Tutorial by Examples: r

Send a Razor part to a @helper, for example a HTML div. @helper WrapInBox(Func<Object, HelperResult> content) { <div class="box">@content(null) </div> } //call @WrapInBox(@<div> I'm a inner div </div>)

@Helpers could be shared between views. They should be created in the folder App_Code @helper CreatePrimaryBootstrapButton(string label) { <button type="button" class="btn btn-primary">@label</button> } //call @MenuHelpers.CreatePrimaryBootstrapButton...

Sometimes it may be required to find out which directory consuming how much disk space especially when you are used df -h and realized your available disk space is low. du: du command summarizes disk usage of the set of FILEs, recursively for directories. It's often uses with -sh option: -s, --s...

First, ensure you have installed mongodb and express via npm. Then, in a file conventionally titled db.js, use the following code: var MongoClient = require('mongodb').MongoClient var state = { db: null, } exports.connect = function(url, done) { if (state.db) return done() M...

The following example is high level coverage of the key concepts and basic skeletal setup:- Collects credentials from the user (Usually from a login screen you've created) Authenticates the credentials with the server (stores custom authentication) Stores the credentials on the device Exte...

A frequent reason why your read operation may not work is because your security rules reject the operation, for example because you're not authenticated (by default a database can only be accessed by an authenticated user). You can see these security rule violations in the JavaScript console of you...

Add a -behaviour directive to your module to indicate that it follows a behaviour: -behaviour(gen_server). The American spelling is also accepted: -behavior(gen_server). Now the compiler will give a warning if you've forgotten to implement and export any of the functions required by the beha...

You can define your own behaviour by adding -callback directives in your module. For example, if modules implementing your behaviour need to have a foo function that takes an integer and returns an atom: -module(my_behaviour). -callback foo(integer()) -> atom(). If you use this behaviour in...

It's easiest to show a binary search on numbers using pseudo-code int array[1000] = { sorted list of numbers }; int N = 100; // number of entries in search space; int high, low, mid; // our temporaries int x; // value to search for low = 0; high = N -1; while(low < high) { mid = (...

In this iText 5 example, we'll create a text field and we'll add it to a PDF: public void manipulatePdf(String src, String dest) throws DocumentException, IOException { PdfReader reader = new PdfReader(src); PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest)); T...

In this iText 7 example, we'll create a text field and we'll add it to a PDF: public void manipulatePdf(String src, String dest) throws IOException { PdfReader reader = new PdfReader(src); PdfDocument pdf = new PdfDocument(reader, new PdfWriter(dest)); PdfAcroForm form = PdfAcroFor...

In this iText 5 example, we'll change the properties and the value of a text field: public void manipulatePdf(String src, String dest) throws DocumentException, IOException { PdfReader reader = new PdfReader(src); PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest)); ...

In this iText 7 example, we'll change the properties and the value of a text field: public void manipulatePdf(String src, String dest) throws IOException { PdfReader reader = new PdfReader(src); PdfDocument pdf = new PdfDocument(reader, new PdfWriter(dest)); PdfAcroForm form = PdfA...

To show you how work the views, we will assume that we want to query the document of type people. To do so, we will first need a design document that will hold our views. Note: for the purpose of the example, we will use many views inside of 1 design document. Therefore, in a production environment...

Integer Basics Standard ML of New Jersey v110.78 [built: Thu Jul 23 11:21:58 2015] - 6; val it = 6 : int - ~6; val it = ~6 : int - 6 + ~6; val it = 0 : int Integer Division - 6 div 3; val it = 2 : int - 6 div 4; val it = 0 : int - 3 div 6; val it = 0 : int Integer Value Bounds Us...

Real Number Basics - 6.0; val it = 6.0 : real - ~6.0; val it = ~6.0 : real - 6.0 + ~6.0; val it = 0.0 : real - 6.0 / 3.0; val it = 2.0 : real - 4.0 / 6.0; val it = 0.666666666667 : real Real Value Bounds Using Real Basis Library Functions - Real.maxFinite; val it = 1.79769313486E308 ...

Rounding Values midway between two integers go toward the nearest even value. - round(4.5); val it = 4 : int - round(3.5); val it = 4 : int Truncation val it = 4 : int - trunc(4.5); val it = 4 : int - trunc(3.5); val it = 3 : int Floor and Ceiling - ceil(4.5); val it = 5 : int - f...

Cannot add Integer and Real* - 5 + 1.0; stdIn:1.2-10.4 Error: operator and operand don't agree [overload conflict] operator domain: [+ ty] * [+ ty] operand: [+ ty] * real in expression: 5 + 1.0

- real(6); val it = 6.0 : real

Instead of running intensive tasks into JavaFX Thread that should be done into a Service.So what basically is a Service? A Service is a class which is creating a new Thread every time you are starting it and is passing a Task to it to do some work.The Service can return or not a value. Below is ...