315
CHAPTER 15
Using Persistent Data and Locking
ColdFusion MX provides several variable scopes in which data persists past the life of a single
request. These are the Client, Application, Session, and Server scopes. These scopes let you save
data over time and share data between pages and even applications. (This chapter refers to these
scopes as
persistent
scopes.) In particular, you can use the Client and Session scopes to maintain
information about a user across multiple requests.
ColdFusion MX lets you lock access to sections of code to ensure that ColdFusion does not
attempt to run the code, or access the data that it uses, simultaneously or in an unpredictable
order. This locking feature is important for ensuring the consistency of all shared data, including
data in external sources in addition to data in persistent scopes.
This chapter describes how to use persistent scopes to develop an application and how to use
locking to ensure data consistency.
Contents
About persistent scope variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Managing the client state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
Configuring and using client variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Configuring and using session variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Configuring and using application variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Using server variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Locking code with cflock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Examples of cflock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Summary of Contents for ColdFusion MX
Page 1: ...Developing ColdFusion MX Applications...
Page 22: ...22 Contents...
Page 38: ......
Page 52: ...52 Chapter 2 Elements of CFML...
Page 162: ......
Page 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Page 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Page 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Page 266: ......
Page 314: ...314 Chapter 14 Handling Errors...
Page 344: ...344 Chapter 15 Using Persistent Data and Locking...
Page 349: ...About user security 349...
Page 357: ...Security scenarios 357...
Page 370: ...370 Chapter 16 Securing Applications...
Page 388: ...388 Chapter 17 Developing Globalized Applications...
Page 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Page 410: ......
Page 426: ...426 Chapter 19 Introduction to Databases and SQL...
Page 476: ...476 Chapter 22 Using Query of Queries...
Page 534: ...534 Chapter 24 Building a Search Interface...
Page 556: ...556 Chapter 25 Using Verity Search Expressions...
Page 558: ......
Page 582: ...582 Chapter 26 Retrieving and Formatting Data...
Page 668: ......
Page 734: ...734 Chapter 32 Using Web Services...
Page 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Page 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Page 788: ......