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Add support for OptionalBinder to link to normal bindings of that typ…
…e if
neither setDefault nor setBinding are called. From the javadoc, example:
* <pre><code>
* public class FrameworkModule extends AbstractModule {
* protected void configure() {
* OptionalBinder.newOptionalBinder(binder(), Renamer.class);
* }
* }</code></pre>
*
* <p>With this module, an {@link Optional}{@code <Renamer>} can now be
* injected. With no other bindings, the optional will be absent.
* Users can specify bindings in one of two ways:
*
* <p>Option 1:
* <pre><code>
* public class UserRenamerModule extends AbstractModule {
* protected void configure() {
* bind(Renamer.class).to(ReplacingRenamer.class);
* }
* }</code></pre>
*
* <p>or Option 2:
* <pre><code>
* public class UserRenamerModule extends AbstractModule {
* protected void configure() {
* OptionalBinder.newOptionalBinder(binder(), Renamer.class)
* .setBinding().to(ReplacingRenamer.class);
* }
* }</code></pre>
* With both options, the {@code Optional<Renamer>} will be present and supply the
* ReplacingRenamer.
-------------
Created by MOE: http://code.google.com/p/moe-java
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -76,9 +76,11 @@ | |
| * setBinding to a Provider that returns null will not cause OptionalBinder | ||
| * to fall back to the setDefault binding. | ||
| * | ||
| * <p>If neither setDefault nor setBinding are called, the optionals will be | ||
| * absent. Otherwise, the optionals will return present if they are bound | ||
| * to a non-null value. | ||
| * <p>If neither setDefault nor setBinding are called, it will try to link to a | ||
| * user-supplied binding of the same type. If no binding exists, the optionals | ||
| * will be absent. Otherwise, if a user-supplied binding of that type exists, | ||
| * or if setBinding or setDefault are called, the optionals will return present | ||
| * if they are bound to a non-null value. | ||
| * | ||
| * <p>Values are resolved at injection time. If a value is bound to a | ||
| * provider, that provider's get method will be called each time the optional | ||
|
|
@@ -96,18 +98,27 @@ | |
| * }</code></pre> | ||
| * | ||
| * <p>With this module, an {@link Optional}{@code <Renamer>} can now be | ||
| * injected. With no other bindings, the optional will be absent. However, | ||
| * once a user adds a binding: | ||
| * injected. With no other bindings, the optional will be absent. | ||
| * Users can specify bindings in one of two ways: | ||
| * | ||
| * <p>Option 1: | ||
| * <pre><code> | ||
| * public class UserRenamerModule extends AbstractModule { | ||
| * protected void configure() { | ||
| * bind(Renamer.class).to(ReplacingRenamer.class); | ||
| * } | ||
| * }</code></pre> | ||
| * | ||
| * <p>or Option 2: | ||
| * <pre><code> | ||
| * public class UserRenamerModule extends AbstractModule { | ||
| * protected void configure() { | ||
| * OptionalBinder.newOptionalBinder(binder(), Renamer.class) | ||
| * .setBinding().to(ReplacingRenamer.class); | ||
| * } | ||
| * }</code></pre> | ||
| * .. then the {@code Optional<Renamer>} will be present and supply the | ||
| * ReplacingRenamer. | ||
| * With both options, the {@code Optional<Renamer>} will be present and supply the | ||
| * ReplacingRenamer. | ||
| * | ||
| * <p>Default values can be supplied using: | ||
| * <pre><code> | ||
|
|
@@ -127,6 +138,24 @@ | |
| * } | ||
| * }</code></pre> | ||
| * ... which will override the default value. | ||
| * | ||
| * <p>If one module uses setDefault the only way to override the default is to use setBinding. | ||
| * It is an error for a user to specify the binding without using OptionalBinder if | ||
| * setDefault or setBinding are called. For example, | ||
| * <pre><code> | ||
| * public class FrameworkModule extends AbstractModule { | ||
| * protected void configure() { | ||
| * OptionalBinder.newOptionalBinder(binder(), Key.get(String.class, LookupUrl.class)) | ||
| * .setDefault().to(DEFAULT_LOOKUP_URL); | ||
| * } | ||
| * } | ||
| * public class UserLookupModule extends AbstractModule { | ||
| * protected void configure() { | ||
| * bind(Key.get(String.class, LookupUrl.class)).to(CUSTOM_LOOKUP_URL); | ||
| * } | ||
| * }</code></pre> | ||
| * ... would generate an error, because both the framework and the user are trying to bind | ||
| * {@code @LookupUrl String}. | ||
| * | ||
| * @author [email protected] (Sam Berlin) | ||
| */ | ||
|
|
@@ -257,7 +286,7 @@ private RealOptionalBinder(Binder binder, Key<T> typeKey) { | |
| */ | ||
| private void addDirectTypeBinding(Binder binder) { | ||
| binder.bind(typeKey).toProvider(new RealOptionalBinderProviderWithDependencies<T>(typeKey) { | ||
| public T get() { | ||
| @Override public T get() { | ||
| Optional<Provider<T>> optional = optionalProviderT.get(); | ||
| if (optional.isPresent()) { | ||
| return optional.get().get(); | ||
|
|
@@ -268,7 +297,7 @@ public T get() { | |
| return null; | ||
| } | ||
|
|
||
| public Set<Dependency<?>> getDependencies() { | ||
| @Override public Set<Dependency<?>> getDependencies() { | ||
| return dependencies; | ||
| } | ||
| }); | ||
|
|
@@ -286,7 +315,7 @@ public Set<Dependency<?>> getDependencies() { | |
| return binder.bind(actualKey); | ||
| } | ||
|
|
||
| public void configure(Binder binder) { | ||
| @Override public void configure(Binder binder) { | ||
| checkConfiguration(!isInitialized(), "OptionalBinder was already initialized"); | ||
|
|
||
| binder.bind(optionalProviderKey).toProvider( | ||
|
|
@@ -297,6 +326,7 @@ public void configure(Binder binder) { | |
| RealOptionalBinder.this.binder = null; | ||
| actualBinding = injector.getExistingBinding(actualKey); | ||
| defaultBinding = injector.getExistingBinding(defaultKey); | ||
| Binding<T> userBinding = injector.getExistingBinding(typeKey); | ||
| Binding<T> binding = null; | ||
| if (actualBinding != null) { | ||
| // TODO(sameb): Consider exposing an option that will allow | ||
|
|
@@ -306,6 +336,12 @@ public void configure(Binder binder) { | |
| binding = actualBinding; | ||
| } else if (defaultBinding != null) { | ||
| binding = defaultBinding; | ||
| } else if (userBinding != null) { | ||
| // If neither the actual or default is set, then we fallback | ||
| // to the value bound to the type itself and consider that the | ||
| // "actual binding" for the SPI. | ||
| binding = userBinding; | ||
| actualBinding = userBinding; | ||
| } | ||
|
|
||
| if (binding != null) { | ||
|
|
@@ -321,11 +357,11 @@ public void configure(Binder binder) { | |
| } | ||
| } | ||
|
|
||
| public Optional<Provider<T>> get() { | ||
| @Override public Optional<Provider<T>> get() { | ||
| return optional; | ||
| } | ||
|
|
||
| public Set<Dependency<?>> getDependencies() { | ||
| @Override public Set<Dependency<?>> getDependencies() { | ||
| return providerDependencies; | ||
| } | ||
| }); | ||
|
|
@@ -348,7 +384,7 @@ private class RealOptionalKeyProvider | |
| super(typeKey); | ||
| } | ||
|
|
||
| public Optional<T> get() { | ||
| @Override public Optional<T> get() { | ||
| Optional<Provider<T>> optional = optionalProviderT.get(); | ||
| if (optional.isPresent()) { | ||
| return Optional.fromNullable(optional.get().get()); | ||
|
|
@@ -357,11 +393,12 @@ public Optional<T> get() { | |
| } | ||
| } | ||
|
|
||
| public Set<Dependency<?>> getDependencies() { | ||
| @Override public Set<Dependency<?>> getDependencies() { | ||
| return dependencies; | ||
| } | ||
|
|
||
| @SuppressWarnings("unchecked") | ||
| @Override | ||
| public <B, R> R acceptExtensionVisitor(BindingTargetVisitor<B, R> visitor, | ||
| ProviderInstanceBinding<? extends B> binding) { | ||
| if (visitor instanceof MultibindingsTargetVisitor) { | ||
|
|
@@ -371,11 +408,11 @@ public <B, R> R acceptExtensionVisitor(BindingTargetVisitor<B, R> visitor, | |
| } | ||
| } | ||
|
|
||
| public Key<Optional<T>> getKey() { | ||
| @Override public Key<Optional<T>> getKey() { | ||
| return optionalKey; | ||
| } | ||
|
|
||
| public Binding<?> getActualBinding() { | ||
| @Override public Binding<?> getActualBinding() { | ||
| if (isInitialized()) { | ||
| return actualBinding; | ||
| } else { | ||
|
|
@@ -384,7 +421,7 @@ public Binding<?> getActualBinding() { | |
| } | ||
| } | ||
|
|
||
| public Binding<?> getDefaultBinding() { | ||
| @Override public Binding<?> getDefaultBinding() { | ||
| if (isInitialized()) { | ||
| return defaultBinding; | ||
| } else { | ||
|
|
@@ -393,7 +430,7 @@ public Binding<?> getDefaultBinding() { | |
| } | ||
| } | ||
|
|
||
| public boolean containsElement(Element element) { | ||
| @Override public boolean containsElement(Element element) { | ||
| Key<?> elementKey; | ||
| if (element instanceof Binding) { | ||
| elementKey = ((Binding<?>) element).getKey(); | ||
|
|
@@ -445,14 +482,12 @@ public RealOptionalBinderProviderWithDependencies(Object equality) { | |
| this.equality = equality; | ||
| } | ||
|
|
||
| @Override | ||
| public boolean equals(Object obj) { | ||
| @Override public boolean equals(Object obj) { | ||
| return this.getClass() == obj.getClass() | ||
| && equality.equals(((RealOptionalBinderProviderWithDependencies<?>) obj).equality); | ||
| } | ||
|
|
||
| @Override | ||
| public int hashCode() { | ||
| @Override public int hashCode() { | ||
| return equality.hashCode(); | ||
| } | ||
| } | ||
|
|
||
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