1 /**
2 * This file Copyright (c) 2017-2018 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.ui.framework.ioc;
35
36 import java.util.Optional;
37
38 import com.google.inject.Key;
39 import com.google.inject.Provider;
40 import com.google.inject.ProvisionException;
41 import com.google.inject.Scopes;
42
43 /**
44 * Simple Guice {@link com.google.inject.Scope scope} implementation bound to
45 * a {@link BeanStore}.
46 * <p>
47 * This is a foundation class for the Magnolia UI scopes;
48 * it is capable of caching the instances created by Guice
49 * in the corresponding bean store. The only thing a concrete
50 * scope implementation has to specify is how to resolve the
51 * bean store ({@link #getStore()} method).
52 * </p>
53 */
54 abstract class SessionStoreScope implements UiScope {
55
56 protected abstract UiContextReference getCurrentContextKey();
57
58 protected BeanStore getStore() {
59 return SessionStore.access().getBeanStore(getCurrentContextKey());
60 }
61
62 @Override
63 public <T> Provider<T> scope(Key<T> key, Provider<T> creator) {
64 return () -> getInstanceFromBeanStore(key, creator);
65 }
66
67 private <T> T getInstanceFromBeanStore(Key<T> key, Provider<T> creator) {
68 final BeanStore beanStore = getStore();
69 if (beanStore == null) {
70 throw new ProvisionException(String.format("No bean store registered for provided key [%s]...", key));
71 }
72 return Optional.ofNullable(beanStore.get(key)).orElseGet(() -> {
73 final T unscopedValue = creator.get();
74 if (!Scopes.isCircularProxy(unscopedValue)) {
75 beanStore.put(key, unscopedValue);
76 }
77 return unscopedValue;
78 });
79 }
80 }