Tutorial by Examples: f

Animations with keyframes

For multi-stage CSS animations, you can create CSS @keyframes. Keyframes allow you to define multiple animation points, called a keyframe, to define more complex animations. Basic Example In this example, we'll make a basic background animation that cycles between all colors. @keyframes rainbow...

CSS • Animations

New object from prototype

In JavaScript, any object can be the prototype of another. When an object is created as a prototype of another, it will inherit all of its parent's properties. var proto = { foo: "foo", bar: () => this.foo }; var obj = Object.create(proto); console.log(obj.foo); console.log(obj....

JavaScript • Inheritance

Handling the error when getting metadata for a non-existing path using the Dropbox .NET library

This example uses the Dropbox .NET library to try to get the metadata for an item at a particular path, and checks for a NotFound error: try { var metadata = await this.client.Files.GetMetadataAsync("/non-existant path"); Console.WriteLine(metadata.Name); } catch (Dropbox.Api.A...

Dropbox API • Getting file metadata

Containers / DI Frameworks

Whilst extracting dependencies out of your code so that they can be injected makes your code easier to test, it pushes the problem further up the hierarchy and can also result in objects that are difficult to construct. Various dependency injection frameworks / Inversion of Control Containers have ...

unit-testing • Dependency Injection

For loop

A for loop executes statements in the loop body, while the loop condition is true. Before the loop initialization statement is executed exactly once. After each cycle, the iteration execution part is executed. A for loop is defined as follows: for (/*initialization statement*/; /*condition*/; /*it...

C++ • Loops

Capture by reference

If you precede a local variable's name with an &, then the variable will be captured by reference. Conceptually, this means that the lambda's closure type will have a reference variable, initialized as a reference to the corresponding variable from outside of the lambda's scope. Any use of the v...

C++ • Lambdas

Default capture

By default, local variables that are not explicitly specified in the capture list, cannot be accessed from within the lambda body. However, it is possible to implicitly capture variables named by the lambda body: int a = 1; int b = 2; // Default capture by value [=]() { return a + b; }; // OK;...

C++ • Lambdas

Your First Controller

A controller is a basic structure used in Angular to preserve scope and handle certain actions within a page. Each controller is coupled with an HTML view. Below is a basic boilerplate for an Angular app: <!DOCTYPE html> <html lang="en" ng-app='MyFirstApp'> <head...

AngularJS • Controllers

Creating a backup of a database or table

Create a snapshot of a whole database: mysqldump [options] db_name > filename.sql Create a snapshot of multiple databases: mysqldump [options] --databases db_name1 db_name2 ... > filename.sql mysqldump [options] --all-databases > filename.sql Create a snapshot of one or more tables...

MySQL • Backup using mysqldump

Specifying username and password

> mysqldump -u username -p [other options] Enter password: If you need to specify the password on the command line (e.g. in a script), you can add it after the -p option without a space: > mysqldump -u username -ppassword [other options] If you password contains spaces or special chara...

MySQL • Backup using mysqldump

Restoring a backup of a database or table

mysql [options] db_name < filename.sql Note that: db_name needs to be an existing database; your authenticated user has sufficient privileges to execute all the commands inside your filename.sql; The file extension .sql is fully a matter of style. Any extension would work. You cannot spe...

MySQL • Backup using mysqldump

Conversion to function pointer

If a lambda's capture list is empty, then the lambda has an implicit conversion to a function pointer that takes the same arguments and returns the same return type: auto sorter = [](int lhs, int rhs) -> bool {return lhs < rhs;}; using func_ptr = bool(*)(int, int); func_ptr sorter_func = ...

C++ • Lambdas

Support for legacy browsers

In older browsers where Date.now() is unavailable, use (new Date()).getTime() instead: t = (new Date()).getTime(); Or, to provide a Date.now() function for use in older browsers, use this polyfill: if (!Date.now) { Date.now = function now() { return new Date().getTime(); }; }

JavaScript • Timestamps

Reading from a file synchronously

For any file operations, you will need the filesystem module: const fs = require('fs'); Reading a String fs.readFileSync behaves similarly to fs.readFile, but does not take a callback as it completes synchronously and therefore blocks the main thread. Most node.js developers prefer the asynch...

Node.js • Filesystem I/O

SMS Notifications with plivo

There are two ids you will need from your plivo account. Replace authid and authtoken in this snippet with those values. The src value should also be a valid number assigned to your account. dst can be any number you want, or multiple seperated by <. notification sms { post = https://authid:a...

Bosun • Notifications: Overview

Email Notifications

To send email notifications you need to add the following settings to your config file: #Using a company SMTP server (note only one can be define) smtpHost = mail.example.com:25 emailFrom = [email protected] #Using Gmail with TLS and username/password smtpHost = smtp.gmail.com:587 emailFrom ...

Bosun • Notifications: Overview

Slack Notifications

#Post to a slack.com chatroom via their Incoming Webhooks integration notification slack{ post = https://hooks.slack.com/services/abcdefg/abcdefg/abcdefghijklmnopqrstuvwxyz body = {"text": {{.|json}}} } #To customize the icon and user use: # body = {"text": {{.|js...

Bosun • Notifications: Chat Systems

HTTP GET/POST Notifications

Alert incidents can be sent to other system using HTTP GET or HTTP POST requests. You can either send the rendered alert directly (using markdown in the template perhaps) or use body = ... {{.|json}} ... and contentType to send the alert data over as part of a JSON object. Another approach is to onl...

Bosun • Notifications: Overview

Potential Pitfall: Extensions are Resolved Statically

The extension method to be called is determined at compile-time based on the reference-type of the variable being accessed. It doesn't matter what the variable's type is at runtime, the same extension method will always be called. open class Super class Sub : Super() fun Super.myExtension()...

Kotlin • Extension Methods

Using a mocking framework as a stub

The terms Mock and Stub can often become confused. Part of the reason for this is that many mocking frameworks also provide support for creating Stubs without the verification step associated with Mocking. Rather than writing a new class to implement a stub as in the "Using a stub to supply c...

unit-testing • Test Doubles