Add cache metadata automatically

Needs review.

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Wow, that's good to know. I suggest adding a protected method, `prepareValue(),` to the base plugin class, which will return an initiated cacheable string object instance.

I suggest adding a protected method, prepareValue(), to the base plugin class, which will return an initiated cacheable string object instance.

Hi @voleger. I don't quite understand this suggestion. What would be the difference between prepareValue() and getValue()?

I suggest adding an API to prepare the value (which includes a cache metadata wrapper) for plugin implementations. I just suggested the name of the method which provides that, so naming is open for discussion.

Do you mean something like this?

abstract class GlobalVariable {
  protected $value;

  abstract function prepareValue();

  function getValue() {
    if (empty($this->value)) {
      $this->prepareValue();
    }
    return $this->value;
  }

}

class MyVariable extends GlobalVariable {

  function prepareValue() {
    $this->value = new StringVariableValue('foo');
    $this->value->addCacheableDependency($bar);
  }

}