When you want to test how an web-application reacts in a specific resolution, you can set up a specific Selenium driver for some tests:

 Before('@chrome320x480') do
     Capybara.current_driver = :chrome320x480
 end

 After('@chrome320x480') do
    Capybara.use_default_driver 
 end

You can use either chromium or chrome beta (as of 2012.05 the Version "19.0.1084.41 beta" works), or any other member of the family. It only needs to supports the "--window-size" command-line switch. [See this list](http://peter.sh...

In order to navigate through the browser history. you can manipulate the window.history object via javascript like follows:

When /^I go back in the browser history$/ do
  page.evaluate_script('window.history.back()')
end 

For further functions of the window and history objects check out this link.

An improved version of this step is now part of our gem spreewald on Github.

Spreewald gives you steps like these:

When I enter "text" into the browser dialog

Also see Accept or deny JavaScript confirmation dialogs in Capybara/Selenium.

You can use this code:

function scrollToLine($textarea, lineNumber) {
  var lineHeight = parseInt($textarea.css('line-height'));
  $textarea.scrollTop(lineNumber * lineHeight);      
}

Some caveats about this code:

1. Your textarea needs to have a line-height in Pixels.
2. The code will scroll to the line number in the text area, not the line number of the original text. These will differ if any lines wrap at the edge of the textarea.

Also see our solution for [scrolling a textarea to a given position with jQuery](htt...

Controller responses often include Javascript code that contains values from Ruby variables. E.g. you want to call a Javascript function foo(...) with the argument stored in the Ruby variable @foo. You can do this by using ERB tags (<%= ruby_expression %>) or, in Haml, interpolation syntax (#{ruby_expression}).

In any case you will take care of proper quoting and escaping of quotes, line feeds, etc. A convenient way to do this is to use Object#json, which is defined for Ruby strings, numb...

By default, Google Analytics tracks the current URL for every request. Sometimes you will want to track another URL instead, for example:

• When an application URL contains a secret (e.g. an access token)
• When you want to track multiple URLs under the same bucket
• When you want to track interactions that don't have a corresponding URL + request (e.g. a Javascript button or a PDF download)

Luckily the Analytics code snippet allows you to freely choose what path is being tracked. Simple change this:

ga('send', 'pageview');

......

zClip is a lightweight jQuery "copy to clipboard" plugin built using the popular Zero Clipboard library. This plugin uses an invisible Adobe Flash movie that is fully compatible with Flash Player 10 and below.

A small library to provide the Rails I18n translations in Javascript clients.

CodeMirror is a JavaScript component that provides a code editor in the browser. When a mode is available for the language you are coding in, it will color your code, and optionally help with indentation.

This is a demo of the "Tabby" Javascript jQuery plugin to use tabs in regular textareas to make them suitable for in-browser coding of languages like HTML, CSS, Javascript, or your favorite server-side language. The idea is to be able to use a press of the TAB button or SHIFT+TAB to indent or outdent your code.

KeyboardJS is a library for binding to keys or key combos

If you need to debug Analytics tracking, consider using this chrome extension. It will replace the tracking code with a debug version that prints debugging info to the JavaScript console.

Developers these days are spoiled with choice when it comes to selecting an MV* framework for structuring and organizing JavaScript web apps. Backbone, Spine, Ember (SproutCore 2.0), JavaScriptMVC... the list of new and stable solutions goes on and on, but just how do you decide on which to use in a sea of so many options?

To help solve this problem, we created TodoMVC - a project which offers the same Todo application implemented using MV* concepts in most of the popular JavaScript MV* frameworks of today.

Solutions look and feel the same...

A lightweight javascript date library for parsing, manipulating, and formatting dates.

This is a very general introduction to MV* Javascript frameworks. This card won't tell you anything new if you are already familiar with the products mentioned in the title.

As web applications move farther into the client, Javascript frameworks have sprung up that operate on a higher level of abstraction than DOM manipulation frameworks like jQuery and Prototype. Such high-level frameworks typically offer support for client-side view rendering, routing, data bindings, etc. This is useful, and when you write a moderately complex Javascript ...

turn.js is a plugin for jQuery that adds a beautiful transition similar to real pages in a book or magazine for HTML5.

I tested it successfully on Chrome, Firefox and IE9.

You can use text-overflow to truncate a text using CSS but it does not fit fancy requirements.

Here is a hack for the special case where you want to truncate one of two strings in one line that can both vary in length, while fully keeping one of them. See this example screenshot where we never want to show an ellipsis for the distance:

![Flexible overflow with optional ellipsis](https://makandracards.com/makandra/5885-a-flexible-overflow-ellipsis/at...

When using Rails to truncate strings, you may end up with strings that are still too long for their container or are not as long as they could be. You can get a prettier result using stylesheets.

The CSS property text-overflow: ellipsis has been around for quite a long time now but since Firefox did not support it for ages, you did not use it. Since Firefox 7 you can!

Note that this only works for single-line texts. If you want to truncate tests across multiple lines, use a JavaScript solution like...

Chrome now supports desktop notifications using WebKit's webkitNotifications API. This means you can create popup bubbles from Javascript.

Most of the JavaScript snippets have code that manipulates the DOM. For that reason dom manipulating javascript code should have been executed after the DOM has loaded completely. That means when the browser has finished HTML parsing and built the DOM tree. At that time, you can manipualte the DOM although not all resources (like images) are fully loaded.

The following snippets show how you can do this with plain JavaScript, jquery or prototype ([dom ready ...

Twitter's Bootstrap CSS blueprint as a jQuery UI theme. Even if you don't want to use Bootstrap as a CSS framework, this theme looks better than jQuery UI's default theme.

jQuery UI's date picker and date time picker doesn't work on touch interfaces.

Solution 1: Use Mobiscroll

Another way is to detect touch devices and for those devices use the Date and DateTime picker from Mobiscroll instead:

if (isTouchDevice()) {
  $('.date_picker').scroller();
} else...