Top 10 HTML5 features

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HTML5 contains many new interesting features that make the platform a capaple development platform. Sockets, SVG, geolocation, local storage and many more are included in the platform. In this one hour session, we will look at cool implementations of 10 features of HTML5

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Top 10 HTML5 features

  1. 1. Gill Cleeren @gillcleeren
  2. 2. Gill Cleeren MVP and Regional Director .NET Architect @ Ordina Trainer & speaker @gillcleeren gill@snowball.be
  3. 3. New elements Data input & validation SVGCanvas Audio & video Feature detection Geolocation Local storage Drag And Drop File API
  4. 4. • <canvas> • <audio> • <video> • <source> • <track> • <embed> • <datalist> • <keygen> • <output> • <bdi> • <wbr> • <article> • <aside> • <footer> • <details> • <summary> • <figure> • <figcaption> • <mark> • <time> • <meter> • <dialog> • <command> • <progress> • <ruby> • <rt> • <rp> • <header> • <hgroup> • <nav> • <section> • <main>
  5. 5. <article></article> article Blablabla…
  6. 6. <aside></aside> aside
  7. 7. <video> <source src="sample.mp4"> <source src="sample.ogv"> <source src="sample.webm"> Sorry, your browser is too old for this… </video> audio video
  8. 8. <canvas></canvas> canvas
  9. 9. <details> <summary> Sessions </summary> <p>HTML5 what’s new</p> </details> summary details
  10. 10. <embed src="sample.swf"> </embed> embed
  11. 11. <figure> <img src="mountain.png"> </figure> <figcaption> Screenshot of mountain </figcaption> figure figcaption
  12. 12. <header></header> <footer></footer> header footer
  13. 13. <main></main> main Blablabla…
  14. 14. <section></section> section
  15. 15. <mark></mark> mark
  16. 16. <meter min="0" max="100" value="30"> 30 percent </meter> meter
  17. 17. <progress value="30"> </progress> progress
  18. 18. <nav></nav> nav
  19. 19. <time datetime="2014-04- 17T22:23:24-8:00"> April 17th, 2014 </time> time
  20. 20. DEMO
  21. 21. • HTML5 adds support for common scenarios • Previously done often using JavaScript • Added: • Date pickers • Rendered by the browser • Sliders • Email • URL • …
  22. 22. • New input type • Supports date, month, week, time, datetime… • Support in most browsers isn’t optimal though <input type="date" name="birthDateTextBox" value="2014-1-16" />
  23. 23. • Type • Email • Error balloon will be shown when not valid • url • tel (adds no extra behaviour) • search (adds no extra behaviour) <input type="email" name="txtEmail" value="gill@snowball.be" /></br> <input type="url" name="txtUrl" value="http://www.techorama.be" /></br> <input type="tel" name="txtPhoneNumber" /></br> <input type="search" name="txtSearch" /></br>
  24. 24. • Type • number • range • color <input type="number" name="ageTextBox" /> <input type="range" name="ageTextBox" min="0" max="100" /> <input type="color" name="carColorTextBox" />
  25. 25. • Text fields now support placeholder attribute • autofocus sets the focus on a particular input • Using autocomplete, we set the browser to remembering previous values • And form can be used to separate an input type from the form
  26. 26. • novalidate can be used to specify that validation shouldn’t trigger on the form • Type range can be used to specify boundaries for the values <form id="myLoginForm" novalidate="novalidate"> <input type="text" name="usernameTextBox" required="required" /> <input type="password" name="passwordTextBox" required="required" /> <input type="submit" value="Sign In" /> </form> <input type="range" min="0" max="100" step="5" />
  27. 27. • New attributes • required • pattern • maxlength <input type="text" name="usernameTextBox" required="required" /> <input type="text" pattern="d{5}" name="zipCodeTextBox" /> <input type="text" name="firstNameTextBox" maxlength="10" />
  28. 28. DEMO
  29. 29. • Drawing surface • Inline element, flows with content • No visual by default • JavaScript API only • Content can be set to fallback content • Supports 2D drawings • Performance may not be consistent across browsers • Can use GPU • Supports CSS
  30. 30. • Games • Multimedia apps • Charts • Supported in most modern browsers!
  31. 31. • Create a <canvas> • Use document.getElementById() to find the canvas by id from JavaScript • Get hold of the 2d context • Create your drawings from JavaScript code <canvas id="myCanvas" width="300" height="150"></canvas> var canvas = document.getElementById("myCanvas"); var context = canvas.getContext("2d");
  32. 32. • Shapes • Rectangles • Paths • Lines • Arcs • Beziers • Rectangles • Clipping • All done a pixel-basis, not vector-based! • Support for transformations • Animations are not supported • Work using JavaScript though context.fillRect(x, y, width, height); context.strokeRect(x, y, width, height); context.clearRect(x, y, width, height);
  33. 33. context.beginPath(); context.moveTo(100, 75); context.lineTo(75, 100); context.lineTo(25, 100); context.fill();
  34. 34. • Adding text is similar to adding shapes • font can be used using CSS • In general, drawing text can fall back on CSS • Supports alignment • Horizontal and vertical • No multiline support context.fillText(text, x, y); context.strokeText(text, x, y);
  35. 35. • Image can be added onto the canvas • Can come from img, video or other canvas • Use the drawImage method var image = document.createElement("image"); image.onload = function () { context.drawImage(image, 10, 10); {; image.src = "logo.png";
  36. 36. DEMO
  37. 37. • SVG == Scalable Vector Graphics • XML model embedded in HTML • <svg> tag • Part of the regular DOM • Pretty old (2001), revisited in 2011 • Allows for vector-based, scalable graphics • Can sometimes replace the use of images and thus load faster <svg version="1.1" xmlns="http://www.w3.org/2000/svg"></svg>
  38. 38. • We can add shapes within the <svg> • Rectangles • Circles • Ellipse • Lines • Polylines • Polygons • Text <svg width="100" height="100"> <circle cx="50" cy="50" r="40" stroke="green" stroke-width="4" fill="blue" /> </svg>
  39. 39. <rect x="30" y="30" width="100" height="60" /> <circle cx="50" cy="30" r="20"/> <ellipse cx="400" cy="200" rx="350" ry="150" /> <polygon points="15 5, 100 8,6 150" />
  40. 40. <line x1="100" y1="300" x2="300" y2="100" stroke="b" /> <polyline points="50,375 150,375 150,325 250,325 250,375 350” /> <path class="SamplePath" d="M100,200 C100, 100 250, 100 250, 200 S400, 300 400, 200" />
  41. 41. • Using Filters, we can apply better graphical effects • Creating blurs and shadows • Less resources to download • Filter is a series of operations applied on an element • Uses defs element: contains definitions of elements such as filters • Defines a x, y, width and height where the filter is applied <svg version="1.1" xmlns="http://www.w3.org/2000/svg" > <defs> <filter id="f1" x="0" y="0" width="30" height="20"> </filter> </defs> </svg>
  42. 42. <svg height="110" width="110"> <defs> <filter id="f1" x="0" y="0"> <feGaussianBlur in="SourceGraphic" stdDeviation="15" /> </filter> </defs> <rect width="90" height="90" stroke="green" stroke-width="3" fill="yellow" filter="url(#f1)" /> </svg>
  43. 43. • SVG contains the ability to use linear and radial gradients • Also defined in defs element • Have an id defined • Defines a number of stops and offsets <svg height="150" width="400"> <defs> <linearGradient id="grad1" x1="0%" y1="0%" x2="100%" y2="0%"> <stop offset="0%" style="stop- color:rgb(255,255,0);stop-opacity:1" /> <stop offset="100%" style="stop-color:rgb(255,0,0);stop-opacity:1" /> </linearGradient> </defs> <ellipse cx="200" cy="70" rx="85" ry="55" fill="url(#grad1)" /> </svg>
  44. 44. DEMO
  45. 45. Media element Supported media types
  46. 46. • HTML5 defines the <audio> and <video> elements • Actual media is specified using the src attribute • Defines • autoplay • loop • preload: how should we buffer • volume • muted • controls • Work together with CSS • Video uses the aspect ratio from the content through • Poster frame can be used <video src="sample.m4v"></video> <audio src="sample.mp3"></audio> <video src="sample.m4v" poster="posterframe.png" width="100px" height="200px"></video>
  47. 47. • We get support for • Video: • WebM • H.264 • OggTheora • Audio • WebM • AAC • WAV • MP3 • OggVorbis • OggOpus • Which browser supports what depends on the weather though • Encoding in just one format is not a good idea!
  48. 48. • Using the source element, we can specify multiple sources • Browser stops at first element it supports • Recommended using the MIME type here <video width="320" height="240" controls> <source src="small.mp4" type="video/mp4"> <source src="small.ogv" type="video/ogg"> <source src="small.webm" type="video/webm"> Bad news...Your browser does not support the video tag. </video>
  49. 49. • You’ll have to write some JavaScript here! • play • pause • playbackRate • currentTime • duration • buffered var video = document.getElementById("thevideo"); video.play(); window.setTimeout(function () { video.pause(); }, 1000);
  50. 50. DEMO
  51. 51. • HTML5 develops fast • Browsers develop fast • Not all features work on all browsers • Sometimes they work but stop working in newer versions! • A solution is using • Browser detection • Feature detection • Polyfills
  52. 52. • Detecting which browser is being used • Based on this, we enable or disable functionalities • Main problem • Too many browsers • Too many versions of all these browsers • We have to make too many assumptions about which browser supports what feature • Still used for legacy browser/features though <!--[if IE 7]><div>rendered in Internet Explorer 7 only</div><![endif]-->
  53. 53. • Very often used today • Checks whether a certain feature is supported • If not, disable or use alternative if( window.addEventListener ) { // HTML that will be rendered if // addEventListener is available } else { // HTML that will be rendered if // addEventListener is not available } <video src="test.mp4"> <object src="test.mp4"> <a href="test.mp4"> Download the video </a> </object> </video>
  54. 54. • Free library that allows feature detection • Based on the return values from Modernizr, we can downgrade gracefully • Depending on the feature, Modernizr can provide behaviour to fill-in the missing behaviour • Not to the level of a polyfill though • Runs a number of tests • Creates elements in memory and checks if the returned values from the browser indicate if the feature is supported or not • Comes with MVC projects as well if (Modernizr.canvas) { // HTML that will be rendered if the // Canvas element is available }
  55. 55. • A shim or polyfill is a block of functionality to replace a missing browser feature • For missing addEventListener, you can use a polyfill that will add this behaviour • Modernizr adds some polyfill behaviour • Adds support for header, footer… elements in older browsers • Note that not everything can be fixed with polyfills!
  56. 56. DEMO
  57. 57. • Allows a web page to determine where we user physically is • Sometimes, by approach • Based on the device capabilities as well • Can be “one time” or continuous • Based on • GPS • WiFi • Cell phone (triangulation)
  58. 58. • JavaScript API • Defines • getCurrentPosition • watchPosition • clearWatch var watchid = navigator.geolocation.watchPosition (successCallback, errorCallback); function successCallback(e) { // success code } function errorCallback(e) { // failure code } navigator.geolocation.getCurrentPosition (successCallback, errorCallback); function successCallback(e) { // success code } function errorCallback(e) { // error code }
  59. 59. • Defines • PositionOptions • enableHighAccuracy • timeout • maximumAge • Position • Coordinates • Latitude • Longitude • Altitude • Accuracy • Speed • Heading • PositionError navigator.geolocation.getCurrentPosition (successCallback, errorCallback, { enableHighAccuracy: true, maximumAge: 2000, timeout: 1000 }); function successCallback(e) { // success code } function errorCallback(e) { // failure code }
  60. 60. • If denied, error callback will fire with the PERMISSION_DENIED error
  61. 61. DEMO
  62. 62. • Common thing to do on the desktop • Add items to cart • Drag emails to folder • Used to be possible only using JavaScript • With HTML5, a new API is included • Events • Markup attributes to make elements draggable or accept drops • DataTransfer object
  63. 63. • draggable • Can be added on every element • Can be • true • false • auto: default to what the browser allows • dropzone • Can be added on every element • Can be • copy • move • link • Not supported currently <div draggable="true">Drag me please</div> <div dropzone="copy"> Drop something on me please </div>
  64. 64. • A number of events are included • dragstart • drag • dragenter • dragleave • dragover • drop • dropend • Can be added on the draggable element var div = document.getElementById('draggableDiv'); div.addEventListener('dragstart', doDragStart, false); function doDragStart(e) { // do something cool like opacity stuff for dragging }
  65. 65. • All is captured in the dataTransfer object • Includes the data that is sent during the dragging • Can be set in the dragStart • Data is accessible in the drop event • Defines a getData and setData function • Format • data var div = document.getElementById('draggableDiv'); div.addEventListener('dragstart', doDragStart, false); function doDragStart(a) { a.dataTransfer.setData("text/plain", "Hello TechDays"); }
  66. 66. DEMO
  67. 67. • Cookies… • Web storage • IndexedDB • File system • Other libraries exist such as store.js…
  68. 68. • Web storage can be local or session-based • Comparable to cookies • Simple text files stored on the client • Limited to 4kB and maximum number of cookies • Sent to the server with every request • Can be created and manipulated from JavaScript var expiredate = new Date(); expiredate.setDate(expiredate.getDate() + 20); var cookieData= ”data” + "; expires="+ expiredate.toUTCString(); document.cookie= "cookieName=" +cookieData;
  69. 69. • Offers also persistent storage on the client • More storage than cookies • Easier to manipulate from code • 2 options: • sessionStorage • localStorage • Both are implemented as a dictionary • Data is stored as strings (objects need to be converted to strings using JSON.stringify) • Amount of available storage is dependent on the browser • Usually around 5MB
  70. 70. • localStorage • Keeps data even if session is removed • Closing browser has no effect on storage • Spans multiple windows and tabs • sessionStorage • Per page per window • Separate instances of the site use different storage
  71. 71. • length • clear() • getItem(key) • setItem(key, value) • removeItem(key) • key(index) • onStorage event fires when a value is changed var item = localStorage.getItem(“itemKey”); localStorage.setItem(“key”, “value”); window.addEventListener("storage", writelogs, false); function writelogs(e) { console.log(e.key); console.log(e.oldValue); console.log(e.newValue); console.log(e.url); console.log(e.storageArea); }
  72. 72. DEMO
  73. 73. • Most languages can work with files • JavaScript couldn’t however • Changed with HTML5 • Is an asynchronous API • API defines File and Blob objects • Also defines functions to read and write files
  74. 74. • File API defines a number of important objects • Blob: raw, immutable data • File: a typical file representation • FileList: list of one or more File objects • FileReader: used to read file contents • Each defines a number of properties and functions • Blob: slice(), size • File: name, lastModifiedDate var blobClone = blob.slice(); var blobClone2 = blob.slice(0, blob.size); var blobChunk = blob.slice(0, Math.round(blob.size/2));
  75. 75. • We can access files through file input or DataTransfer (Drag and drop) • Setting multiple on the file input allows selecting more than one file function readSelectedFiles(e) { var files = e.target.files; for (var i = 0; i < files.length; i++) { console.log(files.item(i).name); console.log(files.item(i).size); console.log(files.item(i).lastModifiedDate.toLocaleDateString()); } } document.getElementById('file').addEventListener('change', readSelectedFiles, false);
  76. 76. • Once we have the files, we can read them using the FileReader • Defines readAsText, readAsDataUrl, readAsArrayBuffer… and events such as onloadstart, onload, onerror… function readSelectedFiles(e) { var files = e.target.files; for (var i = 0; i < files.length; i++) { var reader = new FileReader(); reader.onload = (function(theFile) { return function(e) { console.log(e.target.result); }; })(files[i]); reader.readAsText(files[i]); } } document.getElementById('file').addEventListener('change', readSelectedFiles, false);
  77. 77. DEMO
  78. 78. • HTML5 adds a great number of features to the language • Many, previously impossible scenarios now become possible
  79. 79. Gill Cleeren @gillcleeren

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