MACROMEDIA COLDFUSION 5 - INSTALING AND CONFIGURING SERVER Manual de Instruções descarregar pdf (Página 126)

116 Lesson 4 Validating Data to Enforce Business Rules

Reviewing the code

The following table describes the code used to verify whether a file exists:

Exercise: use FileExists function to verify the existence of photo file name

In this exercise, you will use the Cold Fusion

FileExists function to ensure that the

photo file name entered in the Trip Edit page exists in the location specified.

To verify that the photo file name exists:

1 Open the tripeditaction.cfm in the my_app directory in your editor.

2 In the tripeditaction.cfm page, do the following:

a Add logic to check that the user entered a valid photo file name by copying the

code from the photofilecheck.txt file in the solutions directory pasting it

immediately following the first <cfset isOk = "Yes"> statement.

b Verify that code you copied in step a is pointing to the correct photolocation

path. The path is specified in the <cfset PhotoLocation = "C:..."> tag.

For example, depending on your web server configuration, the photolocation

path might be:

• For MS Windows systems:

<cfset PhotoLocation

"C:\cfusionmx\wwwroot\CFDOCS\getting_started\Photos\">

<cfset PhotoLocation =

"C:\Inetpub\wwwroot\CFDOCS\getting_started\Photos\">

• For Linux or Solaris systems:

<cfset PhotoLocation =

"/opt/coldfusionmx/wwwroot/cfdocs/getting_started/photos/">

<cfset PhotoLocation =

"/<webserverdocroot>/cfdocs/getting_started/photos/">

Code Explanation

The cfif tag checks to see if the form variable

testFileName has been entered.

<cfset fileLocation = fileLocation &

form.testFileName>

The ColdFusion & operator in the cfset tag

combines the original value for fileLocation

from the first source line

("c:\inetpub\wwwroot\images\") with the value

of the testFileName form variable.

FileExists checks to see if the file indicated by

the fileLocation variable exists at the specified

disk location.

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MACROMEDIA COLDFUSION 5 - INSTALING AND CONFIGURING SERVER Manual de Instruções Página 126