Fundamental JavaScript [In Control 2009]

1. FUNDAMENTAL JAVASCRIPT Aaron Gustafson

2. DOM SCRIPTING (a.k.a. Document Manipulation via JavaScript)

3. FUNDAMENTAL JAVASCRIPT DHTML ๏ …was all about animation and interactivity ๏ ...was invented by marketing wonks ๏ ...is really three technologies: JavaScript, CSS & HTML ๏ ...carried a lot of baggage: browser-speciﬁc, forked code, screen only & non-standard markup ๏ ...was a maintenance nightmare IN CONTROL 2009 3

4. FUNDAMENTAL JAVASCRIPT DOM Scripting ๏ …is the web standards approach to manipulating documents ๏ ...only requires a scripting language and valid markup ๏ ...is browser independent ๏ ...makes use of progressive enhancement ๏ ...just makes sense IN CONTROL 2009 4

5. FUNDAMENTAL JAVASCRIPT The document <!DOCTYPE html PUBLIC quot;-//W3C//DTD XHTML 1.0 Strict//ENquot; quot;http://www.w3.org/TR/XHTML1/DTD/XHTML1-strict.dtdquot;> <html xmlns=quot;http://www.w3.org/1999/XHTMLquot; xml:lang=quot;enquot; lang=quot;enquot;> <head> <title>Page Title</title> <meta http-equiv=quot;content-typequot; content=quot;text/html; charset=utf-8quot; /> <meta http-equiv=quot;Content-Languagequot; content=quot;en-usquot; /> </head> <body> <h1>This is a heading</h1> <p>This is a paragraph with a <a href=quot;http://easy-reader.netquot;>link</a></p> <ul> <li>a list item</li> <li>another list item</li> <li>a third list item</li> </ul> </body> </html> IN CONTROL 2009 5

6. FUNDAMENTAL JAVASCRIPT The DOM html IN CONTROL 2009 6

7. FUNDAMENTAL JAVASCRIPT The DOM html head body title meta meta h1 p ul a li li li IN CONTROL 2009 6

8. FUNDAMENTAL JAVASCRIPT The DOM p this is a paragraph a . of text with a href=quot;http://easy-reader.netquot; link IN CONTROL 2009 6

9. FUNDAMENTAL JAVASCRIPT CSS getter { setter } IN CONTROL 2009 7

10. FUNDAMENTAL JAVASCRIPT CSS p { color: red; } IN CONTROL 2009 7

11. FUNDAMENTAL JAVASCRIPT CSS #footer { font-size: small; } IN CONTROL 2009 7

12. FUNDAMENTAL JAVASCRIPT DOM Scripting IN CONTROL 2009 8

13. FUNDAMENTAL JAVASCRIPT DOM Scripting var myNode = document.getter(); IN CONTROL 2009 8

14. FUNDAMENTAL JAVASCRIPT DOM Scripting myNode.setter(); IN CONTROL 2009 8

15. FUNDAMENTAL JAVASCRIPT Getters ๏ document.getElementById( ID ); ๏ document.getElementsByTagName( tagName ); ๏ element.getAttribute( attributeName ); IN CONTROL 2009 9

16. FUNDAMENTAL JAVASCRIPT Using getters ๏ var content = document.getElementById( 'content' ); ๏ var abbrs = document.getElementsByTagName( 'abbr' ); ๏ var title = abbrs[0].getAttribute( 'title' ); IN CONTROL 2009 10

17. FUNDAMENTAL JAVASCRIPT Language comparison ๏ English Get the element with the ID “content”. ๏ CSS #content { } ๏ DOM document.getElementById( 'content' ) IN CONTROL 2009 11

18. FUNDAMENTAL JAVASCRIPT Language comparison ๏ English Get all the paragraphs in a document. ๏ CSS p { } ๏ DOM document.getElementsByTagName( 'p' ); IN CONTROL 2009 12

19. FUNDAMENTAL JAVASCRIPT Language comparison ๏ English Get all the paragraphs within the element with the ID “content”. ๏ CSS #content p { } ๏ DOM document.getElementById( 'content' ) .getElementsByTagName( 'p' ); IN CONTROL 2009 13

20. FUNDAMENTAL JAVASCRIPT Content generation ๏ Bad: ‣ document.write(); ‣ innerHTML IN CONTROL 2009 14

21. FUNDAMENTAL JAVASCRIPT Content generation ๏ Good: ‣ document.createElement( tagName ); ‣ document.createTextNode( text ); ‣ element.setAttribute( name, value ); IN CONTROL 2009 15

22. FUNDAMENTAL JAVASCRIPT Generation in action ๏ var abbr = document.createElement( 'abbr' ); ๏ var text = document.createTextNode( 'TN' ); ๏ abbr.setAttribute( 'title', 'Tennessee' ); IN CONTROL 2009 16

23. FUNDAMENTAL JAVASCRIPT Adding to the DOM ๏ element.appendChild( newNode ); ๏ element.insertBefore( newNode, targetNode ); IN CONTROL 2009 17

24. FUNDAMENTAL JAVASCRIPT Adding to the DOM var abbr = document.createElement( 'abbr' ); var text = document.createTextNode( 'TN' ); abbr.setAttribute( 'title', 'Tennessee' ); abbr.appendChild( text ); var p = document.getElementsByTagName( 'p' )[0]; p.appendChild( abbr ); IN CONTROL 2009 18

25. TIME FOR AN EXAMPLE

26. FUNDAMENTAL JAVASCRIPT The idea Make use of the cite attribute in blockquotes. IN CONTROL 2009 20

27. FUNDAMENTAL JAVASCRIPT The document <!DOCTYPE html PUBLIC quot;-//W3C//DTD XHTML 1.0 Strict//ENquot; quot;http://www.w3.org/TR/XHTML1/DTD/XHTML1-strict.dtdquot;> <html xmlns=quot;http://www.w3.org/1999/XHTMLquot; xml:lang=quot;enquot; lang=quot;enquot;> <head> <title>Example 1</title> <meta http-equiv=quot;content-typequot; content=quot;text/html; charset=utf-8quot; /> <meta http-equiv=quot;Content-Languagequot; content=quot;en-usquot; /> </head> <body> <blockquote cite=quot;http://en.wikipedia.org/wiki/Progressive_Enhancementquot;> <p>Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference.</p> </blockquote> </body> </html> IN CONTROL 2009 21

28. FUNDAMENTAL JAVASCRIPT The page Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference. IN CONTROL 2009 22

29. FUNDAMENTAL JAVASCRIPT The document <!DOCTYPE html PUBLIC quot;-//W3C//DTD XHTML 1.0 Strict//ENquot; quot;http://www.w3.org/TR/XHTML1/DTD/XHTML1-strict.dtdquot;> <html xmlns=quot;http://www.w3.org/1999/XHTMLquot; xml:lang=quot;enquot; lang=quot;enquot;> <head> <title>Example 1</title> <meta http-equiv=quot;content-typequot; content=quot;text/html; charset=utf-8quot; /> <meta http-equiv=quot;Content-Languagequot; content=quot;en-usquot; /> </head> <body> <blockquote cite=quot;http://en.wikipedia.org/wiki/Progressive_Enhancementquot;> <p>Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference.</p> </blockquote> </body> </html> IN CONTROL 2009 23

30. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document 2. Get the value of the cite attribute 3. Create a new anchor element node 4. Set the href attribute of the anchor 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 24

31. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document 2. Get the value of the cite attribute 3. Create a new anchor element node 4. Set the href attribute of the anchor 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

32. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute 3. Create a new anchor element node 4. Set the href attribute of the anchor 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

33. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node 4. Set the href attribute of the anchor 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

34. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node createElement 4. Set the href attribute of the anchor 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

35. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node createElement 4. Set the href attribute of the anchor setAttribute 5. Create a new text node with the word “source” 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

36. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node createElement 4. Set the href attribute of the anchor setAttribute 5. Create a new text node with the word “source” createTextNode 6. Insert the text into the anchor 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

37. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node createElement 4. Set the href attribute of the anchor setAttribute 5. Create a new text node with the word “source” createTextNode 6. Insert the text into the anchor appendChild 7. Insert the anchor into the blockquote. IN CONTROL 2009 25

38. FUNDAMENTAL JAVASCRIPT The idea 1. Find all the blockquotes in a document getElementsByTagName 2. Get the value of the cite attribute getAttribute 3. Create a new anchor element node createElement 4. Set the href attribute of the anchor setAttribute 5. Create a new text node with the word “source” createTextNode 6. Insert the text into the anchor appendChild 7. Insert the anchor into the blockquote. appendChild IN CONTROL 2009 25

39. FUNDAMENTAL JAVASCRIPT The code var quotes = document.getElementsByTagName( 'blockquote' ); for( var i=0; i < quotes.length; i++ ){ var source = quotes[i].getAttribute( 'cite' ); if( source ){ var link = document.createElement( 'a' ); link.setAttribute( 'href', source ); var text = document.createTextNode( 'source' ); link.appendChild( text ); quotes[i].appendChild( link ); } } IN CONTROL 2009 26

40. FUNDAMENTAL JAVASCRIPT The code var quotes = document.getElementsByTagName( 'blockquote' ); for( var i=0; i < quotes.length; i++ ){ var source = quotes[i].getAttribute( 'cite' ); if( source ){ var link = document.createElement( 'a' ); link.setAttribute( 'href', source ); var text = document.createTextNode( 'source' ); link.appendChild( text ); var para = document.createElement( 'p' ); para.className = 'attribution'; para.appendChild( link ); quotes[i].appendChild( para ); } } IN CONTROL 2009 27

41. FUNDAMENTAL JAVASCRIPT The code function sourceQuotes(){ var quotes = document.getElementsByTagName( 'blockquote' ); for( var i=0; i < quotes.length; i++ ){ var source = quotes[i].getAttribute( 'cite' ); if( source ){ var link = document.createElement( 'a' ); link.setAttribute( 'href', source ); var text = document.createTextNode( 'source' ); link.appendChild( text ); var para = document.createElement( 'p' ); para.className = 'attribution'; para.appendChild( link ); quotes[i].appendChild( para ); } } } window.onload = sourceQuotes; IN CONTROL 2009 28

42. FUNDAMENTAL JAVASCRIPT The result Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference. IN CONTROL 2009 29

43. FUNDAMENTAL JAVASCRIPT The result Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference. source IN CONTROL 2009 30

44. PROGRESSIVE ENHANCEMENT

45. WHAT IS PROGRESSIVE ENHANCEMENT?

46. PROGRESSIVE ENHANCEMENT VS. GRACEFUL DEGRADATION

47. GRACEFUL DEGRADATION

48. FUNDAMENTAL JAVASCRIPT Graceful Degradation ๏ A holdover from engineering ๏ Build for the latest browsers ๏ Test on older devices ‣ Happens at the end ‣ Accounts for few versions ๏ Expects a poor experience for older browsers ๏ Fixes major issues but little else IN CONTROL 2009 34

49. WEB STANDARDS: FUELING INNOVATION WEB BUILDER 2.0 35

51. PROGRESSIVE ENHANCEMENT FOCUSES ON CONTENT

52. PROGRESSIVE ENHANCEMENT FOCUSES ON CONTENT

53. CONTENT IS WHY WE BUILD WEBSITES AND SHOULD BE OUR CENTRAL FOCUS

56. HOW DOES IT WORK?

58. FUNDAMENTAL JAVASCRIPT Flavorful nugget of content (semantic goodness) IN CONTROL 2009 42

59. FUNDAMENTAL JAVASCRIPT Rich, indulgent design IN CONTROL 2009 43

60. FUNDAMENTAL JAVASCRIPT Sweet interactivity (keeps it from melting in your hands) IN CONTROL 2009 44

62. TECHNOLOGIES APPLIED AS LAYERS

64. WEB STANDARDS: FUELING INNOVATION stuffandnonsense.co.uk/archives/web_standards_trifle.html WEB BUILDER 2.0 48

65. WHY A PEANUT M&M?

66. FUNDAMENTAL JAVASCRIPT The peanut is good for ๏ diabetics IN CONTROL 2009 50

67. FUNDAMENTAL JAVASCRIPT The peanut is good for ๏ diabetics ๏ search engine spiders IN CONTROL 2009 50

68. FUNDAMENTAL JAVASCRIPT The peanut is good for ๏ diabetics ๏ search engine spiders ๏ mobile devices IN CONTROL 2009 50

69. IT’S A BASIC LEVEL OF SUPPORT

70. FUNDAMENTAL JAVASCRIPT The chocolate is good for IN CONTROL 2009 52

71. FUNDAMENTAL JAVASCRIPT The chocolate is good for ๏ diabetics IN CONTROL 2009 52

72. FUNDAMENTAL JAVASCRIPT Rich, chocolaty goodness ๏ some browsers only handle a certain level of CSS ๏ some companies turn off JavaScript IN CONTROL 2009 52

73. IT CAN BE BEAUTIFUL (and progressive)

74. FUNDAMENTAL JAVASCRIPT The candy coating IN CONTROL 2009 54

75. FUNDAMENTAL JAVASCRIPT The candy coating ๏ JavaScript can turn a website into an experience IN CONTROL 2009 54

76. FUNDAMENTAL JAVASCRIPT The candy coating ๏ JavaScript can turn a website into an experience ๏ we can deliver our scripts a la carte IN CONTROL 2009 54

77. PROGRESSIVE ENHANCEMENT WITH JAVASCRIPT

78. RESTRAINT & PLANNING

79. FUNDAMENTAL JAVASCRIPT A long time ago, in a cubicle far, far away... Dear George Lucas, please don’t sue me. Kthxbye. IN CONTROL 2009 57

80. FUNDAMENTAL JAVASCRIPT A long time ago, in a cubicle far, far away... Dear George Lucas, please don’t sue me. Kthxbye. IN CONTROL 2009 57

81. WHAT CAN JAVASCRIPT DO?

82. HOW SHOULD JAVASCRIPT BE USED?

83. PROGRESSIVE ENHANCEMENT REMINDS US TO FOCUS ON THE CONTENT

84. FUNDAMENTAL JAVASCRIPT Back to basics IN CONTROL 2009 60

85. FUNDAMENTAL JAVASCRIPT Back to basics XHTML + HTTP IN CONTROL 2009 60

86. FUNDAMENTAL JAVASCRIPT Back to basics solid foundation IN CONTROL 2009 60

87. FUNDAMENTAL JAVASCRIPT ALL CODE NEEDED TO UNDERSTAND AND USE A SITE SHOULD EXIST BEFORE ANY SCRIPTS RUN IN CONTROL 2009 61

88. FUNDAMENTAL JAVASCRIPT PERIOD. IN CONTROL 2009 61

89. FUNDAMENTAL JAVASCRIPT Consider lala.com IN CONTROL 2009 62

90. FUNDAMENTAL JAVASCRIPT Without JavaScript IN CONTROL 2009 63

91. FUNDAMENTAL JAVASCRIPT Without JavaScript IN CONTROL 2009 63

92. FUNDAMENTAL JAVASCRIPT Without JavaScript Doh! IN CONTROL 2009 63

93. FUNDAMENTAL JAVASCRIPT And looking at the IN CONTROL 2009 64

94. FUNDAMENTAL JAVASCRIPT And looking at the Ug h ! IN CONTROL 2009 64

95. WHAT ABOUT SEARCH?

96. WHAT ABOUT ALTERNATIVE DEVICES?

97. ENTER UNOBTRUSIVE JAVASCRIPT

98. ENTER UNOBTRUSIVE JAVASCRIPT ( ) the cornerstone of Progressive Enhancement with JavaScript

99. FUNDAMENTAL JAVASCRIPT Don’t do this <a href=quot;javascript:someFunction();quot;>some text</a> or <a href=quot;javascript:void(null);quot; onclick=quot;someFunction();quot;>some text</a> or <a href=quot;#quot; onclick=quot;someFunction();quot;>some text</a> IN CONTROL 2009 67

100. FUNDAMENTAL JAVASCRIPT An improvement, but still... <a href=quot;http://offsite.comquot; onclick=quot;newWin( this.href ); return false;quot;> some text</a> IN CONTROL 2009 68

101. FUNDAMENTAL JAVASCRIPT Getting warmer... window.onload = handleExternalLinks; function handleExternalLinks(){ var server = document.location.hostname; var anchors = document.getElementsByTagName(quot;aquot;); var i, href; for( i=0; i < anchors.length; i++ ){ href = anchors[i].href; if( href.indexOf(quot;http://quot; + server) == -1 && href.indexOf(quot;https://quot; + server) == -1 ){ // HREF is not a file on my server anchors[i].onclick = function(){ newWin( this.href ); }; } } } IN CONTROL 2009 69

109. FUNDAMENTAL JAVASCRIPT You’re hot document.getElementsByTagName( 'body' )[0] .onclick = clickDelegator; function clickDelegator( e ){ e = ( e ) ? e : event; var el = e.target || e.srcElement; // external links if( el.nodeName.toLowerCase() == 'a' && el.getAttribute( 'rel' ) == 'external' ){ newWin( el.href ); } } IN CONTROL 2009 70

118. JavaScript CSS

119. FUNDAMENTAL JAVASCRIPT Remember stuff like this? <a href=quot;foo.htmlquot; style=quot;color:blue;quot; onmouseover=quot;this.style.color='red'quot; onmouseout=quot;this.style.color='blue'quot;>Foo</a> IN CONTROL 2009 73

120. FUNDAMENTAL JAVASCRIPT Remember stuff like this? <a href=quot;foo.htmlquot; style=quot;color:blue;quot; onmouseover=quot;this.style.color='red'quot; onmouseout=quot;this.style.color='blue'quot;>Foo</a> Obvisouly, we should be doing this instead: a, a:link, a:visited { color: blue; } a:hover { color: red; } IN CONTROL 2009 73

121. FUNDAMENTAL JAVASCRIPT Isn’t this the same? for( i=0; i<objects.length; i++){ objects[i].style.display = 'none'; } IN CONTROL 2009 74

122. FUNDAMENTAL JAVASCRIPT Small improvement for( i=0; i<objects.length; i++){ objects[i].style.position = 'absolute'; objects[i].style.left = '-999em'; } IN CONTROL 2009 75

123. FUNDAMENTAL JAVASCRIPT Separation CSS: .hidden { position: absolute; left: -999em; } JavaScript: for( i=0; i<objects.length; i++){ objects[i].addClassName( 'hidden' ); } IN CONTROL 2009 76

124. FUNDAMENTAL JAVASCRIPT Maintenance options ๏ external style rules added to your CSS file (by hand) ๏ external CSS file added to the document (by hand) ๏ external CSS file added to the document via script ๏ embedding CSS in the document via script IN CONTROL 2009 77

125. FUNDAMENTAL JAVASCRIPT Option 1: Add by hand At the end of your screen layout CSS ﬁle: /* =START WickedCool Script CSS (do not remove) */ .wicked { color: red; font: bold 4em/2 quot;Comic Sansquot;; } .cool { color: blue; font: bold 4em/2 quot;Comic Sansquot;; } /* =END WickedCool Script CSS */ IN CONTROL 2009 78

126. FUNDAMENTAL JAVASCRIPT Option 2: Include by hand Added to the head of your document: <script type=quot;text/javascriptquot; src=quot;WickedCool.jsquot;></script> <link rel=quot;stylesheetquot; type=quot;text/cssquot; media=quot;screenquot; href=quot;WickedCool.cssquot; /> IN CONTROL 2009 79

127. FUNDAMENTAL JAVASCRIPT Option 3: Scripted include function FindPath( filename ){ var path = false; var scripts = document.getElementsByTagName( 'script' ); for( var i=0; i<scripts.length; i++ ){ if( scripts[i].getAttribute( 'src' ) && scripts[i].getAttribute( 'src' ) .indexOf( filename ) != -1 ){ path = scripts[i].getAttribute( 'src' ) .replace( new RegExp( filename ), '' ); break; } } return path; } IN CONTROL 2009 80

135. FUNDAMENTAL JAVASCRIPT Option 3: Scripted include var WickedCool = { jsFile: 'WickedCool.js', cssFile: 'WickedCool.css', basePath: false, initialize: function(){ // determine the path this.basePath = FindPath( this.jsFile ); // add the CSS file var css = document.createElement( 'link' ); css.setAttribute( 'rel', 'stylesheet' ); css.setAttribute( 'type', 'text/css' ); css.setAttribute( 'media', 'screen' ); css.setAttribute( 'href', this.basePath + this.cssFile ); document.getElementsByTagName( 'head' )[0] .appendChild( css ); // do the rest of the wicked cool stuff } }; IN CONTROL 2009 81

142. FUNDAMENTAL JAVASCRIPT Option 4: Scripted embed function addCSS( styles ){ var el = document.createElement( 'style' ); el.setAttribute( 'type', 'text/css' ); if( el.styleSheet ){ el.styleSheet.cssText = styles; } else { el.appendChild( document.createTextNode( styles ) ); } document.getElementsByTagName( 'head' )[0] .appendChild( el ); } based on the work of Nicholas Zakas IN CONTROL 2009 82

148. FUNDAMENTAL JAVASCRIPT Option 4: Scripted embed var WickedCool = { _css: '.wicked { color: red; ' + ' font: bold 4em/2 quot;Comic Sansquot;; } ' + '.cool { color: blue; ' + ' font: bold 4em/2' quot;Comic Sansquot;; }', initialize: function(){ // add the CSS addCSS( this._css ); // do the rest of the wicked cool stuff } }; based on the work of Nicholas Zakas IN CONTROL 2009 83

153. BUT KEEP IN MIND

154. YOU NEED TO AVOID APPLYING SCRIPT-RELATED STYLES

155. UNTIL YOU KNOW YOUR SCRIPT CAN RUN AND IT HAS INITIALIZED PROPERLY

156. FUNDAMENTAL JAVASCRIPT How do we do that? ๏ make your style rules speciﬁc: .TabInterface-folder { ... } or #TabInterface .tab { ... } #TabInterface .tab.active { ... } IN CONTROL 2009 85

157. FUNDAMENTAL JAVASCRIPT How do we do that? <div id=quot;mainquot; class=quot;tabbedquot;> becomes <div id=quot;mainquot; class=quot;tabbed-onquot;> IN CONTROL 2009 86

158. FUNDAMENTAL JAVASCRIPT How do we do that? Default Activated add “-on” to the class .tabbed .tabbed-on add an activation class .auto-submit .auto-submit.active change the form of the class .replace-me .replaced IN CONTROL 2009 86

160. FUNDAMENTAL JAVASCRIPT Look for methods function someFunction(){ if( !document.getElementsByTagName ) return; // code that uses document.getElementsByTagName() ... } IN CONTROL 2009 88

161. FUNDAMENTAL JAVASCRIPT Look for methods function someFunction(){ if( !document.getElementsByTagName || !document.getElementById ) return; /* code that uses document.getElementsByTagName() and document.getElementById() */ } IN CONTROL 2009 89

162. FUNDAMENTAL JAVASCRIPT Look for elements function someFunction(){ if( !document.getElementsByTagName || !document.getElementsByTagName( 'p' ) ) return; /* code that uses document.getElementsByTagName() and requires the presence of a P element */ ... } IN CONTROL 2009 90

163. FUNDAMENTAL JAVASCRIPT Look for identiﬁed elements function someFunction(){ if( !document.getElementById || !document.getElementById( 'content' ) ) return; // code that requires the presence of #content ... } IN CONTROL 2009 91

164. FUNDAMENTAL JAVASCRIPT Look for objects function someFunction(){ if( typeof( Prototype ) == 'undefined' ) return; // code that uses Prototype ... } IN CONTROL 2009 92

165. FUNDAMENTAL JAVASCRIPT Look for object versions function someFunction(){ if( typeof( jQuery ) == 'undefined' || parseFloat( jQuery.jquery ) < 1.2 ) return; // code that uses jQuery 1.2 or higher ... } IN CONTROL 2009 93

166. FUNDAMENTAL JAVASCRIPT Look before you leap window.onload = function(){ if( document.getElementsByTagName && document.getElementById ){ someFunction(); } }; IN CONTROL 2009 94

167. FUNDAMENTAL JAVASCRIPT PE with JavaScript ๏ Start with the content, then work your way out ๏ Get unobtrusive ๏ Keep some distance between your styles & your scripts ๏ Always wear your detective hat IN CONTROL 2009 95

168. HOW DOES IT ALL COME TOGETHER?

169. FUNDAMENTAL JAVASCRIPT Example 1: Tab Interface IN CONTROL 2009 97

170. FUNDAMENTAL JAVASCRIPT Traditional approach <h1>Pumpkin Pie</h1> <div class=quot;containerquot;> <div class=quot;sectionquot;> <h2>Overview</h2> <img src=quot;pie.jpgquot; alt=quot;quot;> <p>Whether you're hosting a festive party or a casual get-together with friends, our Pumpkin Pie will make entertaining easy!</p> ... </div> ... <ul class=quot;tabsquot;> <li><a href=quot;#quot;>Overview</a></li> <li><a href=quot;#quot;>Ingredients</a></li> <li><a href=quot;#quot;>Directions</a></li> <li><a href=quot;#quot;>Nutrition</a></li> </ul> </div> IN CONTROL 2009 98

174. FUNDAMENTAL JAVASCRIPT No style IN CONTROL 2009 99

175. FUNDAMENTAL JAVASCRIPT A little typography IN CONTROL 2009 100

176. FUNDAMENTAL JAVASCRIPT Typography & color IN CONTROL 2009 101

177. FUNDAMENTAL JAVASCRIPT No style IN CONTROL 2009 102

178. FUNDAMENTAL JAVASCRIPT No style .tabbed IN CONTROL 2009 102

179. FUNDAMENTAL JAVASCRIPT The actual source <h1>Pumpkin Pie</h1> <div class=quot;tabbedquot;> <h2>Overview</h2> <img src=quot;pie.jpgquot; alt=quot;quot; /> <p>Whether you're hosting a festive party or a casual get-together with friends, our Pumpkin Pie will make entertaining easy!</p> ... <h2>Ingredients</h2> <ul> <li>1 (9<abbr title=quot;inchquot;>in</abbr>) unbaked deep dish pie crust</li> <li>½ cup white sugar</li> <li>1 <abbr title=quot;teaspoonquot;>tsp</abbr> ground cinnamon</li> ... </ul> <h2>Directions</h2> ... </div> IN CONTROL 2009 103

180. FUNDAMENTAL JAVASCRIPT The actual source <h1>Pumpkin Pie</h1> <div class=quot;tabbedquot;> <h2>Overview</h2> <img src=quot;pie.jpgquot; alt=quot;quot; /> <p>Whether you're hosting a festive party or a casual get-together with friends, our Pumpkin Pie will make entertaining easy!</p> ... <h2>Ingredients</h2> <ul> <li>1 (9<abbr title=quot;inchquot;>in</abbr>) unbaked deep dish pie crust</li> <li>½ cup white sugar</li> <li>1 <abbr title=quot;teaspoonquot;>tsp</abbr> ground cinnamon</li> ... </ul> <h2>Directions</h2> ... </div> IN CONTROL 2009 103

181. FUNDAMENTAL JAVASCRIPT Understanding the ﬂow IN CONTROL 2009 104

182. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ // Public Properties this.Version = '0.3'; // version // Private Properties var _i = i; // incrementor var _cabinet = el; // the quot;cabinetquot; element (container) var _id = false; // ID of _cabinet var _active = false; // ID of the active quot;folderquot; var _tag = false; // tag we'll split it on // the tab list var _index = document.createElement( 'ul' ); // prototype elements var _els = { li: document.createElement( 'li' ), div: document.createElement( 'div' ) }; // methods to go here }; IN CONTROL 2009 105

187. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ ... function initialize(){ // code to come } function addClassName( e, c ){ var classes = ( !e.className ) ? [] : e.className.split( ' ' ); classes.push( c ); e.className = classes.join( ' ' ); } function removeClassName( e, c ){ var classes = e.className.split( ' ' ); for( var i=classes.length-1; i>=0; i-- ){ if( classes[i] == c ) classes.splice( i, 1 ); } e.className = classes.join( ' ' ); } // start it up initialize(); }; IN CONTROL 2009 106

192. FUNDAMENTAL JAVASCRIPT THE CODE function TabInterface( el, i ){ function initialize(){ // set the id _id = el.getAttribute( 'id' ) || 'folder-' + _i; if( !el.getAttribute( 'id' ) ) el.setAttribute( 'id', _id ); // trim whitespace var node = _cabinet.firstChild; while( node ){ var nextNode = node.nextSibling; if( node.nodeType == 3 && !/S/.test( node.nodeValue ) ) _cabinet.removeChild( node ); node = nextNode; } } ... }; IN CONTROL 2009 107

193. FUNDAMENTAL JAVASCRIPT THE CODE function TabInterface( el, i ){ function initialize(){ // set the id _id = el.getAttribute( 'id' ) || 'folder-' + _i; if( !el.getAttribute( 'id' ) ) el.setAttribute( 'id', _id ); // trim whitespace var node = _cabinet.firstChild; while( node ){ var nextNode = node.nextSibling; if( node.nodeType == 3 && !/S/.test( node.nodeValue ) ) _cabinet.removeChild( node ); node = nextNode; } } ... }; IN CONTROL 2009 107

194. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ function initialize(){ ... // find the first heading var headers = [ 'h1', 'h2', 'h3', 'h4', 'h5', 'h6' ]; var hLen = headers.length; for( var i=0; i<hLen; i++ ){ if( _cabinet.firstChild.nodeName.toLowerCase() == headers[i] ){ _tag = headers[i]; break; } } } ... }; IN CONTROL 2009 108

195. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ function initialize(){ ... // establish the folders var rexp = new RegExp( '<(' + _tag + ')', 'ig' ); var arr = _cabinet.innerHTML.replace( rexp, quot;||||<$1quot; ).split( '||||' ); arr.shift(); _cabinet.innerHTML = ''; removeClassName( _cabinet, 'tabbed' ); addClassName( _cabinet, 'tabbed-on' ); } ... }; IN CONTROL 2009 109

196. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ function initialize(){ ... for( var k=0, aLen = arr.length; k<aLen; k++ ){ // build the div var folder = _els.div.cloneNode( true ); addClassName( folder, 'folder' ); folder.setAttribute( 'id', _id + '-' + k ); folder.innerHTML = arr[k]; _cabinet.appendChild( folder ); // build the tab var tab = _els.li.cloneNode( true ); tab.folder = folder.getAttribute( 'id' ); tab.setAttribute( 'id', tab.folder + '-tab' ); tab.onclick = swap; // set the action var heading = folder.getElementsByTagName( _tag )[0]; tab.innerHTML = heading.innerHTML; addClassName( heading, 'hidden' ); _index.appendChild( tab ); } } ... IN CONTROL 2009 110

200. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ function initialize(){ ... for( var k=0, aLen = arr.length; k<aLen; k++ ){ ... // active? if( k == 0 ){ addClassName( folder, 'visible' ); _active = folder.getAttribute( 'id' ); addClassName( tab, 'active-tab' ); } } // add the index _index.className = 'tab-list'; _cabinet.appendChild( _index ); } ... }; IN CONTROL 2009 111

201. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ function initialize(){ ... for( var k=0, aLen = arr.length; k<aLen; k++ ){ ... // active? if( k == 0 ){ addClassName( folder, 'visible' ); _active = folder.getAttribute( 'id' ); addClassName( tab, 'active-tab' ); } } // add the index _index.className = 'tab-list'; _cabinet.appendChild( _index ); } ... }; IN CONTROL 2009 111

202. FUNDAMENTAL JAVASCRIPT The code function TabInterface( el, i ){ ... function swap( e ){ e = ( e ) ? e : event; var tab = e.target || e.srcElement; removeClassName( document.getElementById( _active + '-tab' ), 'active-tab' ); removeClassName( document.getElementById( _active ), 'visible' ); addClassName( tab, 'active-tab' ); addClassName( document.getElementById( tab.folder ), 'visible' ); _active = tab.folder; } ... }; IN CONTROL 2009 112

206. FUNDAMENTAL JAVASCRIPT Greater ﬂexibility function TabInterface( el, i ){ function initialize(){ ... for( var k=0, aLen = arr.length; k<aLen; k++ ){ ... var heading = folder.getElementsByTagName( _tag )[0]; tab.innerHTML = heading.innerHTML; if( heading.getAttribute( 'title' ) ){ addClassName( heading, 'hidden' ); tab.innerHTML = heading.getAttribute( 'title' ) _index.appendChild( tab ); } else { ... tab.innerHTML = heading.innerHTML; } addClassName( heading, 'hidden' ); } } ... _index.appendChild( tab ); }; ... } } ... }; IN CONTROL 2009 113

207. FUNDAMENTAL JAVASCRIPT Greater ﬂexibility function TabInterface( el, i ){ function initialize(){ ... for( var k=0, aLen = arr.length; k<aLen; k++ ){ ... var heading = folder.getElementsByTagName( _tag )[0]; if( heading.getAttribute( 'title' ) ){ tab.innerHTML = heading.getAttribute( 'title' ) } else { tab.innerHTML = heading.innerHTML; addClassName( heading, 'hidden' ); } _index.appendChild( tab ); ... } } ... }; IN CONTROL 2009 113

208. FUNDAMENTAL JAVASCRIPT Running it // Load up TabInterface if( document.getElementById && document.getElementsByTagName && document.createElement ){ var cabinets = Array(); addDOMLoadEvent( function(){ var collection = document.getElementsByTagName( '*' ); for( var i=0, cLen = collection.length; i<cLen; i++ ){ if( collection[i] && /s*tabbeds*/.test( collection[i].className ) ){ cabinets.push( new TabInterface( collection[i], i ) ); } } } ); } IN CONTROL 2009 114

212. FUNDAMENTAL JAVASCRIPT The full experience IN CONTROL 2009 115

213. QUESTIONS?

214. FUNDAMENTAL JAVASCRIPT Example 2: Collapsing Form IN CONTROL 2009 117

215. FUNDAMENTAL JAVASCRIPT Collapsing Form as HTML IN CONTROL 2009 118

216. FUNDAMENTAL JAVASCRIPT Collapsing Form with CSS IN CONTROL 2009 119

219. FUNDAMENTAL JAVASCRIPT HTML hooks IN CONTROL 2009 122

220. FUNDAMENTAL JAVASCRIPT HTML hooks form.collapsing IN CONTROL 2009 122

221. FUNDAMENTAL JAVASCRIPT HTML hooks fieldset.optional IN CONTROL 2009 122

222. FUNDAMENTAL JAVASCRIPT Understanding the ﬂow IN CONTROL 2009 123

223. FUNDAMENTAL JAVASCRIPT The code var Easy = { addClassName: function( e, c ){ var classes = ( !e.className ) ? [] : e.className.split( ' ' ); classes.push( c ); e.className = classes.join( ' ' ); }, removeClassName: function( e, c ){ var classes = e.className.split( ' ' ); for( var i=classes.length-1; i>=0; i-- ){ if( classes[i] == c ) classes.splice( i, 1 ); } e.className = classes.join( ' ' ); }, hasClassName: function( e, c ){ var classes = e.className.split( ' ' ); for( var i=classes.length-1; i>=0; i-- ){ if( classes[i] == c ) return true; } return false; } }; IN CONTROL 2009 124

228. FUNDAMENTAL JAVASCRIPT The code var CollapsingForm = Class.create(); CollapsingForm.prototype = { link: document.createElement( 'a' ), linkText: [ document.createTextNode( 'More options' ), document.createTextNode( 'Fewer options' ) ], hidden: [], state: false, id: false, }; IN CONTROL 2009 125

231. FUNDAMENTAL JAVASCRIPT The code CollapsingForm.prototype = { ... initialize: function( form, i ){ // set the id this.id = i; // get the fieldsets var coll = form.getElementsByTagName( 'fieldset' ); // look for hiddens var hide = false; for( var i=coll.length-1; i>=0; i-- ){ if( coll[i].className.indexOf( 'hide-me' ) != -1 ){ hide = true; Easy.addClassName( coll[i], 'hidden' ); Easy.removeClassName( coll[i], 'hide-me' ); this.hidden.push( coll[i] ); } } // more to come } }; IN CONTROL 2009 126

235. FUNDAMENTAL JAVASCRIPT The code CollapsingForm.prototype = { ... initialize: function( form, i ){ ... // stop if no hiddens if( hide === false ) return; this.state = 'less'; // create & append the link to the first fieldset this.link = document.createElement( 'a' ); this.link.className = 'show-hide-link'; this.link.setAttribute( 'href', '#' ); Event.observe( this.link, 'click', this.toggle.bindAsEventListener( this ), false ); this.link.appendChild( this.linkText[0] ); coll[0].appendChild( this.link ); Easy.addClassName( form, 'collapsible' ); Easy.removeClassName( form, 'collapsing' ); } }; IN CONTROL 2009 127

239. FUNDAMENTAL JAVASCRIPT The code CollapsingForm.prototype = { initialize: function( form, i ){ ... }, toggle: function(){ if( this.state == 'less' ){ this.showMore(); } else { this.showLess(); } }, showMore: function(){ // code to come }, showLess: function(){ // code to come } }; IN CONTROL 2009 128

240. FUNDAMENTAL JAVASCRIPT The code CollapsingForm.prototype = { initialize: function( form, i ){ ... }, toggle: function(){ if( this.state == 'less' ){ this.showMore(); } else { this.showLess(); } }, showMore: function(){ // code to come }, showLess: function(){ // code to come } }; IN CONTROL 2009 128

241. FUNDAMENTAL JAVASCRIPT The code CollapsingForm.prototype = { ... showMore: function(){ for( var i=0; i<this.hidden.length; i++ ){ Easy.removeClassName( this.hidden[i], 'hidden' ); } this.link.replaceChild( this.linkText[1], this.link.childNodes[0] ); this.state = 'more'; }, showLess: function(){ for( var i=0; i<this.hidden.length; i++ ){ Easy.addClassName( this.hidden[i], 'hidden' ); } this.link.replaceChild( this.linkText[0], this.link.childNodes[0] ); this.state = 'less'; } }; IN CONTROL 2009 129

244. FUNDAMENTAL JAVASCRIPT Collapsing Form with JS IN CONTROL 2009 130

245. QUESTIONS?

246. WORKING WITH LIBRARIES

247. FUNDAMENTAL JAVASCRIPT Popular Libraries ๏ jQuery (jquery.com) ๏ Prototype (prototypejs.org) & Scriptaculous (script.aculo.us) ๏ YUI (developer.yahoo.com/yui) ๏ Dojo (dojotoolkit.org) ๏ Spry (labs.adobe.com/technologies/spry) ๏ MooTools (mootools.net) ๏ MochiKit (mochikit.com) IN CONTROL 2009 133

248. FUNDAMENTAL JAVASCRIPT Popular Libraries ๏ jQuery - fast & easy to write, selector-based ๏ Prototype & Scriptaculous - powerful, Ruby-like ๏ YUI - powerful, backed by Yahoo! ๏ Dojo - powerful, backed by IBM ๏ Spry - supported in Dreamweaver, backed by Adobe ๏ MochiKit - powerful, Python-like IN CONTROL 2009 134

249. FUNDAMENTAL JAVASCRIPT Popular Libraries ๏ jQuery - fast & easy to write, selector-based ๏ Prototype & Scriptaculous - powerful, Ruby-like ๏ YUI - powerful, backed by Yahoo! IN CONTROL 2009 134

250. FUNDAMENTAL JAVASCRIPT Getters 2.0 ๏ jQuery: ‣ $(selector) ‣ $(selector).attr(attribute) ๏ Prototype: ‣ $(id) or $$(selector) ‣ $$(selector).readAttribute(attribute) ๏ YUI: ‣ YAHOO.util.Dom.get(id) or YAHOO.util.Selector.query(selector) ‣ YAHOO.util.Dom.getAttribute(element, attribute) IN CONTROL 2009 135

251. FUNDAMENTAL JAVASCRIPT Setters 2.0 ๏ jQuery: ‣ $(x).text(text) or $(x).html(html) or $(x).append([el|text]) ‣ $(x).attr([attr, value|map]) ๏ Prototype: ‣ $(x).insert([text|element]) // after by default ‣ $(x).writeAttribute([attr, value|map]) ๏ YUI: ‣ YAHOO.util.Dom.insertAfter( [str|el], reference) ‣ YAHOO.util.Dom.addClass(el, class) IN CONTROL 2009 136

252. LET’S REVISIT OUR FIRST EXAMPLE

Fundamental JavaScript [In Control 2009]

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