Pro JavaScript for Web Apps pdf - EBook Free Download

More documents

Recommendations

Info

CHAPTER 9 WRITING BETTER JAVASCRIPTUnderstanding Directly Resolved DependenciesThe tiny web app works because jQuery has been loaded long before I call the mapProducts function. Thesituation would be different if I rewrote the web app to use a different toolkit. Most programmers do thesame thing when they first understand that assumed dependencies are a problem: they assume controlof the situation and take direct action to fix it. Listing 9-9 shows a typical solution.Listing 9-9. Taking Direct Action to Resolve Assumed Dependencies(function() {function createNamespace(namespace) {...code removed for brevity...};var utilsNS = createNamespace("cheeselux.utils");Modernizr.load({load: 'jquery-1.7.1.js',complete: function() {utilsNS.mapProducts = function(func, data, indexer) {$.each(data, function(outerIndex, outerItem) {$.each(outerItem[indexer], function(itemIndex, innerItem) {func(innerItem, outerItem);});});}}})...code removed for brevity...})();In this listing, I have taken responsibility for resolving my dependency on jQuery by usingModernizr to load it before creating my mapProducts function. (The load property in a Modernizr.loadobject specifies that the JavaScript file should always be loaded.)In doing this, I have transformed an assumed dependency into a directly resolved dependency. Adirectly resolved dependency is when I rely on another JavaScript library and I take direct action to makemy code work, usually by loading the library myself.Understanding the Problems Caused by Resolving a DependencyDirectly resolving a dependency causes a lot of problems. First, I created an assumed dependency onModernizr to ensure that jQuery is loaded, which isn’t a huge step forward. But the real damage is that Ihave made sure that the mapProducts function works; however, in doing so, I have undermined thestability of the web app itself.To see the problem, load the web app, and reload the page a few times. There are two issues. If theweb app works, you have encountered just the least serious one, which is that the jQuery library hasbeen loaded twice. You can see this in the browser developer tools or in the console output from theNode.js server that prints out each URL that is requested. Here is the list of files loaded by the web app asreported by the server, with annotations to highlight the two loads for jQuery:240www.it-ebooks.info
CHAPTER 9 WRITING BETTER JAVASCRIPTThe "sys" module is now called "util". It should have a similar interface.Ready on port 80Ready on port 81GET request for /example.htmlGET request for /jquery.mobile-1.0.1.cssGET request for /styles.mobile.cssGET request for /jquery-1.7.1.jsGET request for /jquery.mobile-1.0.1.jsGET request for /knockout-2.0.0.jsGET request for /modernizr-2.0.6.jsGET request for /utils.jsGET request for /products.jsonGET request for /jquery-1.7.1.jsGET request for /images/ajax-loader.png
Page 1 and 2:
www.it-ebooks.info
Page 3 and 4:
Contents at a Glance• About the A
Page 5 and 6:
CHAPTER 1 GETTING READYWhat Do You
Page 7 and 8:
CHAPTER 1 GETTING READYChapter 8:
Page 9 and 10:
CHAPTER 1 GETTING READYWould you l
Page 11 and 12:
CHAPTER 1 GETTING READYThe server-
Page 13 and 14:
CHAPTER 1 GETTING READYListing 1-3
Page 15 and 16:
CHAPTER 1 GETTING READY{{each prop
Page 17 and 18:
C H A P T E R 2Getting StartedIn th
Page 19 and 20:
CHAPTER 2 GETTING STARTEDListing 2
Page 21 and 22:
CHAPTER 2 GETTING STARTED• Cauti
Page 23 and 24:
CHAPTER 2 GETTING STARTEDIn Listin
Page 25 and 26:
Page 27 and 28:
CHAPTER 2 GETTING STARTEDHandling
Page 29 and 30:
CHAPTER 2 GETTING STARTEDFigure 2-
Page 31 and 32:
Page 33 and 34:
CHAPTER 2 GETTING STARTED($0)Total
Page 35 and 36:
CHAPTER 2 GETTING STARTED})}$('.la
Page 37 and 38:
CHAPTER 2 GETTING STARTEDOnce agai
Page 39 and 40:
CHAPTER 2 GETTING STARTED...$('spa
Page 41 and 42:
CHAPTER 2 GETTING STARTEDFigure 2-
Page 43 and 44:
CHAPTER 2 GETTING STARTED...This c
Page 45 and 46:
CHAPTER 2 GETTING STARTED• Tip O
Page 47 and 48:
CHAPTER 2 GETTING STARTEDSummaryAs
Page 49 and 50:
CHAPTER 3 ADDING A VIEW MODELCreat
Page 51 and 52:
CHAPTER 3 ADDING A VIEW MODEL$('#b
Page 53 and 54:
CHAPTER 3 ADDING A VIEW MODELThe o
Page 55 and 56:
CHAPTER 3 ADDING A VIEW MODEL};{id
Page 57 and 58:
CHAPTER 3 ADDING A VIEW MODELfunct
Page 59 and 60:
CHAPTER 3 ADDING A VIEW MODELFigur
Page 61 and 62:
CHAPTER 3 ADDING A VIEW MODELitem.
Page 63 and 64:
CHAPTER 3 ADDING A VIEW MODEL $()T
Page 65 and 66:
CHAPTER 3 ADDING A VIEW MODELimmed
Page 67 and 68:
CHAPTER 3 ADDING A VIEW MODELYou c
Page 69 and 70:
CHAPTER 3 ADDING A VIEW MODELmapPr
Page 71 and 72:
CHAPTER 3 ADDING A VIEW MODELAs I
Page 73 and 74:
CHAPTER 3 ADDING A VIEW MODELFigur
Page 75 and 76:
CHAPTER 3 ADDING A VIEW MODEL});if
Page 77 and 78:
C H A P T E R 4Using URL RoutingIn
Page 79 and 80:
CHAPTER 4 USING URL ROUTINGwe requ
Page 81 and 82:
CHAPTER 4 USING URL ROUTINGAdding
Page 83 and 84:
CHAPTER 4 USING URL ROUTINGApplyin
Page 85 and 86:
CHAPTER 4 USING URL ROUTINGConsoli
Page 87 and 88:
CHAPTER 4 USING URL ROUTINGListing
Page 89 and 90:
CHAPTER 4 USING URL ROUTINGThe app
Page 91 and 92:
CHAPTER 4 USING URL ROUTINGurl att
Page 93 and 94:
CHAPTER 4 USING URL ROUTINGThe sel
Page 95 and 96:
CHAPTER 4 USING URL ROUTING• Not
Page 97 and 98:
CHAPTER 4 USING URL ROUTINGcrossro
Page 99 and 100:
CHAPTER 4 USING URL ROUTINGRestori
Page 101 and 102:
CHAPTER 4 USING URL ROUTINGAdding
Page 103 and 104:
CHAPTER 4 USING URL ROUTING}"#sele
Page 105 and 106:
CHAPTER 4 USING URL ROUTINGFigure
Page 107 and 108:
CHAPTER 4 USING URL ROUTING• Tip
Page 109 and 110:
C H A P T E R 5Creating Offline Web
Page 111 and 112:
CHAPTER 5 CREATING OFFLINE WEB APP
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
C H A P T E R 6Storing Data in the
Page 139 and 140:
CHAPTER 6 STORING DATA IN THE BROW
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
C H A P T E R 7Creating Responsive
Page 171 and 172:
CHAPTER 7 CREATING RESPONSIVE WEB
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190: CHAPTER 7 CREATING RESPONSIVE WEB
Page 195 and 196: C H A P T E R 8Creating Mobile Web
Page 197 and 198: CHAPTER 8 CREATING MOBILE WEB APPS
Page 229 and 230: C H A P T E R 9Writing Better JavaS
Page 231 and 232: CHAPTER 9 WRITING BETTER JAVASCRIP
Page 239: CHAPTER 9 WRITING BETTER JAVASCRIP
Page 261 and 262: • INDEXHTML5 local storage featur
Page 263 and 264: • INDEXURL routing, CheeseLux (co
Page 265 and 266: Pro JavaScript for Web AppsCopyrigh
Page 267 and 268: Contents• About the Author.......
Page 269 and 270: • CONTENTS• Chapter 3: Adding a
Page 271 and 272: • CONTENTSUsing Persistence in th
Page 273 and 274: • CONTENTSAdding Tests for a Modu
Page 275 and 276: About the Technical Reviewer RJ Owe
show all

Pro JavaScript for Web Apps pdf - EBook Free Download

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?