Post-Initialization in extbase domain model

Question

In one of my extbase models, I want to initialize some properties derived from the properties that are saved in the database. The computation of these virtual properties is time consuming, so I'd like to cache them. Thus my program flow should look somehow like this:

1. Load the domain object as usual from the database
2. Check if the virtual property is available in cache. If so, fetch it from there, otherwise compute and cache it.

I first thought the method "initializeObject" is what I need, but it is not: It is called before any property is initialized from the database. So I came up with two other ways:

1. I can call an initialization-method manually from the repository after fetching the object, but that seems weird and would break if someone adds another find* method to the general repository.
2. Another idea is to add a boolean "virtualPropertiesInitialized" to the model, query it whenever one of the virtual properties is accessed and initialize the virtual properties if needed. Also seems weird, but would not break if someone adds another "find"-method to the generic repository.

My question is:

Is there a default/best-practice how to do what I want to do?

Answer 1

If reading the final value from disk or database is less computationally intensive, then store the value using the TYPO3 caching framework or by your own caching method of a static class and restore it in the getter of the virtual property. Doing it in the getter method public mixed getYourPropery() will give you the feature that the value is only get from the cache when you call it.

On the second call, just return the value you stored previously:

private $myValue = NULL;

public function getMyValue() {
    if($this->myValue != NULL) return $this->myValue;

    $this->myValue = "test";
    return $this->myValue;
}