Tutorial by Examples: ch

Create a Security class to run your ACL logic. <?php namespace Plugins; use Phalcon\Events\Event; use Phalcon\Mvc\Dispatcher; use Phalcon\Acl; use Phalcon\Acl\Role; use Phalcon\Acl\Resource; use Phalcon\Acl\Adapter\Memory as AclList; class Security extends \Phalcon\Mvc\User\Plugin ...

Sometimes you need to match a literal (sub-)string with a regular expression despite that substring containing RE metacharacters. While yes, it's possible to write code to insert appropriate backslashes to make that work (using string map) it is easiest to just prefix the pattern with ***=, which ma...

null returns True if there are no elements a in a foldable structure t a, and False if there is one or more. Structures for which null is True have a length of 0. ghci> null [] True ghci> null [14, 29] False ghci> null Nothing True ghci> null (Right 'a') False ghci> null ('x'...

To check if a value exits in a WeakSet, use the .has() method. const obj1 = {}, obj2 = {}; const weakset = new WeakSet([obj1]); console.log(weakset.has(obj1)); // true console.log(weakset.has(obj2)); // false

Once an object has an effective type, you should not attempt to modify it through a pointer of another type, unless that other type is a character type, char, signed char or unsigned char. #include <inttypes.h> #include <stdio.h> int main(void) { uint32_t a = 57; // conversion...

Warning! Apply shadows sparingly! Applying shadowing is expensive and is multiplicatively expensive if you apply shadowing inside an animation loop. Instead, cache a shadowed version of your image (or other drawing): At the start of your app, create a shadowed version of your image in a secon...

Create a Job To add a job first we have to use a stored procedure named sp_add_job USE msdb ; GO EXEC dbo.sp_add_job @job_name = N'Weekly Job' ; -- the job name Then we have to add a job step using a stored procedure named sp_add_jobStep EXEC sp_add_jobstep @job_name = N'W...

As the characters/digits can be anywhere within the string, we require lookaheads. Lookaheads are of zero width meaning they do not consume any string. In simple words the position of checking resets to the original position after each condition of lookahead is met. Assumption :- Considering non-wo...

Pattern matching on tuples uses the tuple constructors. To match a pair for example, we'd use the (,) constructor: myFunction1 (a, b) = ... We use more commas to match tuples with more components: myFunction2 (a, b, c) = ... myFunction3 (a, b, c, d) = ... Tuple patterns can contain comple...

The :only-child CSS pseudo-class represents any element which is the only child of its parent. HTML: <div> <p>This paragraph is the only child of the div, it will have the color blue</p> </div> <div> <p>This paragraph is one of the two children of the ...

What: Caching can optimize computation in Spark. Caching stores data in memory and is a special case of persistence. Here is explained what happens when you cache an RDD in Spark. Why: Basically, caching saves an interim partial result - usually after transformations - of your original data. So, ...

This is an example of a simple GET API call wrapped in a promise to take advantage of its asynchronous functionality. var get = function(path) { return new Promise(function(resolve, reject) { let request = new XMLHttpRequest(); request.open('GET', path); request.onload = resolve; ...

Let's assume that we have one row in Company table with companyId 1. We can insert row in employee table that has companyId 1: insert into Employee values (17, 'John', 1) However, we cannot insert employee that has non-existing CompanyId: insert into Employee values (17, 'John', 111111) Msg ...

After installing a Java SDK, it is advisable to check that it is ready to use. You can do this by running these two commands, using your normal user account: $ java -version $ javac -version These commands print out the version information for the JRE and JDK (respectively) that are on your sh...

>>> import os >>> os.stat(path_to_file).st_size == 0 or >>> import os >>> os.path.getsize(path_to_file) > 0 However, both will throw an exception if the file does not exist. To avoid having to catch such an error, do this: import os def is_empty_...

A switch is a command line argument which takes no value. It can be specified with: desc.add_options() ("hidden", po::bool_switch()->default_value(false), "Hide your name"); And used with: if (vm["hidden"].as<bool>()) std::cout << "Hello ...

void SetupAsyncRead(SerialPort serialPort) { serialPort.DataReceived += (sender, e) => { byte[] buffer = new byte[4096]; switch (e.EventType) { case SerialData.Chars: var port = (SerialPort)sender; int bytesToRead = p...

using System.IO.Ports; namespace TextEchoService { class Program { static void Main(string[] args) { var serialPort = new SerialPort("COM1", 9600, Parity.Even, 8, StopBits.One); serialPort.Open(); string message = &quot...

using System; using System.Collections.Generic; using System.IO.Ports; using System.Text; using System.Threading; namespace AsyncReceiver { class Program { const byte STX = 0x02; const byte ETX = 0x03; const byte ACK = 0x06; const byte NAK = 0x15...

An integer type large enough to represent all characters of the largest supported extended character set, also known as the wide-character set. (It is not portable to make the assumption that wchar_t uses any particular encoding, such as UTF-16.) It is normally used when you need to store character...