public ComponentImpl(ApformComponent apform) throws InvalidConfiguration {
    if (apform == null) {
      throw new InvalidConfiguration("Null apform instance while creating component");
    }

    this.apform = apform;
    this.declaration = apform.getDeclaration();
  }
  /**
   * To be called once the Apam entity is fully initialized.
   *
   * <p>Computes all its attributes, including inheritance. Checks if initial properties are
   * consistent with the declarations.
   *
   * <p>NOTE this method is also called when the owner changes, to force recalculation of
   * substitutions that depend on the current owner.
   */
  private void initializeProperties(Map<String, String> initialProperties) {

    Component group = getGroup();

    /*
     * Currently the instance declaration may include invalid properties.
     *
     * For declared instances this should not happen as the declaration is validated at build-time. For dynamically
     * created instances (using the APAM API or the apform API directly) this should be validated by this method.
     *
     * However, there are many properties added by the iPOJO apform layer that need to be ignored, so we simply
     * silently ignore all invalid properties.
     *
     * TODO We should be able to distinguish properties specified by the user that must be validated, from properties
     * used internally by the iPOJO apform.
     */
    Set<String> invalidDeclaredProperties = new HashSet<String>();
    for (String property : getDeclaration().getProperties().keySet()) {

      boolean isDefined =
          getDeclaration().isDefined(property)
              || (group != null && group.getPropertyDefinition(property) != null);

      if (!isDefined) {
        invalidDeclaredProperties.add(property);
      }

      if (group != null && group.getProperty(property) != null) {
        invalidDeclaredProperties.add(property);
      }
    }

    getDeclaration().getProperties().keySet().removeAll(invalidDeclaredProperties);

    /*
     * Merge initial and declared properties.
     *
     */
    Map<String, String> fullInitialProperties =
        new HashMap<String, String>(getDeclaration().getProperties());
    if (initialProperties != null) {
      fullInitialProperties.putAll(initialProperties);
      fullInitialProperties.remove("instance.name");
    }

    /*
     * NOTE  In the case of change owner, the initial properties include inherited values from the group,
     * we ignore them to avoid false error messages, they will be added later by the normal inheritance
     * mechanism
     *
     * TODO Distinguish the case of change owner from a real initialization
     */
    if (initialProperties != null && group != null) {
      for (Map.Entry<String, String> initialProperty : initialProperties.entrySet()) {
        if (group.getProperty(initialProperty.getKey()) != null
            && group.getProperty(initialProperty.getKey()).equals(initialProperty.getValue())) {
          fullInitialProperties.remove(initialProperty.getKey());
        }
      }
    }

    // start cleaning the properties (normally empty)
    clear();

    /*
     *  First add the valid attributes.
     */
    for (Map.Entry<String, String> initialProperty : fullInitialProperties.entrySet()) {

      PropertyDefinition def = validDef(initialProperty.getKey(), true);
      if (def != null) {
        Object val =
            Attribute.checkAttrType(
                initialProperty.getKey(), initialProperty.getValue(), def.getType());
        if (val != null) {
          put(initialProperty.getKey(), val);
        }
      }
    }

    /*
     *  then add those coming from its group, avoiding overloads.
     */
    if (group != null) {
      for (String attr : group.getAllProperties().keySet()) {
        if (get(attr) == null) {
          put(attr, ((ComponentImpl) group).get(attr));
        }
      }
    }

    /*
     * Add the default values specified in the group for properties not explicitly specified
     */
    if (group != null) {
      for (PropertyDefinition definition : group.getDeclaration().getPropertyDefinitions()) {
        if (definition.hasDefaultValue()
            && get(definition.getName()) == null
            && definition.getInjected() != InjectedPropertyPolicy.INTERNAL) {
          Object val =
              Attribute.checkAttrType(
                  definition.getName(), definition.getDefaultValue(), definition.getType());
          if (val != null) {
            put(definition.getName(), val);
          }
        }
      }
    }

    /*
     * Set the attribute for the final attributes
     */
    put(CST.SHARED, Boolean.toString(isShared()));
    put(CST.SINGLETON, Boolean.toString(isSingleton()));
    put(CST.INSTANTIABLE, Boolean.toString(isInstantiable()));

    /*
     * Finally add the specific attributes.
     * Should be the only place where instanceof is used.
     */
    put(CST.NAME, apform.getDeclaration().getName());
    if (this instanceof Specification) {
      put(CST.SPECNAME, apform.getDeclaration().getName());
    } else if (this instanceof Implementation) {
      put(CST.IMPLNAME, apform.getDeclaration().getName());
      if (this instanceof CompositeType) {
        put(CST.APAM_COMPOSITETYPE, CST.V_TRUE);
      }
    } else if (this instanceof Instance) {
      put(CST.INSTNAME, apform.getDeclaration().getName());
      if (this instanceof Composite) {

        Composite composite = (Composite) this;
        put(CST.APAM_COMPOSITE, CST.V_TRUE);
        if (composite.getMainInst() != null) {
          put(CST.APAM_MAIN_INSTANCE, composite.getMainInst().getName());
        }
      }
    }

    /*
     *  and propagate, to the platform and to members, in case the spec has been created after the implem
     */
    for (Map.Entry<String, Object> entry : this.entrySet()) {
      for (Component member : getMembers()) {
        ((ComponentImpl) member).propagate(entry.getKey(), entry.getValue());
      }
    }
  }