Tutorial by Examples: en

The cursor builds on top of and depends on the raycaster component. If we want to customize the raycasting pieces of the cursor, we can do by changing the raycaster component properties. Say we want set a max distance, check for intersections less frequently, and set which objects are clickable: &l...

To fix entities onto the camera such that they stay within view no matter where the user looks, you can attach those entities as a child of the camera. Use cases might be a heads-up display (HUD). <a-entity camera look-controls> <a-entity geometry="primitive: plane; height: 0.2; wi...

The recommended way is to write a component, and attach it to the scene element. The scene and its children will be initialized before this component. AFRAME.registerComponent('do-something', { init: function () { var sceneEl = this.el; } }); <a-scene do-something></a-scene...

_id is a 12 bytes hexadecimal number which assures the uniqueness of every document. You can provide _id while inserting the document. If you didn't provide then MongoDB provide a unique id for every document. These 12 bytes first 4 bytes for the current timestamp, next 3 bytes for machine id, next ...

Install properties reader: npm install properties-reader --save Create a directory env to store your properties files: mkdir env Create environments.js: process.argv.forEach(function (val, index, array) { var arg = val.split("="); if (arg.length > 0) { ...

In this example, we take a sine curve plot and add more features to it; namely the title, axis labels, title, axis ticks, grid and legend. # Plotting tutorials in Python # Enhancing a plot import numpy as np import matplotlib.pyplot as plt x = np.linspace(0, 2.0*np.pi, 101) y = np.sin(x) ...

The following are some of the common extensions used in Fortran source files and the functionalities they can work on. Lowercase f in the extension These files do not have the features of preprocessor directives similar to C-programming language. They can be directly compiled to create object file...

Because Node.js runs on a single process uncaught exceptions are an issue to be aware of when developing applications. Silently Handling Exceptions Most of the people let node.js server(s) silently swallow up the errors. Silently handling the exception process.on('uncaughtException', functio...

Many custom views need to accept user interaction in the form of touch events. You can get access to touch events by overriding onTouchEvent. There are a number of actions you can filter out. The main ones are ACTION_DOWN: This is triggered once when your finger first touches the view. ACTION_MO...

ImageMagick includes a number of command-line utilities for manipulating images. Here we will use compare command-line tool. compare tool is very useful. Suppose you want to test (e.g. layout, color, icons etc.) the difference between your expected design UI HTML file with actual result of JSP...

function openDatabase(dbName) { var request = indexedDB.open(dbName); request.onsuccess = function (e) { var database = request.result; if (database) { console.log("Database initialized."); } else { console.error("Database is not initialized!");...

There are two steps that the code from example 1 carried out: one was tokenizing the input, which means it looked for symbols that constitute the arithmetic expression, and the second step was parsing, which involves analysing the extracted tokens and evaluating the result. This section provides a ...

This section explains how the tokenized input from Part 1 is processed - it is done using Context Free Grammars (CFGs). The grammar must be specified, and the tokens are processed according to the grammar. Under the hood, the parser uses an LALR parser. # Yacc example import ply.yacc as yacc ...

This method extends the jQuery prototype ($.fn) object to provide new custom methods that can be chained to the jQuery() function. For example: <div>Hello</div> <div>World!</div> <script> jQuery.fn.extend({ // returns combination of div texts as a result g...

Use nic to create a new project Enter this command in your terminal $THEOS/bin/nic.pl NIC 2.0 - New Instance Creator ------------------------------ [1.] iphone/activator_event [2.] iphone/application_modern [3.] iphone/cydget [4.] iphone/flipswitch_switch [5.] iphone/framework ...

Background Model Listener hook's are a type of Liferay plugin that listens for events taken on an model and executes code in response. Model Listener hooks are similar to Custom Struts Action hooks in that they respond to an action taken in the portal. However while Struts actions respond to an a...

BottomSheet DialogFragment opens up in STATE_COLLAPSED by default. Which can be forced to open to STATE_EXPANDEDand take up the full device screen with help of the following code template. @NonNull @Override public Dialog onCreateDialog(Bundle savedInstanceState) { BottomSheetDialog dialog = ...

If you have: operator fun <R> String.invoke(block: () -> R) = { try { block.invoke() } catch (e: AssertException) { System.err.println("$this\n${e.message}") } } You can write the following DSL-like code: "it should return 2" { parse("1 + 1").bu...

In PHP, variable values have an associated "truthiness" so even non-boolean values will equate to true or false. This allows any variable to be used in a conditional block, e.g. if ($var == true) { /* explicit version */ } if ($var) { /* $var == true is implicit */ } Here are some fun...

For the most printing clients, is extremely useful to know if a print job has finished or failed. The Java Print Service API provide some functionalities to get informed about these scenarios. All we have to do is: provide an implementation for PrintJobListener interface and register this impl...