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Navigator is React Native's default navigator. A Navigator component manages a stack of route objects, and provides methods for managing that stack. <Navigator ref={(navigator) => { this.navigator = navigator }} initialRoute={{ id: 'route1', title: 'Route 1' }} renderScene={this.ren...

Redux is the most common state management library used with React-Native. The following example demonstrates how to use the fetch API and dispatch changes to your applications state reducer using redux-thunk. export const fetchRecipes = (action) => { return (dispatch, getState) => { f...

One of the major benefit of Fourier Transform is its ability to inverse back in to the Time Domain without losing information. Let us consider the same Signal we used in the previous example: A1=10; % Amplitude 1 A2=10; % Amplitude 2 w1=2*pi*0.2; % Angular f...

Let's say we have a simple table called person: CREATE TABLE person ( person_id BIGINT, name VARCHAR(255). age INT, city VARCHAR(255) ); The most basic insert involves inserting all values in the table: INSERT INTO person VALUES (1, 'john doe', 25, 'new york'); If you wa...

Beware that numbers can accidentally be converted to strings or NaN (Not a Number). JavaScript is loosely typed. A variable can contain different data types, and a variable can change its data type: var x = "Hello"; // typeof x is a string x = 5; // changes typeof x to...

GridViews allow commands to be sent from a GridView row. This is useful for passing row-specific information into an event handler as command arguments. To subscribe to a command event: <asp:GridView ID="GridView1" ... OnRowCommand="GridView1_RowCommand"> Buttons are t...

You can also apply a mixin globally. Use caution! Once you apply a mixin globally, it will affect every Vue instance created afterwards. When used properly, this can be used to inject processing logic for custom options: // inject a handler for `myOption` custom option Vue.mixin({ created: func...

When custom options are merged, they use the default strategy, which simply overwrites the existing value. If you want a custom option to be merged using custom logic, you need to attach a function to Vue.config.optionMergeStrategies: Vue.config.optionMergeStrategies.myOption = function (toVal, fro...

Mixins are a flexible way to distribute reusable functionalities for Vue components. A mixin object can contain any component options. When a component uses a mixin, all options in the mixin will be “mixed” into the component’s own options. // define a mixin object var myMixin = { created: fun...

RoboGuice is a framework that brings the simplicity and ease of Dependency Injection to Android, using Google's own Guice library. @ContentView(R.layout.main) class RoboWay extends RoboActivity { @InjectView(R.id.name) TextView name; @InjectView(R.id.thumbnail) Image...

Add the following pom to the dependencies section of your gradle build file : project.dependencies { compile 'org.roboguice:roboguice:3.+' provided 'org.roboguice:roboblender:3.+' }

The @ContentView annotation can be used to further alleviate development of activities and replace the setContentView statement : @ContentView(R.layout.myactivity_layout) public class MyActivity extends RoboActivity { @InjectView(R.id.text1) TextView textView; @Override protected ...

You can inject any type of resource, Strings, Animations, Drawables, etc. To inject your first resource into an activity, you'll need to: Inherit from RoboActivity Annotate your resources with @InjectResource Example @InjectResource(R.string.app_name) String name; @InjectResource(R.drawa...

You can inject any view using the @InjectView annotation: You'll need to: Inherit from RoboActivity Set your content view Annotate your views with @InjectView Example @InjectView(R.id.textView1) TextView textView1; @InjectView(R.id.textView2) TextView textView2; @InjectView(R.id.imag...

The UIAlertController available since iOS8 allows you to use the same alert object for either Action sheets or more classic alerts. The only difference is the UIAlertControllerStyle passed as a parameter when creating. This line changes from an AlertView to an ActionSheet, compared to some other ex...

It was common practice to use NSRunLoop to show modal UIAlertView to block code execution until user input is processed in iOS; until Apple released the iOS7, it broke few existing apps. Fortunately, there is a better way of implementing it with C#’s async/await. Here’s the new code taking advantag...

User input Imagine you want a user to enter a number via input. You want to ensure that the input is a number. You can use try/except for this: Python 3.x3.0 while True: try: nb = int(input('Enter a number: ')) break except ValueError: print('This is not a num...

To change the appearance of the keyboard, the following types can be set individually on every UITextFields property: keyboardType typedef NS_ENUM(NSInteger, UIKeyboardType) { UIKeyboardTypeDefault, // Default type for the current input method. UIKeyboardTypeASCIICapable, ...

Func provides a holder for parameterised anonymous functions. The leading types are the inputs and the last type is always the return value. // square a number. Func<double, double> square = (x) => { return x * x; }; // get the square root. // note how the signature matches the built ...

Functions have two built-in methods that allow the programmer to supply arguments and the this variable differently: call and apply. This is useful, because functions that operate on one object (the object that they are a property of) can be repurposed to operate on another, compatible object. Addi...