Distributed Data Applications with ASP.NET

801 Pages·2004·24.18 MB·English

by  Alex Homer

Distributed
Data Applications
with ASP.NET,
Second Edition
ALEX HOMER AND DAVID SUSSMAN
APress Media, LLC
Distributed Data Applications with ASP.NET, Second Edition
Copyright © 2004 by Alex Homer and David Sussman
Originally published by Apress in 2004
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ISBN 978-1-59059-318-9 ISBN 978-1-4302-0661-3 (eBook)
DOI 10.1007/978-1-4302-0661-3
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Contents at a Glance
About the Authors ............................................................................................ xiii
Introduction ........................................................................................................ xv
Chapter 1 The Distributed Application .............................................. 1
Chapter 2 Components and Data Access .............................................. 53
Chapter 3 Accessing XML Documents ................................................... 109
Chapter 4 The Application Plumbing ................................................ 143
Chapter 5 Working with Down-Level Clients ................................. 199
Chapter 6 Working with Rich Clients .............................................. 261
Chapter 7 Remoting to .NET Clients ................................................ 347
Chapter 8 Updating Data in Down-Level Clients ........................ 391
Chapter 9 Updating Remote Cached Data ........................................ .475
Chapter 10 Components for Updating Data ........................................ 527
Chapter 11 Rich Client Update Applications ................................. 583
Chapter 12 Reconciling Update Errors .............................................. 647
Chapter 13 Updating Data from Remote .NET Applications ....... 715
Index ...................................................................................................................... 765
iii
Contents
About the Authors ............................................................................................ xiii
Introduction ........................................................................................................ xv
Chapter 1 The Distributed Application ................................... 1
What Are Distributed Data Applications? ............................................... 2
Our Definition .................................................................................................... 2
Why Do You Need to Distribute? ....................................................................... 3
How Can You Do ((Distributed}) on the Internet? .................................. 5
Internet Protocols ............................................................................................... 5
Internet Clients ................................................................................................... 6
The Elements of a Distributed Application ........................................... 8
Client Devices and Client Applications .......................................................... 10
Server-Side Data Stores .................................................................................... 12
Processing and Presenting Information ......................................................... 14
Data Access Techniques Overview .............................................................. .20
About "Relational" Data Access ....................................................................... 21
The ADO. NET Data Access Classes ................................................................. 22
Understanding System.Xml .............................................................................. 32
Representing Data and Information ............................................................... 33
The System.XrnI Classes ................................................................................... 37
Data Access and the n-Tier Model ............................................................ .41
What Is the Data Being Used For? ................................................................... 41
Some n -Tier Data Access Scenarios ............................................................... .44
Summary ................................................................................................................... 51
Chapter 2 Components and Data Access .................................... 53
Different Types of ((Component}) ................................................................. 54
.NET Components ............................................................................................ 54
COM and COM+ Components ........................................................................ 58
User Controls .................................................................................................... 59
Include Files ...................................................................................................... 63
Server Controls ................................................................................................. 64
Accessing and Exposing Data ........................................................................ 64
Delivering Data to Rich Clients ....................................................................... 64
Managing Data for Down-Level Clients ......................................................... 65
Displaying XML Data ....................................................................................... 65
v
Contents
Working with the DataSet Object ............................................................... 66
The Structure of the DataSet Object ............................................................... 66
When Should You Use a DataSet? .................................................................... 69
Relational Data Access Component Examples ........................................ 70
Setting Up the Examples .................................................................................. 70
Accessing and Returning Relational Data ...................................................... 72
Summary ................................................................................................................ 107
Chapter 3 Accessing XML Documents .......................................... 109
Introducing the XML Data Access Component Examples .................. 109
Accessing and Returning Relational Data .......................................... 110
Using the SupplierListXml Data Access Component .................................. 111
Returning an XmITextReader Reference ....................................................... 112
Returning an XmlValidatingReader Reference ............................................ 11 8
Returning a DataSet Object ........................................................................... 123
Returning a Custom Array Reference ........................................................... 126
Returning an ArrayList Reference ................................................................. 130
Returning an XML String ............................................................................... 133
Returning an XmIDocument Object ............................................................. 135
Returning anXPathDocument Object .......................................................... 137
Summary ................................................................................................................ 141
Chapter 4 The Application Plumbing ....................................... 143
Overview of Client-Side Techniques ..................................................... 144
Available Client-Side Programming Techniques ......................................... 144
Choosing Client Support ............................................................................... 145
Remoting Data to the Client .................................................................... 151
Remoting Relational Data to the Client ........................................................ 151
Remoting XML Data to the Client ................................................................. 154
Running the .NET Framework on the Client ................................................ 157
Using ASP. NET Sessions ............................................................................... 172
Sessions Configuration in ASP. NET .............................................................. 172
Checking for Session Support ....................................................................... 175
Munging URLs for Session Support .............................................................. 176
Client Detection Example ........................................................................... 177
Overview of the Process ................................................................................. 177
Detecting the Client Type .............................................................................. 178
The default.aspxPage .................................................................................... 182
Detection Errors and Unsupported Clients ................................................. 184
Checking for Client- Side Scripting Support ................................................. 1 84
vi
Contents
Redirecting the Client If Scripting Is Enabled .............................................. 185
The Device-Specific Home Pages .................................................................. 186
Viewing the Results ........................................................................................ 191
Summary ................................................................................................................ 196
Chapter 5 Working with Down-Level Clients ..................... 199
A Mul tiple-Client Order List Application ........................................ 200
The User Interface ..........................................................................................2 01
Detecting the Client Type ......................................................................... 202
The Data Access Tier .................................................................................... 206
Maximizing Efficiency Through Data Caching ............................................ 206
The Order List Application: The HTML Version ............................... 207
The Outline Process .......................................................................................2 08
Searching for Customers ................................................................................2 09
Displaying a List of Customers ...................................................................... 211
Displaying a List of Orders ............................................................................. 220
Displaying the Order Details ......................................................................... 229
The Order List Application: The Mobile Version ........................... 235
The Outline Process ....................................................................................... 236
Fetching Data from the Server ...................................................................... 238
The Mobile Page Content .............................................................................. 242
Summary ................................................................................................................ 259
Chapter 6 Working with Rich Clients ..................................... 261
Working wi th XML ............................................................................................ 262
Why XSL and XSLT? ........................................................................................ 262
Exposing and Delivering niL ....................................................................... 262
Using XML in Internet Explorer 5 and Higher ................................. 264
Building the Middle Tier ................................................................................ 264
Selecting a Customer ..................................................................................... 271
Selecting an Order .......................................................................................... 285
Viewing Order Details .................................................................................... 293
Extracting the Order Details .......................................................................... 294
Using Web Services in Internet Explorer 5 and Higher .............. 297
Looking at the Customer Data Web Service ................................................. 298
Testing a Web Service ..................................................................................... 300
Building the Middle Tier ................................................................................ 302
The Internet Explorer 5 WebService Behavior ............................................. 305
vii
Contents
Building the Hypertext Application Example ................................... 310
Running the Example Hypertext Application .............................................. 311
Loading the XML Data ................................................................................... 313
Building the Middle Tier ................................................................................ 314
The HTA Page Content ................................................................................... 316
Selecting an Order .......................................................................................... 323
Working with Delimited Text Data ......................................................... 324
Why Use Delimited Text Data? ...................................................................... 324
Remember the TDC? ...................................................................................... 324
Building the Middle Tier ................................................................................ 325
Selecting a Customer ..................................................................................... 331
Selecting and Viewing an Order .................................................................... 338
Client -Side Data Binding with XML Anyone? .............................................. 345
Summary ................................................................................................................ 345
Chapter 7 Remoting to . NET Clients ....................................... 347
Remoting Refresher ......................................................................................... 348
Remoting Objects .............................................................................................. 348
The Remotable Object Class .......................................................................... 349
The Remote Server ......................................................................................... 349
The Remote Client .......................................................................................... 352
Deploying the Objects .................................................................................... 356
The Windows Application .............................................................................. 356
The Design Choices ........................................................................................ 359
Remoting Data to Windows Applications ..................................................... 359
Building the Windows Application ............................................................... 360
Creating the Web Services .............................................................................. 364
Incremental Downloads ................................................................................... 368
Creating a Downloadable Form .................................................................... 368
Loading the Form Dynamically ..................................................................... 369
The Download Cache ..................................................................................... 372
Strong Named Assemblies and the Download Cache ................................. 374
Deployment ........................................................................................................... 374
Security ............................................................................................................... 375
Security Policy ................................................................................................ 377
Modifying the Security Policy ........................................................................ 379
Checking Permissions .................................................................................... 386
Dynamic Applications .................................................................................... .388
Summary ................................................................................................................ 389
viii
Contents
Chapter 8 Updating Data in Down-Level Clients ...........
391
Updating Data Stores: An Overview ........................................................ 392
Making the Process As Efficient As Possible ................................................. 392
Measuring the Results and Providing Feedback .......................................... 394
Controlling Access to Protect the Data ......................................................... 394
Controlling Concurrent Data Updates ......................................................... 395
Data Update Techniques in .NET ............................................................... 397
Using Transactions While Updating Data .................................................... .404
Managing Concurrency While Updating ...................................................... 408
Data Update Example for HTML 3.2 Clients ........................................ .412
An Overview of the Application .................................................................... 413
Displaying and Editing Orders ...................................................................... 418
Displaying and Editing the Order Contents ................................................ .452
Data Update Example for Mobile Devices .............................................. 467
The Application Design ................................................................................. 467
Viewing the Application ................................................................................. 469
Summary ................................................................................................................. 473
Chapter 9 Updating Remote Cached Data .............................. .475
Reviewing the Architecture ........................................................................ 476
Caching Updates on the Client ..................................................................... 477
Getting Updates Back to the Server .............................................................. 478
Loading a DataSet .......................................................................................... 480
Executing the Update Process .................................................................. .498
Providing Feedback from the Update Process ............................................ .499
The Update Process in Detail ........................................................................ 503
A Data Update Process Example ................................................................... 505
Summary .................................................................................................................5 25
Chapter 10 Components for Updating Data ............................. 527
The UpdateDataSet Component ...................................................................... 528
Enabling Tracing from Within a Component ............................................... 528
Writing to the Trace Object ............................................................................ 530
The Common Methods in the Component .................................................. 532
Managing IDENTITY Columns for Inserted Rows ....................................... 533
The UpdateAlIOrderDetails Method ............................................................. 549
Creating the Parameterized Command Objects .......................................... 563
ix
Contents
Using the UpdateDataSet Component ....................................................... 570
Filling the DataSet .......................................................................................... 572
Editing Some RowValues ............................................................................... 573
Changing the Underlying Database Values Concurrently .......................... 575
Performing the Update .................................................................................. 577
Displaying the Update Errors ........................................................................ 578
Deleting the New Rows You Added ............................................................... 580
Viewing the Trace Information ...................................................................... 581
Summary ................................................................................................................ 582
Chapter 11 Rich Client Update Applications ..................... 583
How This Chapter Is Organized ................................................................ 584
An Overview of the Application .............................................................. 585
The Process in Outline ................................................................................... 586
Checking for Concurrency Errors ................................................................. 587
The Middle Tier ASP. NET Page .................................................................. 587
Getting the Data from the Data Access Tier ................................................. 588
Exposing the Data to the Client ..................................................................... 588
Loading the Di ffgrams on the Client ................................................... 589
Loading the Orders Data ................................................................................ 590
Loading the Shippers Data ............................................................................ 591
Loading the Products Data ............................................................................ 593
Editing a .NET DataSet Diffgram ........................................................... 594
Viewing the Updated Diffgram ..................................................................... 595
The Updated Diffgram Format ...................................................................... 598
The edit-orders. aspx Page Code and HTML .......................................... 603
Creating the List of Orders ............................................................................. 603
Posting the Updated Diffgram to the Server ................................................ 605
Displaying Details of the Selected Order ...................................................... 609
Creating the List of Order Lines .................................................................... 616
Creating the Update Line and Delete Line Buttons ..................................... 618
It's Time to Talk Dirty ...................................................................................... 618
Updating the Orders Diffgram ...................................................................... 620
Summary ................................................................................................................ 644
Chapter 12 Reconciling Update Errors ..................................... 647
Reconciling Update Errors in Overview .............................................. 648
A Summary of the Process ............................................................................. 648
The Error Reporting and Reconciliation Process ......................................... 649
Displaying Trace Information ....................................................................... 654
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