MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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Using ColdFusion components 227
To invoke a method of a component instance using the cfinvoke tag:
1
Create a file named tellTime2.cfc with the following code:
<cfcomponent>
<cffunction name="getLocalTime" access="remote">
<cfreturn TimeFormat(now())>
</cffunction>
<cffunction name="getUTCTime" access="remote">
<cfscript>
serverTime=now();
utcTime=GetTimeZoneInfo();
utcStruct=structNew();
utcStruct.Hour=DatePart("h", serverTime);
utcStruct.Minute=DatePart("n", serverTime);
utcStruct.Hour=utcStruct.Hour + utcTime.utcHourOffSet;
utcStruct.Minute=utcStruct. utcTime.utcMinuteOffSet;
if (utcStruct.Minute LT 10)
utcStruct.Minute = "0" & utcStruct.Minute;
</cfscript>
<cfreturn utcStruct.Hour & ":" & utcStruct.Minute>
</cffunction>
</cfcomponent>
The example defines two component methods:
getLocalTime
and
getUTCTime
.
2
Create a new ColdFusion page, with the following code and save it in the same directory as the
tellTime component:
<!--- Create the component Instance --->
<cfobject component="tellTime2" name="tellTimeComp">
<!--- Invoke the methods --->
<cfinvoke component="#tellTimeComp#" method="getLocalTime"
returnvariable="localTime" >
<cfinvoke component="#tellTimeComp#" method="getUTCTime"
returnvariable="UTCTime" >
<!--- Display the results --->
<h3>Time Display Page</h3>
<cfoutput>
Server's Local Time: #localTime#<br>
Calculated UTC Time: #UTCTime#
</cfoutput>
This example modifies and expands the example from the “Invoking component methods
transiently using the cfinvoke tag” section. It uses the
cfobject
tag to create an instance of the
tellTime component and the
cfinvoke
tag to invoke the instance’s
getLocalTime
and
getUTCTime
methods. Unlike the CFC example in “Invoking component methods transiently
using the cfinvoke tag” , these methods return a value to the caller, and do not display the results
directly; instead, the calling page displays the returned results.
This example is more modular than the previous example because the CFC contains the
functional logic and returns a result to the calling page, and the calling page displays the results.
This structure separates the logic from the display functions, which usually results in more
reusable code.