Tutorial by Examples: co

A bi-directional value converter utilizes two methods in your Value Converter class: toView and fromView these methods are aptly named to signify which direction the data is flowing. In our example we will be creating a prepend Value Converter which will make sure that an amount entered in our app ...

A Value Converter can be used alongside other value converters and you can infinitely chain them using the | pipe separator. ${myString | toUppercase | removeCharacters:'&,%,-,+' | limitTo:25} The above theoretical example firstly applies toUppercase which capitalizes our string. Then it app...

If the right-hand side of the assignment is a matrix, then in each iteration the variable is assigned subsequent columns of this matrix. some_matrix = [1, 2, 3; 4, 5, 6]; % 2 by 3 matrix for some_column = some_matrix display(some_column) end (The row vector version is a normal case of thi...

public function up() { $this->dropColumn('post', 'position'); $this->renameColumn('post', 'owner_id', 'user_id'); $this->alterColumn('post', 'updated', $this->timestamp()->notNull()->defaultValue('0000-00-00 00:00:00')); }

public function up() { $this->addColumn('post', 'position', $this->integer()); }

Set memory limit and disable swap limit docker run -it -m 300M --memory-swap -1 ubuntu:14.04 /bin/bash Set both memory and swap limit. In this case, container can use 300M memory and 700M swap. docker run -it -m 300M --memory-swap 1G ubuntu:14.04 /bin/bash

We can use Predefined Constants for Date format in date() instead of the conventional date format strings since PHP 5.1.0. Predefined Date Format Constants Available DATE_ATOM - Atom (2016-07-22T14:50:01+00:00) DATE_COOKIE - HTTP Cookies (Friday, 22-Jul-16 14:50:01 UTC) DATE_RSS - RSS (Fri, 22...

In PHP, an anonymous function has its own scope like any other PHP function. In JavaScript, an anonymous function can access a variable in outside scope. But in PHP, this is not permitted. $name = 'John'; // Anonymous function trying access outside scope $sayHello = function() { return &q...

Program units often make use of literal constants. These cover the obvious cases like print *, "Hello", 1, 1.0 Except in one case, each literal constant is a scalar which has type, type parameters and value given by the syntax. Integer literal constants are of the form 1 -1 -1_1 ...

Preconditions allows methods to provide minimum required values for input parameters Example... void DoWork(string input) { Contract.Requires(!string.IsNullOrEmpty(input)); //do work } Static Analysis Result...

Postconditions ensure that the returned results from a method will match the provided definition. This provides the caller with a definition of the expected result. Postconditions may allowed for simplied implmentations as some possible outcomes can be provided by the static analyizer. Example......

Sometimes it is appropriate to use an immutable empty collection. The Collections class provides methods to get such collections in an efficient way: List<String> anEmptyList = Collections.emptyList(); Map<Integer, Date> anEmptyMap = Collections.emptyMap(); Set<Number> anEmptySe...

Partial credit to this SO answer. List Concatenation aggregates a column or expression by combining the values into a single string for each group. A string to delimit each value (either blank or a comma when omitted) and the order of the values in the result can be specified. While it is not part ...

When running from the CLI, PHP exhibits some different behaviours than when run from a web server. These differences should be kept in mind, especially in the case where the same script might be run from both environments. No directory change When running a script from a web server, the current w...

Once registered a dependency can be retrieved by adding parameters on the Controller constructor. // ... using System; using Microsoft.Extensions.DependencyInjection; namespace Core.Controllers { public class HomeController : Controller { public HomeController(ITestServic...

It's possible to create a new ASP.NET Core project entirely from the command line using the dotnet command. dotnet new web dotnet restore dotnet run dotnet new web scaffolds a new "empty" web project. The web parameter tells the dotnet tool to use the ASP.NET Core Empty template. Use...

If a type wishes to have value semantics, and it needs to store objects that are dynamically allocated, then on copy operations, the type will need to allocate new copies of those objects. It must also do this for copy assignment. This kind of copying is called a "deep copy". It effective...

Setup monitoring beacons func initiateRegion(ref:BeaconHandler){ let uuid: NSUUID = NSUUID(UUIDString: "<UUID>") let beacon = CLBeaconRegion(proximityUUID: uuid, identifier: "") locationManager?.requestAlwaysAuthorization() //cllocation manager obj. ...

beacon = CLBeaconRegion(proximityUUID: <#NSUUID#>, major: <#CLBeaconMajorValue#>, identifier: <#String#>) // listening to all beacons with given UUID and major value beacon = CLBeaconRegion(proximityUUID: <##NSUUID#>, major: <##CLBeaconMajorValue#>, minor: <##C...

Open your command console and execute the following commands: $ sudo curl -LsS https://symfony.com/installer -o /usr/local/bin/symfony $ sudo chmod a+x /usr/local/bin/symfony