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copy (select oid,relname from pg_class limit 5) to stdout;

In Kotlin, we can declare variable which can hold null reference. Suppose we have a nullable reference a, we can say "if a is not null, use it, otherwise use some non-null value x" var a: String? = "Nullable String Value" Now, a can be null. So when we need to access value o...

Prerequisites : ChromeDriver is downloaded Copy the following code into your class. public static void main(String[] args) { System.setProperty("webdriver.chrome.driver", "path of the exe file\\chromedriver.exe"); } If you're using linux, give the path to the ChromeDri...

Now we will apply a strided convolution to our previously described padded example and calculate the convolution where p = 1, s = 2 Previously when we used strides = 1, our slided window moved by 1 position, with strides = s it moves by s positions (you need to calculate s^2 elements less. But in...

Once you have discovered a desired BluetoothDevice object, you can connect to it by using its connectGatt() method which takes as parameters a Context object, a boolean indicating whether to automatically connect to the BLE device and a BluetoothGattCallback reference where connection events and cli...

Once you are connected to a Gatt Server, you're going to be interacting with it by writing and reading from the server's characteristics. To do this, first you have to discover what services are available on this server and which characteristics are avaiable in each service: @Override public voi...

You can request to be notified from the Gatt Server when the value of a characteristic has been changed: gatt.setCharacteristicNotification(characteristic, true); BluetoothGattDescriptor descriptor = characteristic.getDescriptor( UUID.fromString("00002902-0000-1000-8000-00805f9b34fb&quot...

You can use Bluetooth LE Advertising to broadcast data packages to all nearby devices without having to establish a connection first. Bear in mind that there's a strict limit of 31 bytes of advertisement data. Advertising your device is also the first step towards letting other users connect to you....

In order for your device to act as a peripheral, first you need to open a BluetoothGattServer and populate it with at least one BluetoothGattService and one BluetoothGattCharacteristic: BluetoothGattServer server=bluetoothManager.openGattServer(context, bluetoothGattServerCallback); BluetoothGat...

The default icon of the Date-Picker in the Extension Library from OpenNTF is nice but not sexy. You can change it to one of the cool "Font Awesome Icons". First, add a DatePicker component to your page: <xe:djDateTextBox id="datePickerComp" value="#{myDoc.myDateField}&q...

import UIKit struct Person { // Model let firstName: String let lastName: String } class GreetingViewController : UIViewController { // View + Controller var person: Person! let showGreetingButton = UIButton() let greetingLabel = UILabel() override func vie...

import UIKit struct Person { // Model let firstName: String let lastName: String } protocol GreetingView: class { func setGreeting(greeting: String) } protocol GreetingViewPresenter { init(view: GreetingView, person: Person) func showGreeting() } class Greetin...

import UIKit struct Person { // Model let firstName: String let lastName: String } protocol GreetingViewModelProtocol: class { var greeting: String? { get } var greetingDidChange: ((GreetingViewModelProtocol) -> ())? { get set } // function to call when greeting did cha...

The raycaster has an origin, where its ray starts, and a direction, where the ray goes. The origin of the raycaster is at the raycaster entity’s position. We can change the origin of the raycaster by setting the position component of the raycaster entity (or parent entities of the raycaster entity)...

We usually don’t want to test everything in the scene for intersections (e.g., for collisions or for clicks). Selective intersections are good for performance to limit the number of entities to test for intersection since intersection testing is an operation that will run over 60 times per second. ...

With any variadic function, the function must know how to interpret the variable arguments list. The “traditional” approach (exemplified by printf) is to specify number of arguments up front. However, this is not always a good idea: /* First argument specifies the number of parameters; the remaind...

Similar to aggregation methods also by the find() method you have the possibility to limit, skip, sort and count the results. Let say we have following collection: db.test.insertMany([ {name:"Any", age:"21", status:"busy"}, {name:"Tony", age:"...

import UIKit struct Person { // Entity (usually more complex e.g. NSManagedObject) let firstName: String let lastName: String } struct GreetingData { // Transport data structure (not Entity) let greeting: String let subject: String } protocol GreetingProvider { fu...

For Swift 3.1: In the first example one can see how you would intercept the user interacting with a textfield while writing. Similarly, there are methods in the UITextFieldDelegate that are called when a user has started and ended his interaction with a TextField. To be able to access these method...

This example shows how to achieve an effect similar to FaceTime were a view is attracted to point once it enters a particular region, in this case two regions a top and bottom. Swift class ViewController: UIViewController { lazy var dynamicAnimator: UIDynamicAnimator = { let ...