get<O> method

O? get<O>(String key, [ O instantiator()?, bool cacheValidator(Object o)? ])

Returns an object for key.

Uses instantiator (or pre-defined) to instantiate.

Uses cacheValidator (or pre-defined) to validade already cached instance.

Implementation

O? get<O>(String key,
    [O Function()? instantiator, bool Function(Object o)? cacheValidator]) {
  var o = _cacheInstances[key];

  if (o != null) {
    cacheValidator ??= _cacheValidators[key];

    if (cacheValidator != null) {
      var ok = cacheValidator(o);
      if (ok) {
        return o;
      } else {
        _cacheInstances.remove(key);
      }
    } else {
      return o;
    }
  }

  instantiator ??= _cacheInstantiators[key] as O Function()?;
  if (instantiator == null) return null;

  if (maxInstances != null && maxInstances! > 0) {
    var needToRemove = _cacheInstances.length - (maxInstances! - 1);
    disposeInstances(needToRemove);
  }

  o = instantiator();
  _cacheInstances[key] = o;

  return o;
}