Adobe ColdFusion 8

cferror

Description

Displays a custom HTML page when an error occurs. This lets you maintain a consistent look and feel among an application's functional and error pages.

Category

Exception handling tags, Extensibility tags, Application framework tags

Syntax

<cferror 
    template = "template path"
    type = "exception|validation|request"
    exception = "exception type"
    mailTo = "e-mail address">

Note: You can specify this tag's attributes in an attributeCollection attribute whose value is a structure. Specify the structure name in the attributeCollection attribute and use the tag's attribute names as structure keys.

See also

cfrethrow, cfthrow, cftry, "Handling Errors" 41 in the ColdFusion Developer's Guide.

History

ColdFusion MX: Deprecated the monitor option of the exception attribute. It might not work, and might cause an error, in later releases.

Attributes

Attribute

Req/Opt

Default

Description

template

Required

 

Relative path to the custom error page. (A ColdFusion page was formerly called a template.)

type

Required

 

Type of error that the custom error page handles. The type also determines how ColdFusion handles the error page. For more information, see "Specifying a custom error page" 49 in the ColdFusion Developer's Guide.

  • exception: an exception of the type specified by the exception attribute.
  • validation: errors recognized by server-side type validation.
  • request: any encountered error.

exception

Optional

any

Type of exception that the tag handles:

  • application: application exceptions.
  • database: database exceptions.
  • template: ColdFusion page exceptions.
  • security: security exceptions.
  • object: object exceptions.
  • missingInclude: missing include file exceptions.
  • expression: expression exceptions.
  • lock: lock exceptions.
  • custom_type: developer-defined exceptions, defined in the cfthrow tag.
  • any: all exception types.

For more information on exception types, see cftry.

mailTo

Optional

 

An e-mail address. This attribute is available on the error page as the variable error.mailto. ColdFusion does not automatically send anything to this address.

Usage

Use this tag to provide custom error messages for pages in an application. This lets you maintain a consistent look and feel within the application, even when errors occur.

You generally embed this tag in your Application CFC or Application.cfm file to specify error-handling responsibilities for an entire application. You must put it in one of these files if you specify type="validation"; ColdFusion ignores it on any other page.

The cftry and cfcatch tags provide a more interactive way to handle ColdFusion errors within a ColdFusion page than the cferror tag, but the cferror tag is a good safeguard against general errors.

To ensure that error pages display successfully, avoid using the cfencode utility to encode pages that include the cferror tag.

Page types

The following table describes the types of errors you can specify and code you can use on the pages that handle these error type:

Page type

Description

Use

Exception

Dynamically invoked by the CFML language processor when it detects an unhandled exception condition.

Uses the full range of CFML tags. Error variables must be in cfoutput tags.

Can handle specific exception types or display general information for exceptions.

Request

Includes the error variables described in the Error variables section.

Cannot include CFML tags, but you can display values of the error variables by enclosing them in number signs (#), as in #error.MailTo#.

Use as a backup error handler to other error handling methods, including exception type.

Validation

Handles data input validation errors that occur when submitting a form that uses hidden form-field validation or onSubmit validation.

Cannot include CFML tags, but you can display values of the error variables by enclosing them in number signs (#), as in #Error.InvalidFields#.

You must specify the validation error handler in the Application.cfc or Application.cfm file.

Handles hidden form-field or onSubmit format validation errors only.

Error variables

The exception-handling page specified in the cferror tag template attribute contains one or more error variables. ColdFusion substitutes the value of the error variable when an error displays.

The following table lists error variables:

Page type

Error variable

Description

Validation only

error.validationHeader

Validation message header text.

error.invalidFields

Unordered list of validation errors.

error.validationFooter

Validation message footer text.

Request and Exception

error.diagnostics

Detailed error diagnostics from ColdFusion MX.

error.mailTo

E-mail address (same as value in cferror.MailTo).

error.dateTime

Date and time when error occurred.

error.browser

Browser that was running when error occurred.

error.remoteAddress

IP address of remote client.

error.HTTPReferer

Page from which client accessed link to page where error occurred.

error.template

Page executing when error occurred.

error.generatedContent

The content generated by the page up to the point where the error occurred.

error.queryString

URL query string of client's request.

Exception only

error.message

Error message associated with the exception.

error.rootCause

The root cause of the exception. This structure contains the information that is returned by a cfcatch tag. For example, for a database exception, the SQL statement that caused the error is in the error.RootCause.Sql variable. For Java exceptions, this variable contains the Java servlet exception reported by the JVM as the cause of the "root cause" of the exception.

error.tagContext

Array of structures containing information for each tag in the tag stack. The tag stack consists of each tag that is currently open.

error.type

Exception type.

Note: If type = "exception", you can substitute the prefix cferror for Error; for example, cferror.diagnostics, cferror.mailTo, or cferror.dateTime.

Example

<h3>cferror Example</h3>

<!--- Example of cferror call within a page.
         NOTE: If you use cferror type="VALIDATION" you MUST put it in
         Application.cfc or Application.cfm --->
<cferror type = "REQUEST"
template = "request_err.cfm"
mailTo = "admin@mywebsite.com">
<!--- This query calls a non-existent datasource, triggering an error to be handled. --->
<cfquery name="testQuery" datasource="doesNotExist">
select * from nothing
</cfquery>

<!--- Example of the page (request_err.cfm) to handle this error. --->
<html>
<head>
<title>We're sorry -- An Error Occurred</title>
</head> 
<body>
<h2>We're sorry -- An Error Occurred</h2>
<p>
If you continue to have this problem, please contact #error.mailTo#
with the following information:</p>
<p>
<ul>
<li><b>Your Location:</b> #error.remoteAddress#
<li><b>Your Browser:</b> #error.browser#
<li><b>Date and Time the Error Occurred:</b> #error.dateTime#
<li><b>Page You Came From:</b> #error.HTTPReferer#
<li><b>Message Content</b>:
<p>#error.diagnostics#</p>
</ul>