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Chapter 6: Extending ColdFusion Pages with CFML Scripting
About CFScript
CFScript is a language within a language. It is a scripting language that is similar to JavaScript but
is simpler to use. Also, unlike JavaScript, CFScript only runs on the ColdFusion server; it does
not run on the client system. CFScript code can use all the ColdFusion functions and expressions,
and has access to all ColdFusion variables that are available in the script’s scope.
CFScript provides a compact and efficient way to write ColdFusion logic. Typical uses of
CFScript include the following:
•
Simplifying and speeding variable setting
•
Building compact JavaScript-like flow control structures
•
Creating user-defined functions
Because you use functions and expressions directly in CFScript, you do not have to surround each
assignment or function in a
cfset
tag. Also, CFScript assignments are often faster than
cfset
tags.
CFScript provides a set of decision and flow-control structures that are more familiar than
ColdFusion tags to most programmers.
In addition to variable setting, other operations tend to be slightly faster in CFScript than in tags.
ColdFusion 5 and later releases let you use CFScript to create user-defined functions, or UDFs
(also known as custom functions). You call UDFs in the same manner that you call standard
ColdFusion functions. UDFs are to ColdFusion built-in functions what custom tags are to
ColdFusion built-in tags. Typical uses of UDFs include data manipulation and mathematical
calculation routines.
You cannot include ColdFusion tags in CFScript. However, a number of functions and CFScript
statements are equivalent to commonly used tags. For more information, see
“CFScript
functional equivalents to ColdFusion tags” on page 131
.
Comparing tags and CFScript
The following examples show how you can use CFML tags and CFScript to do the same thing.
Each example takes data submitted from a form and puts it in a structure; if the form does not
have a last name and department field, it displays a message.
Using CFML tags
<cfif IsDefined("Form.submit")>
<cfif (Form.lastname NEQ "") AND (Form.department NEQ "")>
<cfset employee=structnew()>
<cfset employee.firstname=Form.firstname>
<cfset employee.lastname=Form.lastname>
<cfset employee.email=Form.email>
<cfset employee.phone=Form.phone>
<cfset employee.department=Form.department>
<cfoutput>
Adding #Form.firstname# #Form.lastname#<br>
</cfoutput>
<cfelse>
<cfoutput>
You must enter a Last Name and Department.<br>
</cfoutput>
</cfif>
</cfif>
Содержание ColdFusion MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...