Tutorial by Examples: io

To create \DateTimeImmutable in PHP 5.6+ use: \DateTimeImmutable::createFromMutable($concrete); Prior PHP 5.6 you can use: \DateTimeImmutable::createFromFormat(\DateTime::ISO8601, $mutable->format(\DateTime::ISO8601), $mutable->getTimezone());

Workflows can be somewhat limited in their functionality; for example, workflows cannot interact with line items. The Workflow Action script type is intended to be invoked by a Workflow to add scripting functionality to accomplish what the workflow itself cannot. Workflow Actions have a single onAc...

Lastly, we have the Bundle Installation script type, which provides several events that allow us to interact with the installation, update, and uninstallation of a particular bundle. This is a rarely-encountered script type, but important to be aware of nonetheless. The Bundle Installation includes...

Describes a dependency relationship between actors, the parent and child releationship. Parent is unique because it has created the child actor, so the parent is responsible for reacting when failures happens in his child. And parent decides which choice needs to be selected. When a parent receives...

There are two type of supervision strategies that we follow to supervise any actor: One-For-One Strategy One-For-All Strategy case object ResumeException extends Exception case object StopException extends Exception case object RestartException extends Exception override v...

PHP lacks a build-in function to encrypt and decrypt large files. openssl_encrypt can be used to encrypt strings, but loading a huge file into memory is a bad idea. So we have to write a userland function doing that. This example uses the symmetric AES-128-CBC algorithm to encrypt smaller chunks of...

Suppose you have two views ViewA and ViewB Instance of ViewB is created inside ViewA, so ViewA can send message to ViewB's instance, but for the reverse to happen we need to implement delegation (so that using delegate ViewB's instance could send message to ViewA) Follow these steps to implement t...

Move to the SQL Server Management Studio menu bar (ALT) Activate the menu for a tool component (ALT+ HYPHEN) Display the context menu (SHIFT+F) Display the New File dialog box to create a file (CTRL+N) Display the Open Project dialog box to open an existing project (CTRL+SHIFT+0) Display the ...

In spark-shell: sc.version Generally in a program: SparkContext.version Using spark-submit: spark-submit --version

In Vim, your configuration file is ~/.vimrc, with further configuration files in ~/.vim. In Neovim, configuration files are located in ~/.config/nvim. There is also no ~/.nvimrc file. Instead, use ~/.config/nvim/init.vim. You can import your Vim configuration directly into Neovim using this Unix c...

SELECT NOW(3) does the trick.

%f is the fractional precision format specifier for the DATE_FORMAT() function. SELECT DATE_FORMAT(NOW(3), '%Y-%m-%d %H:%i:%s.%f') displays a value like 2016-11-19 09:52:53.248000 with fractional microseconds. Because we used NOW(3), the final three digits in the fraction are 0.

authenticate_with_http_token do |token, options| @user = User.find_by(auth_token: token) end You can test this endpoint with curl by making a request like curl -IH "Authorization: Token token=my-token" http://localhost:3000

get_option function is used to retrieve a value from from options table based on option name. You can use the following code to get email address of a WordPress site administrator. <?php echo get_option('admin_email'); ?> get_option() has an optional 2nd argument, which allows you to set ...

Given an m times n matrix A with n larger than m. The singular value decomposition [U,S,V] = svd(A); computes the matrices U,S,V. The matrix U consists of the left singular eigenvectors which are the eigenvectors of A*A.' while V consists of the right singular eigenvalues which are the eigenvec...

Template Generic Syntax template<typename T> void f(ParamType param); f(expr); Case 1: ParamType is a Reference or Pointer, but not a Universal or Forward Reference. In this case type deduction works this way. The compiler ignores the reference part if it exists in expr. The compiler t...

C++11 Type deduction using the auto keyword works almost the same as Template Type Deduction. Below are a few examples: auto x = 27; // (x is neither a pointer nor a reference), x's type is int const auto cx = x; // (cx is neither a pointer nor a reference), cs's type is const int ...

variables this local arguments

Code coverage is a measure used to how often each source code statement and branch is executed. This measure is usually required when running a test suite to ensure that as much of the code as possible is tested by the test suite. It can also be used during profiling to determine code hot-spots and ...

Before using gcov, source code should be compiled with gcc using the two flags, -fprofile-arcs and -ftest-coverage. This tells the compiler to generate the information and extra object file code required by gcov. gcc -fprofile-arcs -ftest-coverage hello.c Linking should also use the -fprofile-a...