If you want to create and send signals in your own code (for example, if you are writing an extension), create a new Signal instance and call send when the subscribers should be notified. Signals are created using a Namespace.
from flask import current_app
from flask.signals import Namespace
n...
First, references will be added to the CLR assemblies that will be used.
import clr
clr.AddReference('System.Windows.Forms')
Next the names we will use are imported.
from System.Windows.Forms import Application, Form
A class will be created for the Hello World form using Form as its subclas...
Components are simply instances that implement the Ashley component class.
import com.badlogic.ashley.core.Component;
import com.badlogic.ashley.core.ComponentMapper;
public class Position implements Component {
public static final ComponentMapper<Position> Map =
...
Entity systems are how you perform functional operations on sets of entities. Components should typically not have logic associated with them that involves awareness of data or state of other component instances, as that is the job of an entity system. An entity system can not be registered to mor...
Closures are inline anonymous methods that have the ability to use Parent method variables and other anonymous methods which are defined in the parent's scope.
In essence, a closure is a block of code which can be executed at a
later time, but which maintains the environment in which it was firs...
The IEnumerable<T> interface has a single method, GetEnumerator(), which returns an IEnumerator<T>.
While the yield keyword can be used to directly create an IEnumerable<T>, it can also be used in exactly the same way to create an IEnumerator<T>. The only thing that changes ...
When an object implements the IDisposable interface, it can be created within the using syntax:
using (var foo = new Foo())
{
// do foo stuff
} // when it reaches here foo.Dispose() will get called
public class Foo : IDisposable
{
public void Dispose()
{
Console.WriteL...
This will create a timer to call the doSomething method on self in 5 seconds.
Swift
let timer = NSTimer.scheduledTimerWithTimeInterval(5,
target: self,
selector: Selector(doSomething()),
userInfo: nil,
...
Swift
timer.fire()
Objective-C
[timer fire];
Calling the fire method causes an NSTimer to perform the task it would have usually performed on a schedule.
In a non-repeating timer, this will automatically invalidate the timer. That is, calling fire before the time interval is up will result ...
Swift
timer.invalidate()
Objective-C
[timer invalidate];
This will stop the timer from firing. Must be called from the thread the timer was created in, see Apple's notes:
You must send this message from the thread on which the timer was installed. If you send this message from another thr...
5.1
JavaScript does not directly support enumerators but the functionality of an enum can be mimicked.
// Prevent the enum from being changed
const TestEnum = Object.freeze({
One:1,
Two:2,
Three:3
});
// Define a variable with a value from the enum
var x = TestEnum.Two;
// Prin...
For example, if t1 is currently not an InnoDB table, this statement changes its storage engine to InnoDB:
ALTER TABLE t1 ENGINE = InnoDB;
If the table is already InnoDB, this will rebuild the table and its indexes and have an effect similar to OPTIMIZE TABLE. You may gain some disk space improv...
Like lists and tuples, you can include a trailing comma in your dictionary.
role = {"By day": "A typical programmer",
"By night": "Still a typical programmer", }
PEP 8 dictates that you should leave a space between the trailing comma and the closi...
There are three kinds of numeric RangeFields in Python. IntegerField, BigIntegerField, and FloatField. They convert to psycopg2 NumericRanges, but accept input as native Python tuples. The lower bound is included and the upper bound is excluded.
class Book(models.Model):
name = CharField(max_l...
It's simpler and easier to input values as a Python tuple instead of a NumericRange.
Book.objects.create(name='Pro Git', ratings_range=(5, 5))
Alternative method with NumericRange:
Book.objects.create(name='Pro Git', ratings_range=NumericRange(5, 5))
This query gets all books with ratings greater than or equal to zero and less than six.
all_books = Book.objects.filter(ratings_range_contained_by=(0, 6))
