Tutorial by Examples: d

The ?= operator is an extension that behaves like =, except that the assignment only occurs if the variable is not already set. x = hello x ?= world # $(x) will yield "hello"

The += operator is a common extension that adds the specified content to the end of the variable, separated by a space. x = hello x += world Variable references in the right-hand side will be expanded if and only if the original variable was defined as a simply-expanded variable.

This is such a common requirement in iOS development, and it was always something that had to be done purely in code (or using images - yuck!). Now it's incredibly easy to preview his kind of thing in Interface Builder, there's absolutely no excuse for not using it. Here's the code:- import UIKit ...

This tutorial assumes you already have a working OpenGL environment with all necessary libraries and headers available. #include <GL\glew.h> //Include GLEW for function-pointers etc. #include <GLFW\GLFW3.h> //Include GLFW for windows, context etc. //Impor...

glfwDefaultWindowHints(); glfwWindowHint(GLFW_RESIZABLE, GL_FALSE); glfwWindowHint(GLFW_SAMPLES, 4); glfwWindowHint(GLFW_VISIBLE, GL_FALSE); //Window hints are used to manipulate the behavior of later created windows //As the name suggests, they are only hints, not hard constraints, which mea...

File Structure: pom.xml src/test/java/PlayStoreAutomation.java Launch command: mvn test -Dtest=PlayStoreAutomation PlayStoreAutomation.java import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; import io.appium.java_client.android.AndroidDriver; import i...

The below example widget demonstrates how to format individual cells of a TreeView column conditionally, depending on value of the field in the particular cell. If value of field is negative, then it'll be displayed in red color and minus symbol will be hidden, otherwise it'll be displayed in normal...

The sequence for an error is usually: error is triggered by looking up the error name in errordict and executing this procedure. the errordict procedure calls signalerror, passing it the error name. signalerror takes snapshots of the stacks, saving the snapshots in $error, and then calls stop. ...

The documentation for docker events provides details, but when debugging it may be useful to launch a container and be notified immediately of any related event: docker run... & docker events --filter 'container=$(docker ps -lq)' In docker ps -lq, the l stands for last, and the q for quiet. Th...

For templated code it is often useful to verify that for function attributes (e.g. @nogc are inferred correctly. To ensure this for a specific test and thus type the entire unittest can be annotated @safe @nogc pure nothrow unittest { import std.math; assert(exp(0) == 1); assert(l...

In the scenario that a controller throws an exception, we can define exception handler methods to build and return specific responses. It is important to note that the defined exception handlers within the given controller will only apply to exceptions that occur within that controller. @Controller...

We're going to build an application that stores POJOs in a database. The application uses Spring Data JPA to store and retrieve data in a relational database. Its most compelling feature is the ability to create repository implementations automatically, at runtime, from a repository interface. Main...

Hash function h() is an arbitrary function which mapped data x ∈ X of arbitrary size to value y ∈ Y of fixed size: y = h(x). Good hash functions have follows restrictions: hash functions behave likes uniform distribution hash functions is deterministic. h(x) should always return the same v...

The replica set is a group of mongod instances that maintain the same data set. This example shows how to configure a replica set with three instances on the same server. Creating data folders mkdir /srv/mongodb/data/rs0-0 mkdir /srv/mongodb/data/rs0-1 mkdir /srv/mongodb/data/rs0-2 Starting ...

We add three records to our collection test as: > db.test.insert({"key":"value1","key2":"Val2","key3":"val3"}) WriteResult({ "nInserted" : 1 }) > db.test.insert({"key":"value2","key2":"V...

Loading custom fonts can be lead to a bad performance. I highly recommend to use this little helper which saves/loads your already used fonts into a Hashtable. public class TypefaceUtils { private static final Hashtable<String, Typeface> sTypeFaces = new Hashtable<>(); /** * Get...

There is no direct equivalent binding in KnockoutJS. However, since hiding is just the opposite of showing, we can just invert the example for Knockout's ngShow equivalent. <p ng-hide="SomeScopeProperty">This is conditionally shown.</p> KnockoutJS equivalent: <p data-bi...

build.gradle repositories { maven { url 'http://4thline.org/m2' } } dependencies { // Cling compile 'org.fourthline.cling:cling-support:2.1.0' //Other dependencies required by Cling compile 'org.eclipse.jetty:jetty-server:8.1.18.v20150929' compile 'org.eclipse.jetty:jetty-servlet:8....

Say, you have a dataset consisting of names and email addresses. Now in another dataset, you just have the email address and wish to find the appropriate first name that belongs to that email address. The MATCH function returns the appropriate row the email is at, and the INDEX function selects i...

As an alternative to using Html.ActionLink to generate links in a view, you can use Html.RouteLink To make use of this feature, you need to configure a route, for example: public static void RegisterRoutes(RouteCollection routes) { routes.MapRoute( "SearchResults", "{...