Tutorial by Examples

void DispatchToMainThread(std::function<void()> callback) { // any thread QTimer* timer = new QTimer(); timer->moveToThread(qApp->thread()); timer->setSingleShot(true); QObject::connect(timer, &QTimer::timeout, [=]() { // main thread ...

Q_OBJECT macro appears in private section of a class. Q_OBJECT requires the class to be subclass of QObject. This macro is necessary for the class to declare its signals/slots and to use Qt meta-object system. If Meta Object Compiler (MOC) finds class with Q_OBJECT, it processes it and generates C+...

Multiplicity in Entity Relationships Multiplicities are of the following types: One-to-one: Each entity instance is related to a single instance of another entity. One-to-many: An entity instance can be related to multiple instances of the other entities. Many-to-one: multiple instances of an ...

When mapping many-to-many relationships in JPA, configuration for the table used for the joining foreign-keys can be provided using the @JoinTable annotation: @Entity public class EntityA { @Id @Column(name="id") private long id; [...] @ManyToMany @JoinTable(name=...

Usually you'd want to create a stack of services to form a replicated and orchestrated application. A typical modern web application consists of a database, api, frontend and reverse proxy. Persistence Database needs persistence, so we need some filesystem which is shared across all the nodes in ...

insert into schema.table (field1, field2) select 'Static Value', foreignField from schema.otherTable;

Our UserProfile class Create a UserProfile model class with the relationship of OneToOne to the default User model: from django.db import models from django.contrib.auth.models import User from django.db.models.signals import post_save class UserProfile(models.Model): user = models.OneTo...

npm install sqlite3 --build-from-source --runtime=node-webkit --target_arch=ia32 --target= target is important. ex:0.16.1 npm rebuild Create a folder for sqlite db. Remember sequalize.sync();

Quick installation guide: Download and unzip the PrestaShop package to a directory in you web hosting. Create a database for PrestaShop. Open a browser to the url where are PrestaShop files. Follow the screen istructions. Delete the /install directory and rename /admin directory. Official ...

Given a non-empty cv::Mat img of some size, we can fill it to a solid color in several ways: img = cv::Scalar(blueVal,greenVal,redVal); or, the more general, mask supporting, cv::Mat::setTo(): img.setTo(cv::Scalar(blueVal,greenVal,redVal)); If you are using the older OpenCV C API with IplIma...

def count = 0 nonmemoized = { long n -> println "nonmemoized: $n"; count++ } nonmemoized(1) nonmemoized(2) nonmemoized(2) nonmemoized(1) assert count == 4 def mcount = 0 memoized = { long n -> println "memoized: $n"; mcount++ }.memoize() memoized(1) me...

Right click on your project folder/name and create new area and name it. In mvc internet/empty/basic application a folder with the name of the area will be created,which will contain three different folders named controller , model and views and a class file called "areanameAreaRegistration.c...

In your App_start folder open routeconfig.cs and do this routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, ...

Create a new controller foreg ControllerName: "Home", ActionresultName :"Index" open AreaRegistraion.cs and add the controller name and action name to be rerouted to context.MapRoute( "nameofarea_default", "nameofarea/{controller}/...

When using html5Mode([mode]) it is necessary that: You specify the base URL for the application with a <base href=""> in the head of your index.html. It is important that the base tag comes before any tags with url requests. Otherwise, this might result in this error - &quo...

using System.Diagnostics.Contracts; public int DivideNumbers(int numerator, int denominator) { Contract.Requires(denominator != 0); return numerator / denominator; }

using System.Diagnostics.Contracts; public int DivideNumbers(int numerator, int denominator) { Contract.Requires<ArgumentOutOfRangeException>(denominator != 0); return numerator / denominator; }

You can place action filters at three possible levels: Global Controller Action Placing a filter globally means it will execute on requests to any route. Placing one on a controller makes it execute on requests to any action in that controller. Placing one on an action means it runs with the...

$ for shell in ash bash dash ksh ksh93 zsh; do > $shell -c "echo '\\\\'$shell'\\\\'" > done \\ash\\ \\bash\\ \dash\ \pdksh\ \\ksh93\\ \zsh\ 'echo' can only be used consistently, across implementations, if its arguments do not contain any backslashes (reverse-solidi...

Hibernate is an implementation of the JPA standard. As such, everything said there is also true for Hibernate. Hibernate has some extensions to JPA. Also, the way to set up a JPA provider is provider-specific. This documentation section should only contain what is specific to Hibernate.