MQBE. Media Query Breakpoint Events

This small function creates JQuery events that are fired when you enter or leave a CSS media query state, for instance from desktop to tablet... etc. It's useful when you need to start or stop some JS functionallity depending on MediaQuery changes / states.

Installation

1a. Use as Rails gem

Simply include in your gemfile:

gem 'mqbe'

and run bundle install

Then add in your application.js (its recommend to be included just after JQuery)

//= require mqbe

1b. Use standalone

If you want to add it to your project by hand, copy dist/mqbe.js or dist/mqbe.min.js (minified) in your project and be sure that its included in the pages after JQuery.

2. Include CSS

The functionallity of MQBE depends on a little piece of CSS, where you can define your media query breakpoints. You must add an string to identify that state from the JS. It's easier that it sounds. Take a look to the code below.

Use only [a-zA-Z_] chars to define the string, and don't use hyphens -

/* DESKTOP */
body:after {
  content: 'desktop'; /* <- string that defines this state */
  display: none;
}

/* SMALL DESKTOP */
@media only screen and (max-width: 1200px) {
  body:after {
    content: 'small_desktop'; /* <- string that defines this state */
  }
}

/* TABLET */
@media only screen and (max-width: 1024px) {
  body:after {
    content: 'tablet'; /* <- string that defines this state */
  }
}

@media only screen and (max-width: 767px) {
  body:after {
    content: 'mobile'; /* <- string that defines this state */
  }
}

For the lazy ones, you can just include dist/mqbe.min.css which defines this 4 media queries and customize the breakpoints values to your project's needs.

3. Usage: Add events

Define you events related to your CSS breakpoint names on domready. You have two events available for each Media Query state: enter, and leave. enter its also fired when the page loads the first time.

Below you have an example.

$(document)
  .on('enter.mobile.mqbe', function() {
    // Especial flexsliders
    $('.flexslider-mobile-only').flexslider({
      animation: "slide",
      controlNav: false
    });
    // Filter groups
    $('.list-filters > .title').on('click', function() {
      $(this).parent().toggleClass('expanded');
    });
  })

  .on('leave.mobile.mqbe', function() {
    flexdestroy('.flexslider-mobile-only');
  });

All events are in the namespace mqbe so you can add a generic listener than will be triggered on every breakpoint.

$(document).on('mqbe', function() {
  // Do whatever you need on every defined breakpoints
});

You can clean the events from any state using the jquery off method.

$(document).off('enter.desktop.mqbe');

Also you can disable all mqbe events

$(document).off('mqbe');

Take a look to the example

You have an example in the demo directory, I recommend you to take a look to it to fully understand the idea.

Demo included in this repo.

Demo / Dist

MQBE uses gulp to serve a demo/test server and build dist versions.

Prerequisites

First you need to have node and gulp-cli installed on your environment.

Then install all dependencies, in repo's root:

$ npm install

Demo

To test and develop you can start a connect server watching src/*.js and src/*.scss at http://localhost:3000/.

$ gulp server
## or just
$ gulp

To build minified versions of MQBE in dist/ you must run.

$ gulp dist

Fixes / Changelog

• V.2.0.3 First Rails Gem release.

• V.2.0.2 Changing ot max-width and breakpoints in px.

• V.2.0.1 Changing max-width to max-device-width in mediaqueries due to browser zoom issues.

• V.2.0.0 Delegate events on jquery instead custom queues. Namespace .mqbe. Add generic event .mqbe on every breakpoint.

• V.1.0.5 Added gulp to generate minified and demo files.

• V.1.04 Renamed to MQBE.v.js. Added debounced resize. Now library initializes itself.

• V.1.03 Added event queue, and nex syntax. Added off method, and method chainning.

• V.1.01 Chrome 43 returns state with single quotes "'desktop'", added regex to clean that extra quotes