Fn::Transform
The intrinsic function Fn::Transform
specifies a macro to perform custom
processing on part of a stack template. Macros enable you to perform custom processing on
templates, from simple actions like find-and-replace operations to extensive transformations
of entire templates. For more information, see Perform custom processing on templates with template macros.
You can also use Fn::Transform
to call the AWS::Include transform
transform, which is a macro hosted by AWS CloudFormation.
Declaration
JSON
Syntax for the full function name:
{ "Fn::Transform": { "Name": "
macro name
", "Parameters": { "Key
": "value
" } } }
Syntax for the short form:
{ "Transform": { "Name": "
macro name
", "Parameters": { "Key
": "value
" } } }
YAML
Syntax for the full function name:
Fn::Transform: Name :
macro name
Parameters :Key
:value
Syntax for the short form:
!Transform Name:
macro name
Parameters:Key
:value
Parameters
- Name
-
The name of the macro you want to perform the processing.
- Parameters
-
The list parameters, specified as key-value pairs, to pass to the macro.
Return value
The processed template snippet to be included in the processed stack template.
Examples
The following example calls the AWS::Include
transform, specifying that the
location to retrieve a template snippet from is passed in the InputValue
parameter.
JSON
{ "Fn::Transform": { "Name": "AWS::Include", "Parameters": { "Location": { "Ref": "InputValue" } } } }
YAML
'Fn::Transform': Name: 'AWS::Include' Parameters: Location: !Ref InputValue
Supported functions
None.
CloudFormation passes any intrinsic function calls included in Fn::Transform
to
the specified macro as literal strings. For more information, see CloudFormation macro function
interface.