In the AWS CDK, it's straight forward to create a Pinpoint Service. But how do you get the Project ID (also referred to as the Pinpoint App ID or Application ID) for use in subsequent CDK code.
Create a Pinpoint project:
const pinpointProject = new pinpoint.CfnApp(this, 'PinpointNotificationProject', {
name: 'myProject',
});
In the AWS CloudFormation docs it says: "When you pass the logical ID of this resource to the intrinsic Ref function, Ref returns the unique identifier (ApplicationId) for the Amazon Pinpoint application."
However, the following CDK code returns the project name not the id. The value of logicalId = myProject.
cdk.Fn.ref(pinpointProject.logicalId); // This returns 'myProject'
pinpointProject.ref; // This also returns 'myProject'
The problem you are running into is that pinpoint is not a finished module. You can see this that all the functions within are prefixed with Cfn - cloudformation. This means that they are barebones and not tied into all the interface hooks that the rest of CDK is making use of to toss things around.
First, the logical ID is NOT the project name. the Logical Id is part of the Cloudformation Template that is generated for any resource Cloudformation is going to stand up. It links the given resource to the stack, so that any changes under the same logical id will be applied to the same stood up resource. It is only referenced internally to the cloudformation stack and never known outside. CDK uses the LogicalID to generate the name of the resource if you do not specify one.
Second, Taking a look at the documentation shows that CfnApp has the following property: attrArn. Meaning in your code, you would reference this by pinpointProject.attrArn - the arn of a pinpoint resource is something like: arn:aws:mobiletargeting:region:accountId:apps/projectId. with, as you guessed it, the projectId as the last value. you can split the string and get that value out, or use the arn manipulation methods provided as part of the core module to extract what you need.
Finally, even though the Pinpoint module is pretty much just barebones, it may still be possible to pass the variable storing your Pinpoint Construct Object to whatever other resource requires it. I say may because, as mentioned, most of the Cfn prefixed functions do not have the proper hooks to do this well - but some do, and Ive never worked with Pinpoint directly.
I recommend spending some time to understand how the CDK Documentation is laid out. Its bare bones in places, but once you understand how they structured it, these kinds of questions are readily answered within.