MACROMEDIA COLFUSION MX 7-CFML, Reference

Page: 567 / 1108

DE 567
The following example shows how you can use the
DE
function and number signs together, and
shows how the function works with an
IIF
function:
<cfoutput>
<cfset var1=Blue>
<cfset var2=Green>
<cfset myresult=IIf( 1 eq 2, DE(#Var1#), DE(#Var2#))>
The expression is #myresult#
</cfoutput>
ColdFusion processes this code as follows:
1.
ColdFusion sets the variables
var1
and
var2
to be the strings Blue and Green.
2.
In the fourth line, ColdFusion evaluates the variables surrounded by number signs first,
replacing them with the strings Blue and Green, the values of the variables.
3.
The
IIF
function evaluates the test expression, determines that it is False, and then evaluates
the third parameter.
4.
The third parameter is a
DE
function, which takes the string Green and surrounds it in quotation
marks
5.
The
IIF
function returns the string "Green", including the quotation marks.
6.
The
cfset
tag gets the expression result="Green", and sets the value of the
myresult
variable
to the string Green.
7.
ColdFusion evaluates
#myresult#
in the output text, replaces the variable with its value, the
string Green, and displays the result.
Example
<!--- This example shows the use of DE and Evaluate --->
<h3>DE Example</h3>
<cfif IsDefined("FORM.myExpression")>
<cftry>
<!--- Show the expression and the results of evaluating it --->
<cfoutput>
<h3>Evaluate the Expression #FORM.MyExpression#</h3>
</cfoutput>
The code:<br>
#Evaluate(FORM.myExpression)#
<br><br>
The result:<br>
<cfoutput>
#Evaluate(FORM.myExpression)#
</cfoutput>
<h3>Use DE to prevent the Evaluate function from evaluating</h3>
The code:<br>
#Evaluate(DE(FORM.MyExpression))#<br><br>
The result:<br>
<cfoutput>
#Evaluate(DE(FORM.MyExpression))#
</cfoutput>
<!--- Error handling code for bad expressions and any other error.--->
<cfcatch type = "Any">