Building Better Experiences with Responsive JavaScript

Responsive design has thus far focused on using media queries to alter the way our site looks using CSS. The next step is to look at how we can progressively enhance our site based on the the features of the device. This is going beyond what CSS can offer and moving into the realms of responsive javascript. There are already new browser API’s are arriving to enables this, with the matchMedia API we can target specific functionality based on whether a media query matches.

Similarly we can add extra functionality and loads additional assets based upon features like geolocation and the camera. This is not building separate sites, its just changing the functionality of a single site based on the users device to optimise their experience.
The aim of this talk is to help you learn about what you can do with responsive javascript. You will learn about how you can target specific functionality to different types of devices which enable you to optimise your user experience.

Transcript

1. Building Better Experiences with Responsive JavaScript Jonathan Fielding @jonthanfielding
2. About me • Full stack developer • Been building responsively for
 over 3 years • Creator of SimpleStateManager
3. I asked some developers about what responsive design meant to them
4. targeting different devices
5. @media screen and (max-width: 767px){ media queries
6. responsive grids
7. fluid layouts
8. These all focus on one thing
9. How the site looks
10. There is more to building a great responsive site than simply how it looks
11. We also need to consider how the site functions
12. Why change functionality • Devices come in all shapes 
 and sizes • Input methods vary between 
 devices • Device functionality ranges
13. Examples
14. accordion on mobile open content on desktop
15. single col on mobile equal columns on desktop
16. simple scrollable content on mobile parallax on desktop
17. new page on mobile lightbox on desktop
18. stacked content on mobile swappable panels on desktop
19. What do these examples tell us
20. It’s ok to have different journeys for different devices on a responsive site
21. Desktop journey
22. Mobile journey
23. Two ways to change functionality • Based on viewport size • Based on the features the 
 device supports
24. x How to change functionality based on the viewport
25. Two key browser API’s • window.onresize • window.matchMedia
26. window.resize
27. Methodology • Add event to window.onresize • Use conditional statements to detect current width of browser • Add debounce to resize event to 
 prevent it firing excessively
28. The code //debounce missing to keep example short $(window).on('resize', function(){ if ($('body').width() < 768) { console.log('mobile'); } });
29. Could get messy • Lots of code simply placed in an on resize event could potentially be messy • Need to ensure there is a clear logical separation between different targeted viewport sizes
30. How to achieve the 
 logical separation if ($('body').width() < 768) { isMobile(); } ! if ($('body').width() >= 768) { isDesktop(); }
31. Browser Support IE Chrome Firefox Safari Android
32. window.matchMedia
33. Methodology • Prepare a MediaQueryList by using a media query with window.matchMedia • Add listener to MediaQueryList • When listener fires check if its a match or unmatch
34. The code var mql = window.matchMedia("(max-width:768px)"); mql.addListener(function(e){ if(e.matches){ console.log('enter mobile'); } });
35. Browser Support IE 10+ Chrome 9+ Firefox 6+ Safari 5.1+ Android 3.0+
36. Real World Usage 80.63% of users have a browser that supports matchMedia
37. Libraries
38. Two popular libraries
39. SimpleStateManager (aka SSM)
40. What is SSM? • Responsive State Manager for JS • Uses Resize Event • Uses concept of states • Expandable with plugins
41. Setting up SSM Two methods to setup SSM • Download from Github • bower install SimpleStateManager
42. The API • addState - Add Responsive states • removeState - Remove Responsive states • ready - tell SSM the states are added and you are ready
43. Methodology • Prepare a state in the onEnter • Clean up a state in the onLeave • Define a onResize event per state (optional)
44. Adding a state ssm.addState({ id: “mobile”, maxWidth: 767, onEnter: function(){ console.log(‘enter mobile’); } }).ready();
45. Removing a state ssm.removeState('mobile');
46. Demo
47. Extending SSM SSM Plugins allow you to: • Extend the available state options • Wrap jQuery Plugins to add responsive functionality
48. Plugin Methodology • Add a custom config option • Use it like any other config option in your states
49. Add a config option ssm.addConfigOption({name:"maxHeight", test: function(){ if(typeof this.state.maxHeight === "number" && this.state.maxHeight <= window.innerHeight){ return true; } else{ return false; } }});
50. Using the config option ssm.addState({ maxHeight: 480, onEnter: function(){ console.log(‘enter mobile’); } }).ready();
51. Summary • Create responsive states with predefined rules of when it should be active • Add onEnter, onLeave and onResize events to a state • Use config options to add new tests
53. What is enquire.js • Awesome Media Queries in JavaScript • Uses matchMedia API • Manages registering and unregistering
54. Setting up enquire.js Two methods to setup enquire.js • Download from Github • bower install enquire
55. The API • register - registers a media query attaching it to a handler • unregister - unregisters a media query
56. Methodology • Register a media query with a handler • Handler will fire when media query matches • Unregister unneeded handlers
57. Registering a query enquire.register("(max-width: 767px)", { match : function() { console.log("enter mobile"); }, });
58. Unregistering a query enquire.unregister("(max-width: 767px)");
59. Demo
60. Summary In summary Enquire.js allows you to • Create listeners for media queries • Attach match and unmatch methods to your listeners
61. SSM vs Enquire.js SimpleStateManager Enquire.js method onresize matchMedia browser support IE7+, FF, O, C, S IE10+, FF, O, C, S API events Enter, Leave, Resize Enter, Leave Plugin Library yes no
62. In Summary • Looked at two API’s we can use for responsive JavaScript • Looked at SimpleStateManager and enquire.js as an option to simplify writing responsive JavaScript
63. x How to change functionality based device features
64. x
65. Methodology • Detect the features that a browser supports • Progressively enhance your site based on the features it supports
66. Using Modernizr if(Modernizr.geolocation){ console.log('Supports GeoLocation'); }
67. Use in conjunction with SSM • Create a SSM config option using Modernizr for the test
68. Add a config option ssm.addConfigOption({name:"touch", test: function(){ if(typeof this.state.touch === "boolean" && this.state.touch === Modernizr.touch){ return true; } else{ return false; } }});
69. Using the config option ssm.addState({ touch: true, maxWidth: 767, onEnter: function(){ console.log(‘is mobile device that supports touch events’); } }).ready();
70. So how do we build better experiences using Responsive JavaScript?
71. By targeting functionality based on the characteristics of a device
72. Optimising the journey our user follows to best suit the device
73. Demo code from this talk at ! https://github.com/jonathan-fielding/ ResponsiveJavaScriptTalkExamples
74. • Learn how to make your sites responsive • Chapter on Responsive JavaScript • http://bitly.com/NXusZn • 35% off eBook discount code: B3GW3B • 4 eBooks to give away today
75. Any Questions
76. Further Resources MDN - Testing Media Queries - mzl.la/18r5yGi MDN – MediaQueryList - mzl.la/1bxbbZJ MDN – Window.matchMedia - mzl.la/19qc3Yk SimpleStateManager – simplestatemanager.com Enquire.js - wicky.nillia.ms/enquire.js/ MatchMedia Polyfill - github.com/paulirish/matchMedia.js/ Jonathan Fielding’s Blog - jonathanfielding.com ! Demo code from this talk at ! https://github.com/jonathan-fielding/ ResponsiveJavaScriptTalkExamples