Tutorial by Examples: n

Plugins - Getting Started

The jQuery API may be extended by adding to its prototype. For example, the existing API already has many functions available such as .hide(), .fadeIn(), .hasClass(), etc. The jQuery prototype is exposed through $.fn, the source code contains the line jQuery.fn = jQuery.prototype Adding functio...

jQuery • Plugins

Calculate Content Bounds (for i.e. dynamic cell heights)

A common use case for wanting to calculate the frame a label will take up is for sizing table view cells appropriately. The recommended way of doing this is using the NSString method boundingRectWithSize:options:attributes:context:. options takes String drawing options: NSStringDrawingUsesLineFr...

iOS • UILabel

Initial Usage Example

jquery-ui-rotatable is a plugin for jQuery UI that works in a similar way to Draggable and Resizable, without being as full-featured. By default, it puts a small rotation icon in the bottom left of whatever element you want to make rotatable. <html> <head> <title>My Ro...

jQuery UI Library • jQuery UI Rotatable Plug-in

Complex Example - jQuery UI Dynamicly Create Dialog

Generally, dialog relies on a div within the HTML. Sometimes you may want to create a dialog from scratch, programmatically. Here is an example of a complex modal dialog created dynamically with interactive functions. HTML <div id="users-contain" class="ui-widget"> &lt...

jQuery UI Library • Dialog

Use requestAnimationFrame to fade in element

View jsFiddle: https://jsfiddle.net/HimmatChahal/jb5trg67/ Copy + Pasteable code below: <html> <body> <h1>This will fade in at 60 frames per second (or as close to possible as your hardware allows)</h1> <script> // Fad...

JavaScript • requestAnimationFrame

Object.assign

The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object. Use it to assign values to an existing object: var user = { firstName: "John" }; Object.assign(user, {last...

JavaScript • Objects

Enum definition

An enum is a set of logically related constants. Enum Size Small Medium Large End Enum Public Sub Order(shirtSize As Size) Select Case shirtSize Case Size.Small ' ... Case Size.Medium ' ... Case Size.Large ' ....

Visual Basic .NET Language • Enum

Member initialization

Each of the enum members may be initialized with a value. If a value is not specified for a member, by default it's initialized to 0 (if it's the first member in the member list) or to a value greater by 1 than the value of the preceding member. Module Module1 Enum Size Small ...

Visual Basic .NET Language • Enum

Builder Pattern / C# / Fluent Interrface

public class Email { public string To { get; set; } public string From { get; set; } public string Subject { get; set; } public string Body { get; set; } } public class EmailBuilder { private readonly Email _email; public EmailBuilder() { _email = ...

Design patterns • Builder Pattern

Committing at a specific date

git commit -m 'Fix UI bug' --date 2016-07-01 The --date parameter sets the author date. This date will appear in the standard output of git log, for example. To force the commit date too: GIT_COMMITTER_DATE=2016-07-01 git commit -m 'Fix UI bug' --date 2016-07-01 The date parameter accepts t...

Git • Committing

Devise Controller Filters & Helpers

To set up a controller with user authentication using devise, add this before_action: (assuming your devise model is 'User'): before_action :authenticate_user! To verify if a user is signed in, use the following helper: user_signed_in? For the current signed-in user, use this helper: current_us...

Ruby on Rails • User Authentication in Rails

Destructuring an array

6 An array can be destructured when being assigned to a new variable. const triangle = [3, 4, 5]; const [length, height, hypotenuse] = triangle; length === 3; // → true height === 4; // → true hypotneuse === 5; // → true Elements can be skipped const [,b,,c] = [1, 2, 3, 4]; co...

JavaScript • Arrays

Reduce an array to chained promises

This design pattern is useful for generating a sequence of asynchronous actions from a list of elements. There are two variants : the "then" reduction, which builds a chain that continues as long as the chain experiences success. the "catch" reduction, which builds a chain t...

JavaScript • Promises

Covariance on an invariant trait

There is also a way to have a single method accept a covariant argument, instead of having the whole trait covariant. This may be necessary because you would like to use T in a contravariant position, but still have it covariant. trait LocalVariance[T]{ /// ??? throws a NotImplementedError de...

Scala Language • Type Variance

Reading or writing through a null pointer

int *ptr = nullptr; *ptr = 1; // Undefined behavior This is undefined behavior, because a null pointer does not point to any valid object, so there is no object at *ptr to write to. Although this most often causes a segmentation fault, it is undefined and anything can happen.

C++ • Undefined Behavior

No return statement for a function with a non-void return type

Omitting the return statement in a function which is has a return type that is not void is undefined behavior. int function() { // Missing return statement } int main() { function(); //Undefined Behavior } Most modern day compilers emit a warning at compile time for this kind o...

C++ • Undefined Behavior

Modifying a string literal

C++11 char *str = "hello world"; str[0] = 'H'; "hello world" is a string literal, so modifying it gives undefined behaviour. The initialisation of str in the above example was formally deprecated (scheduled for removal from a future version of the standard) in C++03. A num...

C++ • Undefined Behavior

Listening to Changes of contenteditable

Events that work with most form elements (e.g., change, keydown, keyup, keypress) do not work with contenteditable. Instead, you can listen to changes of contenteditable contents with the input event. Assuming contenteditableHtmlElement is a JS DOM object that is contenteditable: contenteditableH...

JavaScript • execCommand and contenteditable

Switch off properties during macro execution

It is best practice in any programming language to avoid premature optimization. However, if testing reveals that your code is running too slowly, you may gain some speed by switching off some of the application’s properties while it runs. Add this code to a standard module: Public Sub SpeedUp( _ ...

excel-vba • VBA Best Practices

Pattern matching on a map

%{username: username} = %{username: "John Doe", id: 1} # username == "John Doe" %{username: username, id: 2} = %{username: "John Doe", id: 1} ** (MatchError) no match of right hand side value: %{id: 1, username: "John Doe"}

Elixir Language • Pattern matching