CFML Reference
ColdFusion Functions

DE

Description

Postpones evaluation of a string as an expression, when it is passed as a parameter to the IIf or Evaluate functions. Escapes any double quotation marks in the parameter and wraps the result in double quotation marks.

This function is especially useful with the IIf function, to prevent the function from evaluating a string that is to be output.

This applies to expressions that are not surrounded by pound signs. (If pound signs surround any part of an expression, a ColdFusion function evaluates that part first, regardless of whether the DE function is present.)

Return value

Parameter, surrounded by double quotation marks, with any inner double quotation marks escaped.

Category

Dynamic evaluation functions

Syntax

DE(string) 

See also

Evaluate, IIf

Parameters

Parameter	Description
string	String to evaluate, after delay

Usage

Consider this example:

<condition> <true expression> <false expression>
iif( 1 eq 2, DE('#Var1#'), DE('#Var2#'))

ColdFusion evaluates whatever is surrounded by pounds in the expression before executing it. So, although this expression is never true (because Var1 does not exist), the expression fails with an 'Error Resolving Parameter' error, because ColdFusion evaluates #Var1#' and #Var2#' before executing either expression.

This example returns 'Var2':

iif( 1 eq 2, DE('Var1'), DE('Var2')) 

The following example uses IIF to alternate table-row background colors, white and gray. It uses the DE function to prevent ColdFusion from evaluating the color strings.

<cfoutput>

<table border="1" cellpadding="3">
<cfloop index="i" from="1" to="10">
  <tr bgcolor="#IIF( i mod 2 eq 0, DE("white"), DE("gray") )#">
    <td>
      hello #i#
    </td>
  </tr>
</cfloop>
</table>
</cfoutput>

For more information and code examples, see Developing ColdFusion MX Applications with CFML.

Example

<!--- This example shows the use of DE and Evaluate --->
<h3>DE Example</h3>
<cfif IsDefined("FORM.myExpression")>
<h3>The Expression Result</h3>
<cftry>
<!--- Evaluate the expression --->
<cfset myExpression = Evaluate(FORM.myExpression)>
<!--- Use DE to output the value of the variable, unevaluated --->
<cfoutput>
<I>The value of the expression #Evaluate(DE(FORM.MyExpression))#
is #MyExpression#.</I>
</cfoutput>
<!--- specify the type of error for which we are searching --->
<cfcatch type = "Any">
<!--- the message to display --->
  <h3>Sorry, there's been an <B>Error</B>.
  Try a simple expression, such as "2+2".</h3>
<cfoutput>
<!--- and the diagnostic message from ColdFusion Server --->
  <p>#cfcatch.message#
</cfoutput>
</cfcatch>
</cftry>
</cfif>

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