%BHHFS 0QUJPOBMCJOEJOHT

ࣗݾ঺հ ๺ଜྋ גࣜձࣾ͸ͯͳ )BUFOBGVOOFMCJU 5XJUUFS!FYQFSPQFSP

w %SPJEP,BJHJʹొஃ͠·͢ w λΠτϧେن໛ΞϓϦͷϦϊϕʔγϣϯ

0QUJPOBMΛఆٛ͠ ޙͰ ղܾͯ͠΋Β͏ !#JOET0QUJPOBM0G

!#JOET0QUJPOBM0G w 0QUJPOBMCJOEJOHΛ࣮ݱ͢Δػೳ w 0QUJPOBM5Λฦ͢ఆٛΛ༻ҙ͢Δ w ಉ͡ίϯϙʔωϯτ͔ɺαϒίϯϙʔωϯτͰ ஋ΛຬͨͤΔ w %BHHFSd

&OUSZ public class Entry {
 public final String title;
 public Entry(String title) {
 this.title = title;
 }
 }

.PEVMF BCTUSBDU @Module
 public abstract class MainModule {
 @BindsOptionalOf
 public abstract Entry optionalEntryProvider();
 }

$PNQPOFOU @Component(modules = {MainModule.class})
 public interface MainComponent {
 Optional entry();
 }

.BJO"DUJWJUZ public class MainActivity extends AppCompatActivity {
 …
 MainComponent mainComponent = DaggerMainComponent.create();
 
 Optional entry = mainComponent.entry();
 Log.e(“entry”, entry.or(new Entry(“default")).title); …
 } w EFGBVMUͱදࣔ͞ΕΔ

.PEVMF @Module
 public class EntryModule {
 @Provides
 public Entry provideEntry() {
 return new Entry(“entry");
 }
 }

$PNQPOFOU @Component(modules = {MainModule.class, EntryModule.class})
 public interface MainComponent {
 Optional entry();
 }

.BJO"DUJWJUZ public class MainActivity extends AppCompatActivity {
 …
 Optional entry = mainComponent.entry();
 Log.e(“entry”, entry.or(new Entry(“default")).title); …
 } w FOUSZͱදࣔ͞ΕΔ

$PNQPOFOU ͝ͱʹ ஋ΛมԽͤ͞Δ

&OUSZΛఏڙ͢Δ 4VC$PNQPOFOU &OUSZΛఏڙ͠ͳ͍ 4VC$PNQPOFOU 0QUJPOBMΛ༻ҙ͢Δ $PNQPOFOU 0QUJPOBMΛίϯετϥΫλ Ͱड͚औΔΫϥε "DUJWJUZ 0QUJPOBM5 03

0QUJPOBMΛίϯετϥΫλ Ͱड͚औΔΫϥε public class EntryManager {
 private final Entry mEntry;
 @Inject
 public EntryManager(Optional entryOptional) {
 mEntry = entryOptional.or(new Entry("default"));
 }
 
 public String getTitle() {
 return mEntry.title;
 }
 }

&OUSZΛఏڙ͠ͳ͍ $PNQPOFOU @Subcomponent
 public interface EmptyComponent {
 void inject(MainActivity activity);
 @Subcomponent.Builder
 interface Builder {
 EmptyComponent build();
 }
 }

&OUSZΛఏڙ͢Δ $PNQPOFOU @Subcomponent(modules = SavedEntryModule.class)
 public interface SavedEntryComponent {
 void inject(MainActivity activity);
 @Subcomponent.Builder
 interface Builder {
 SavedEntryComponent build();
 }
 }

&OUSZΛఏڙ͢Δ $PNQPOFOU @Module
 public class SavedEntryModule {
 @Provides Entry provideEntry() {
 return new Entry("saved");
 }
 }

"DUJWJUZ public class MainActivity extends AppCompatActivity {
 @Inject EntryManager mEntryManager;
 …
 DaggerMainComponent
 .create()
 .emptyComponent()
 .build()
 .inject(this);
 Log.e("title", mEntryManager.getTitle()); // default
 
 DaggerMainComponent
 .create()
 .savedEntryComponent()
 .build()
 .inject(this);
 Log.e("title", mEntryManager.getTitle()); // saved
 }

·ͱΊ w 0QUJPOBMͷ஋ΛޙͰղܾͰ͖Δ w 4VC$PNQPOFOUຖʹࠩҟΛग़ͤΔ w !*OKFDU͕ॻ͔ΕͨϑΟʔϧυɺίϯετϥΫ λͰ΋ͦͷ0QUJPOBMΛड͚औΕΔ w ໪࿦$PNQPOFOU͔ΒήολͰऔΔ͜ͱ΋Ͱ ͖Δ

ࢀߟ w IUUQTHPPHMFHJUIVCJPEBHHFSVTFST HVJEF

͋Γ͕ͱ͏͍͟͝·ͨ͠