ICfnConditionExpression

class aws_cdk.core.ICfnConditionExpression(*args, **kwargs)

Bases: aws_cdk.core.IResolvable, typing_extensions.Protocol

Represents a CloudFormation element that can be used within a Condition.

You can use intrinsic functions, such as Fn.conditionIf, Fn.conditionEquals, and Fn.conditionNot, to conditionally create stack resources. These conditions are evaluated based on input parameters that you declare when you create or update a stack. After you define all your conditions, you can associate them with resources or resource properties in the Resources and Outputs sections of a template.

You define all conditions in the Conditions section of a template except for Fn.conditionIf conditions. You can use the Fn.conditionIf condition in the metadata attribute, update policy attribute, and property values in the Resources section and Outputs sections of a template.

You might use conditions when you want to reuse a template that can create resources in different contexts, such as a test environment versus a production environment. In your template, you can add an EnvironmentType input parameter, which accepts either prod or test as inputs. For the production environment, you might include Amazon EC2 instances with certain capabilities; however, for the test environment, you want to use less capabilities to save costs. With conditions, you can define which resources are created and how they’re configured for each environment type.

You can use toString when you wish to embed a condition expression in a property value that accepts a string. For example:

# Example automatically generated. See https://github.com/aws/jsii/issues/826
sqs.Queue(self, "MyQueue",
    queue_name=Fn.condition_if("Condition", "Hello", "World").to_string()
)
__init__(*args, **kwargs)

Methods

resolve(context)

Produce the Token’s value at resolution time.

Parameters

context (IResolveContext) –

Return type

Any

to_string()

Return a string representation of this resolvable object.

Returns a reversible string representation.

Return type

str

Attributes

creation_stack

The creation stack of this resolvable which will be appended to errors thrown during resolution.

If this returns an empty array the stack will not be attached.

Return type

List[str]