circuit evaluation in && and || to not do unnecessary executions. If the left hand side of || returns true the right hand side does not need to be evaluate...

To execute a Redis command using Jedis, you make method calls against the Jedis object you created from the pool. Jedis exposes Redis commands as method calls, some example are: - String get(String key) - Long geoadd(String key, double longitude, double latitude, String member) - List<String...

Many C++ libraries use enums and return/receive data using vectors that contain enums. As C enums are not Objective-C objects, Objective-C collections cannot be used directly with C enums. The example below deals with this by using a combination of an NSArray and generics and a wrapper object for th...

cljs-time gives us option to add/subtract date-times to other date-times. The date times added subtracted should be in form of days, months, years, hours etc. (require '[clj-time.core :as t]) (def example-date (t/date-time 2016 1 1)) ;; #<DateTime 2016-01-01T00:00:00.000Z> ;; Addition ...

Service that is used for communication: import { Injectable } from '@angular/core'; import { Subject } from 'rxjs/Subject'; @Injectable() export class ComponentCommunicationService { private componentChangeSource = new Subject(); private newDateCreationSource = new Subject<Date&...

Sometimes you need to create your own Event, one that other plugins can listen to (Vault, among other plugins, does this) and even cancel. Bukkit's Event API allows this to be possible. All you need to do is make a new class, have it extend Event, add the handlers and the attributes your event needs...

So first we will create rails project and setup device create a rails application rails new devise_example now add devise to gem list you can find a file named 'Gemfile' at the root of rails project Then run bundle install Next, you need to run the generator: rails generate devise:insta...

MultiTrigger is not needed frequently but there are some situations where it is very handy. MultiTrigger behaves similarly to Trigger or DataTrigger but it has multiple conditions. All the conditions must be true for a Setters to fire. Here is a simple example: <!-- Text field needs to be initia...

To create our own MessageBox control simply follow the guide below... Open up your instance of Visual Studio (VS 2008/2010/2012/2015/2017) Go to the toolbar at the top and click File -> New Project --> Windows Forms Application --> Give the project a name and then click ok. O...

public static FontFamily GetResourceFontFamily(byte[] fontbytes) { PrivateFontCollection pfc = new PrivateFontCollection(); IntPtr fontMemPointer = Marshal.AllocCoTaskMem(fontbytes.Length); Marshal.Copy(fontbytes, 0, fontMemPointer, fontbytes.Length); pfc.AddMemoryFont(fontMemPo...

public static class Res { /// <summary> /// URL: https://www.behance.net/gallery/2846011/Manteka /// </summary> public static FontFamily Maneteke = GetResourceFontFamily(Properties.Resources.manteka); public static FontFamily GetRes...

Signals are only available to GObject classes. They can only be public, which means that any part of the code can connect handlers and trigger them. public class Emitter : Object { // A signal is declared like a method, // but with the signal keyword. public signal void my_signal ();...

You can write detailed signals with the [Signal (detailed = true)] attribute. public class Emitter : Object { [Signal (detailed = true)] public signal void detailed_signal (); public void emit_with_detail (string detail) { this.detailed_signal[detail] (); } } void...

You can declare a UIFont as follows: var font: UIFont! UIFont has more init() methods: UIFont.init(descriptor: UIFontDescriptor, size: CGFloat) UIFont.init(name: String, size: CGFloat) Therefore, you can initialize a UIFont like this: let font = UIFont(name: "Helvetica Neue", s...

To change a label's text font, you need to access its font property: label.font = UIFont(name:"Helvetica Neue", size: 15) The code above will change the font of the label to Helvetica Neue, size 15. Beware that you must spell the font name correctly, otherwise it will throw this error,...

Used for the RAII style acquiring of try locks, timed try locks and recursive locks. std::unique_lock allows for exclusive ownership of mutexes. std::shared_lock allows for shared ownership of mutexes. Several threads can hold std::shared_locks on a std::shared_mutex. Available from C++ 14. std:...

std::call_once ensures execution of a function exactly once by competing threads. It throws std::system_error in case it cannot complete its task. Used in conjunction with std::once_flag. #include <mutex> #include <iostream> std::once_flag flag; void do_something(){ std::ca...

Kernel manages operating system resources. User program can only access to those resources by making system calls to the kernel. System call is similar to an API of kernel, which in term, runs kernel tasks your program needs. str = "something" // run on user space x = x + 1 // run on use...

Disabling calculation of the worksheet can decrease running time of the macro significantly. Moreover, disabling events, screen updating and page breaks would be beneficial. Following Sub can be used in any macro for this purpose. Sub OptimizeVBA(isOn As Boolean) Application.Calculation = IIf(...