Ajax Patterns And Best Practices (2006)

■P

Parent implementation, 356

Parent interface, implementing, REST-Based Model View Controller pattern

implementing asynchronous Parent interface instance, 359–360

implementing Base Class, 357–358

implementing synchronous Parent, 360–361

overview, 357

ParentBase class, 357

ParentBase.processRequest method, 361

parentElement property, HTML element, 69

parseElement function, 215, 219

parseHeaders method, 366

Passive caching, 81

password property, 237

pattern implementation, 221

permission exception, 164

Permutations pattern, 150, 233, 269, 277, 337

applicability, 116

architecture. See also book application example

overview, 116

resource separation from representation, 117–118

using cookies and HTTP authentication to authorize access, 119–122

associated patterns, 116

highlights of, 150–151

implementation, rewriting, 293–295

purpose of, 111–114, 116

rewriting URLs

generating content, 134

implementing details of, 130–134

overview, 128–129

using Accept header on client side, 135

shopping cart application example. See also shopping cart application example

PermutationsServlet class, 365, 367

Persistent Communications pattern, 116, 159, 203, 304–305, 308, 335, 337, 341, 362–363

applicability, 227–228 architecture

and change in Internet architecture, 228–231

implementing polling solution, 231–232 overview, 228

associated patterns, 228

calling ServerCommunicator intelligently, 244–246

implementation

global status resource example, 233–248 overview, 233

performance considerations, 262 presence detection example, 248–252 server push example, 252–261 version numbers and updates, 262

implementing ClientCommunicator, 236–241

implementing HTML page, 233–236

implementing ServerCommunicator, 241–244

implementing server-side monitoring process, 247–248

overview, 233

pattern highlights, 262–263 purpose of, 225–227

Persistent Communications patterns, 339 Personal Information grouping, 211 plain-vanilla web application, 16 platform-neutral languages, 14

POP3 (Post Office Protocol), 231 PopupDialogBox function, 189 PopupDialogbox function, 192 Post Office Protocol (POP3), 231 postURL data member, 285 predictive cache, 91, 109 Predictive caching, 82 preferredTypes property, 237

380■I N D E X

prefetch function, 93, 95–96, 98 presence detection

authenticating user, 248 overview, 248

updating ServerCommunicator, 248–252 presentation function, 161, 177 Presentation functionality, 196 presentation parameter, 176 previousSibling property, HTML element, 69 price comparison services, 111

prime number algorithm, 308 PrimeNumber tag, 321 PrimeNumberHandler class, 318–319 PrimeNumberHandler directory, 308

PrimeNumberHandler.ProcessRequest method, 320

PrivateLoop function, 239, 242 processElement function, 216, 219 ProcessRequest method, 319 processRequest method, 352, 358, 361, 363 processResults method, 349

ProcessTasks method, 327 prop property, 206 prototype property, 37, 239

prototype.instances property, 239 Proxy pattern, 82, 338

■Q

q value, 126

Query variable, Amazon.com, 347 queryIdentifier variable, 350

■R

reactional server, 247 Read-mostly data, 233 readyState property, 33, 43

reference property, dynamicFiller variable, 76 Remote Procedure Calls (RPCs), 25 Representation interface, 364

Representation Morphing pattern, 224, 268, 283. See also Representation Morphing pattern implementation

applicability, 202–203

architecture

basic theory, 204–205

defining blocks of state, 206–211

overview, 203–204

why pattern is not HTML component, 205–206

associated patterns, 203

pattern highlights, 224

purpose of, 197–202

Representation Morphing pattern implementation, 221–224

implementing framework, 211–213

implementing representation reference points

JavaScript representation reference point, 213–218

overview, 213

XSLT representation reference point, 218–220

overview, 211

Representational State Transfer (REST)

architecture style, 11

representation.canProcess method, 366

_representations data member, 366

req.getParameter method, 104

Request interface, 352

request parameter, 293

request.complete method, 291

request.getInputStream method, 242

resetAssignedHashCode method, 90

Resolve method, 141

Resource method, IUserIdentificationResolver interface, 137

Resource to Representation layer, 281

_resourceStateContentType data member, 296

response parameter, 293

responseText property, 23, 26, 69

responseXML parameter, 314

responseXML property, 26, 69

REST (Representational State Transfer)

architecture style, 11

REST data, 21–22

REST theory, 19–21

REST-Based Model View Controller pattern, 181. See also REST-Based Model View Controller pattern implementation

applicability, 335

architecture

defining appropriate resource, 338–340

defining calling interface, 340–343

defining data format foundation and extras, 343–346

overview, 336–338

associated patterns, 335–336

pattern highlights, 367–368

purpose of, 333–334

REST-Based Model View Controller pattern implementation

creating search engine client infrastructure

defining abstracted REST-Based Model View Controller pattern, 352–353

implementing search abstractions, 353–356

overview, 350–352

handling asynchronous search

implementing servlet-based Permutations pattern, 364–366

overview, 361, 364

posting query, 361–363

processing request, 367

retrieving result, 363–364

implementing Parent

implementing asynchronous Parent interface instance, 359–360

implementing Base Class, 357–358

implementing synchronous Parent, 360–361

overview, 357 implementing search

overview, 346

using Amazon.com for searching, 346–349

using Google for searching, 349–350 overview, 346, 357

Result element, XML, 312

Result interface, 352

_results data member, 326, 330, 359 return keyword, 168

rewrite component, 128 Rewriter interface instance, 294 rewriter parameter, 295 rewriting URLs

generating content, 134 implementing details of, 130–134 overview, 128–129

using Accept header on client side, 135 rich-client local installation, 14–15 rich-client web services, 15–16

root resource definition URL, 258 root URL, 118

RouterASPNet class, 130 routing component, 127

RPCs (Remote Procedure Calls), 25 runat attribute, 254

runFilter method, 293, 298 runIt function, 238 Runnable interface, 353

_runningThreads data member, 358 RunThreadedTasks method, 321, 326

■S

same origin policy, 23, 333 saveForm method, 283, 288–289 saveState method, 283, 290 screen scraping, 111

382■I N D E X

script element, 213

script tags, 30, 93, 235, 311 script-defined passive cache, 95 /search identifier, 339

/search URL, 181 SearchBuilder class, 354, 361 SearchRequest interface, 356 SearchResult interface, 356

Secure Shell (SSH) console window, 134 send method

ClientCommunicator, 240 XMLHttpRequest, 25

serialization, of XML documents, 323 Serialization.Generate method, 324 Serialization.Parse method, 324 Serializer implementation, 325 server framework, 109

server push implementation

completing ServerCommunicator, 256–261

overview, 252 specifying URLs

overview, 253

using hard-coded URL, 253 using HTTP redirection, 255–256 using user identification, 253–254

server2client property, 237 ServerCommunicator

calling intelligently, global status resource example, 244–246

completing, server push example, 256–261

implementing, global status resource example, 241–244

updating, 248–252 ServerCommunicator type, 232 ServerPush class, 257 server-side caching, 86–88 server-side code, 91 server-side framework, 88 server-side libraries, 145

server-side monitoring process, 247–248 service method, 250, 259

Servlet interface, 250 Session variable, 147, 362 setAttribute method, 223 SetCacheability method, 83

setConfiguration method, 295 Set-Cookie HTTP header, 146 SetExpires method, 83 setInterval method, 45 setQueryString method, 349

setRequestHeader method, XMLHttpRequest class, 25, 97, 135

setRootPath method, 103 setTimeout method, 44, 238–239 shopping cart application example

defining user identification interfaces, 136–137

HTTP authentication

authenticating when not necessary, 143–145

how functions, 137–139 implementing, 139–143 overview, 137

HTTP cookies

generating cookie, 145–146 how client manages, 146 identifying user with, 146–148 overview, 145

implementing shopping cart, 148–150 overview, 135–136

ShowContent function, 218 signature variable, 348

Signature.generateSignature method, 348 Simple Object Access Protocol (SOAP), 15, 335 single-shot display strategy, 226 SingleThreadModel interface, 246 Slashdot, 199

sleep() method, Thread class, 246 snippet content, 344

SOAP (Simple Object Access Protocol), 15, 335 Sort method, Array class, 131

span elements, 215, 217, 219–220, 313 span HTML tags, 208

span innerHTML property, 216–217 span tag, 22, 73

spanElement variable, 314 spanElement.innerHTML property, 314 Specialization interface, 351

src attribute, 70, 72, 74, 235 srcElement property, 167

SSH (Secure Shell) console window, 134 stale result, 314

StartIt function, 44

StartItNonEnding function, 45

State Filter layer, 281

state identification, 204 state identifier, 290

State interface instance, 301 state keyword, 277, 298

State Navigation pattern, 163, 181, 203, 319. See also State Navigation pattern implementation

applicability, 267 architecture

extending solution for web application, 272–276

managing state at protocol level, 277–280

moving toward ideal solution from user’s perspective, 268–270, 272

overview, 268 associated patterns, 268 pattern highlights, 301 purpose of, 265–267

State Navigation pattern implementation overview, 280–281

processing requests on client

details of State Navigation, 284–291 overview, 281–282

using State Navigation from HTML page, 282–284

processing requests on server

HTTP filters, when and how to trigger, 291–293

implementing State layer, 295–301 overview, 291

rewriting Permutations pattern implementation, 293–295

state object, 140, 215–216 state property, 177 /state URL, 181

StateController variable, 284, 288 StateController.loadState( ) method, 283 StateController.saveState( ) method, 283 StateFilter class implementation, 301 StateIdentifier property, 300 _stateManager data member, 296 StateManager interface, 300 _stateManager variable, 300 state.setBuffer method, 299

static GUI link, 153

static HTTP validation, 88–89, 103–104 static method, 118

static programming techniques, 206 static random transaction identifier, 313 static URL, 88

static user interfaces, 200 static validation, 88

staticHashCode data member, 90 status parameter, 95

status property, 26 status updates, 227 statusText property, 26

Stream Aggregator pattern, 82 style property, HTML element, 69 super.processRequest method, 361 super.service method, 250

switch statement, 32 synchronization techniques, 360 synchronized keyword, 359 synchronous form, 335

384■I N D E X

synchronous interface, 343 synchronous requests, 342 SynchronousParent class, 360 SynchronousServlet class, 367

■T

tabIndex property, HTML element, 69 table element, 167, 311

tagName property, HTML element, 69 tail variable, 298

target attribute, 163 target property, 167

task implementation, 307 Task Manager implementation

calling interface implementations multiple types, 322–325 overview, 318–320

retrieving results, 321 sending tasks, 320–321 defining interfaces, 316–317 implementing task, 330–331

overview, 316

packaging implementations, 317–318

understanding details of Task Manager, 325–330

task transaction identifier, 313 task variable, 327 task.Execute method, 327 taskManager parameter, 316 taskManager variable, 320

taskManager.GetResultWait method, 321 TaskManagerImpl class, 325

td element, 73, 167 tempReference variable, 240 TestTable button, 65 text-based browsers, 112 TextState class, 181

text/xml MIME type, 126, 344

this keyword, 37 this object, 327 this variable, 95

thisReference.verifyWindowName method, 288

this.verify method, 286 this.xmlhttp variable, 39 thrd variable, 361

_thread data member, 325, 327 ThreadPool, 328

tilde character (~), 119–120 title attribute, 218

Title child tag, 124 transaction identifier, 307, 312

TransactionIdentifier child element, 322 _transactionIdentifier data member, 331 TransactionIdentifier element, XML, 312 transactionIdentifier parameter, 315 TransactionIdentifier property, 316, 331 TriggerFilter class, 293, 295

try catch exception block, 98 type attribute, 323

■U

Uniform Resource Locators. See URLs URL /account, 118

url parameter, 23

URL request variables, 340

URL-encode, 348

URLRewriterASPNet class, 129

URLs (Uniform Resource Locators), 21, 123

chunking, 69–70, 72

defining, 123–125 rewriting, 122, 128

generating content, 134 implementing details of, 130–134 overview, 128–129

using Accept header on client side, 135

specifying overview, 253

using hard-coded URL, 253 using HTTP redirection, 255–256 using user identification, 253–254

UseIt.Method, 118 user data member, 249

user identification, 251, 253–254

user identification interfaces, 136–137 User Identification layer, 281

user interaction link, 156 user interface toolkit, 24 user variable, 259 userComplete method, 98

user-friendly component updates, 201 UserIdentification constructor, 140 userIdentification data member, 249 UserIdentification interface, 248 UserIdentificationResolver interface, 248 userIdentifier property, 257

username property, 237 _users data member, 249 UserState class, 257 UserState object instance, 259

■V

ValidationLibrarianServlet class, 108 value attribute, 204

value variable, 206, 238 variable counter, 44 variable instance, 284 version property, 257 versionTracker property, 245

■W

W3C (World Wide Web Consortium), 62 W3C HTML Document Object Model, 62 wait function, 360

WAP (Wireless Access Protocol), 112 web application framework, 20

Web Services Description Language (WSDL),

16, 349

WhoisOnline class, 248, 250 wiki, 203

Wikipedia project, 1 window.setTimeout method, 44, 238 window.XMLHttpRequest object, 29 Wireless Access Protocol (WAP), 112 World Wide Web Consortium (W3C), 62 WriteRedirection method, 134, 295

defaultRewriter, 131 IRewriter interface, 129

URL rewriter component, 129, 131

WSDL (Web Services Description Language),

16, 349

WWW-Authenticate, HTTP header, 139

■X

XHTML, 59

XML (Extensible Markup Language), benefits of, 12

XML schemas, 322

XMLContent type, addRepresentation method, 367

xmlhttp variable, 23, 30 XMLHttpRequest

calling domains other than serving domain

Apple Safari, 46

Microsoft Internet Explorer, 47–49

Mozilla Firefox, 49–51

overview, 45–46

implementing asynchronous calling mechanism

Asynchronous class, 36–37, 39–43 modified Ajax application, 34–36 overview, 34

problem of multiple requests and multiple callbacks, 37–38

providing feedback from asynchronous requests, 43–45

overview, 34

386■I N D E X

XMLHttpRequest class, 28–29, 34, 58–59, 69, 91, 142, 146, 159, 163, 173, 255, 274, 277, 283, 333

XMLHttpRequest instance, 232 XMLHttpRequest type, 19, 51, 270 XMLHttpRequest.open method, 96 xmlhttp.setRequestHeader method, 288 XMLIterateElements function, 288, 291, 324 xmlParse function, 220

X-Page-State, HTTP header, 277 _XPageState data member, 296 X-Page-State HTTP header, 275 X-Page-Window-Name, HTTP header, 277 X-query-identifier, HTTP header, 343

xsd.exe command-line utility, 323

xsl, 220

template element, XML, 220

text tags, 220

XSLT (Extensible Stylesheet Language

Transformations), 60, 218

XSLT representation reference point, 218–220

xsltFromSpan identifier, 219

xsltProcess function, 220

X-Version-ID, HTTP header, 245

■Z

zooming controls, MapQuest application, 79