Tutorial by Examples: le

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...

To get random data from certain collection refer to $sample aggregation. db.emplyees.aggregate({ $sample: { size:1 } }) where size stands for number of items to select.

Let say you want to build your API to comply jsonapi.org specification and the result should look like: { "article": { "id": "305", "type": "articles", "attributes": { "title": "Asking Alexandria&q...

Introduces a while loop. int i = 0; // print 10 asterisks while (i < 10) { putchar('*'); i++; }

public enum Cassandra { DB; private Session session; private Cluster cluster; private static final Logger LOGGER = LoggerFactory.getLogger(Cassandra.class); /** * Connect to the cassandra database based on the connection configuration provided. * Multiple c...

Nested serializers by default don't support create and update. To support this without duplicating DRF create/update logic, it is important to remove the nested data from validated_data before delegating to super: # an ordinary serializer class UserProfileSerializer(serializers.ModelSerializer): ...

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...

To get a list of possible time_zone values in your MySQL server instance, use this command. SELECT mysql.time_zone_name.name Ordinarily, this shows the ZoneInfo list of time zones maintained by Paul Eggert at the Internet Assigned Numbers Authority. Worldwide there are appproximately 600 time z...

CREATE TABLE times ( dt DATETIME(3), ts TIMESTAMP(3) ); makes a table with millisecond-precision date / time fields. INSERT INTO times VALUES (NOW(3), NOW(3)); inserts a row containing NOW() values with millisecond precision into the table. INSERT INTO times VALUES ('2015-01...

ActionScript 2.0: _root.createTextField("message", 0, 5, 5, 300, 50); var tf:TextFormat = new TextFormat(); tf.color = 0xFF0000; tf.size = 32; tf.bold = true; message.setTextFormat(tf); message.text = "Hello World!"; First function creates a TextField named "mess...

For a non-main packages as well as main, instead of adding flags inside the code, write benchmarks in the test package , for example: func BenchmarkHello(b *testing.B) { for i := 0; i < b.N; i++ { fmt.Sprintf("hello") } } Then run the test with the profile flag ...

once a prof file has been generated, one can access the prof file using go tools: go tool pprof cpu.prof This will enter into a command line interface for exploring the profile Common commands include: (pprof) top lists top processes in memory (pprof) peek Lists all processes, use reg...

ember generate route foo --pod installing create app/pods/foo/route.js create app/pods/foo/template.hbs installing create tests/unit/pods/foo/route-test.js

var gulp = require('gulp'); // include plug-ins var uglify = require('gulp-uglify'), concat = require('gulp-concat'); // Minified file gulp.task('packjsMin', function() { return gulp.src('node_modules/angular/*.js') .pipe(concat('script.js')) .pipe(uglify()) .p...

You can use docker, without using docker daemon (engine), by using cloud providers. In this example, you should have a gcloud (Google Cloud util), that connected to your account docker-machine create --driver google --google-project `your-project-name` google-machine-type f1-large fm02 This exa...

DROP TABLE Database.table_name

There are two kinds of persistent storage modes in Redis: AOF and RDB. To temporarily disable RDB execute the following commands on the Redis command line: config set save "" to temporarily disable AOF execute the following from the Redis command line: config set appendonly no The...

A basic script showing the fundamentals of how to create/open, write to, and save an Excel spreadsheet. Using the AutoIt Excel library functions. ; Include definitions of the User Excel functions #include <Excel.au3> ; Include Message Box codes for the error messages #include <MsgBox...

Jquery selectors are used to manipulate DOM (Document object model), attach events, add element, remove element on runtime. SelectorDescriptionelement selectorelement selector are used to select particular element Ex: <p>Stackoverflow to help in understanding errors </p> To access this ...