Building ColdFusion components
235
Using the GetMetaData function
The CFML
GetMetaData
function returns a structure containing all the metadata of a CFC
instance. This structure contains substantially more data about the CFC than
cfdump
shows, and
includes the following information:
•
All attributes to the component tag, including any metadata-only attributes, plus the
component path.
•
An array of structures containing full information on each method (function) in the
component. This information includes all attributes, including metadata-only function and
parameter attributes.
•
Within each function structure, a Parameters element containing an array of parameters
specified by
cfargument
tags. Information on each parameter includes any metadata-only
attributes.
•
Information about any properties that are specified using the
cfproperty
tag
For information on how to specify CFC metadata, including how to use component tags and how
to specify metadata-only attributes, see
“Documenting CFCs” on page 240
.
Building ColdFusion components
You use the
cfcomponent
and
cffunction
tags to create ColdFusion components. By itself, the
cfcomponent
tag does not provide functionality. Rather, the
cfcomponent
tag provides an
envelope that describes the functionality that you build in CFML and enclose in
cffunction
tags.
The following example creates a component with two methods:
<cfcomponent>
<cffunction name="getEmp">
<cfquery name="empQuery" datasource="ExampleApps" dbtype="ODBC" >
SELECT FIRSTNAME, LASTNAME, EMAIL
FROM
tblEmployees
</cfquery>
<cfreturn empQuery>
</cffunction>
<cffunction name="getDept">
<cfquery name="deptQuery" datasource="ExampleApps" dbtype="ODBC" >
SELECT
*
FROM
tblDepartments
</cfquery>
<cfreturn deptQuery>
</cffunction>
</cfcomponent>
In the example, two
cffunction
tags define two component methods,
getEmp
and
getDept
.
When invoked, the component methods query the ExampleApps database. The
cfreturn
tag
returns the query results to the client.
The following sections discuss how you define components and their methods.
Содержание COLDFUSION MX 61-DEVELOPING 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...
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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...
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Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...