Slide presented in Roppongi aar #3

1. In 2016, how do you implement
"Web API client Activity"?
Tsuyoshi Yoshioka (@tsuyogoro)
Mercari, Inc.

2. About me
Tsuyoshi Yoshioka (@tsuyogoro)
Android engineer
Mercari, Inc

3. How do you implement this app?
Using a web API - http://zipcloud.ibsnet.co.jp/doc/api

4. Today’s focus on
How to support “orientation change” ?

5. Base of my idea
Activity
(Portrait)
Activity
(Landscape)
Data
Model
API task
Web API
(Search address)
share share
“Wait…” dialog
1. How to share “Data model” ?
2. How to share “API task” ?
3. How to show ProgressDialog in correct period ?

6. We have 3 weapons
● Databinding
● RxJava
● Lifecycle of Activity & Fragment

7. 1.Sharing model with databinding
public class ZipSearchActivityModel implements Serializable {
private static final long serialVersionUID = 123L;
/**
* ユーザの入力した郵便番号
*
*/
public ObservableField<String> zipCode
= new ObservableField<>();
/**
* 検索した結果の住所
* (場合によってはエラー文言を表示するのに使う)
*
*/
public ObservableField<String> address
= new ObservableField<>();
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@={model.zipCode}"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:layout_marginBottom="16dp"
android:text="@{model.address}"/>
☆ Two-way binding
https://halfthought.wordpress.com/2016/03/23/2-way-data-binding-on-android/

8. 1.Sharing model with databinding
Can implement model sharing,
Quite simple & safely
public class ZipSearchActivityModel implements Serializable {
private static final long serialVersionUID = 123L;
/**
* ユーザの入力した郵便番号
*
*/
public ObservableField<String> zipCode
= new ObservableField<>();
/**
* 検索した結果の住所
* (場合によってはエラー文言を表示するのに使う)
*
*/
public ObservableField<String> address
= new ObservableField<>();
} Serializable
Serializable
Can use android studio plug-in
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putSerializable(BUNDLE_KEY_MODEL, model);
}

9. 2. Task sharing with RxJava
ZipSearchTask.buildRequest(model.zipCode.get())
.flatMap(ZipSearchTask::submitRequest)
.flatMap(ZipSearchTask::parseResponse)
.delay(5, TimeUnit.SECONDS)
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(mySubscriber);
Task
Listener

10. Base of my idea
Activity
(Portrait)
Activity
(Landscape)
Data
Model
Observable
Web API
(Search address)
share shareSubscriber

11. 2. Task sharing with RxJava
public class RxZipSearchActivity extends AppCompatActivity {
private MySubscriber mySubscriber;
@Override
protected void onCreate(Bundle savedInstanceState) {
...
mySubscriber = (MySubscriber) getLastCustomNonConfigurationInstance();
if (mySubscriber != null) {
mySubscriber.activeActivity = this;
}
...
@Override
public Object onRetainCustomNonConfigurationInstance() {
return mySubscriber;
}
Can implement task sharing,
Quite simple & safely

12. 3. Progress dialog
private void showProgressDialog() {
if (getSupportFragmentManager().findFragmentByTag(TAG_PROGRESS_DIALOG) == null) {
new ProgressDialogFragment().show(getSupportFragmentManager(), TAG_PROGRESS_DIALOG);
}
}
public static class ProgressDialogFragment extends AppCompatDialogFragment {
@Override
protected void onResume() {
super.onResume();
// まだ通信の途中だったらdialogを出す
if (mySubscriber != null && !mySubscriber.isUnsubscribed()) {
showProgressDialog();
}
● Avoid multiple dialog showing
● Subscriber can be a clue if to show progress dialog

13. Summary
Introduced my idea to implement simple WebAPI client app
We have efficient way in 2016 (databinding, RxJava)
Let’s discuss how you design / implement such application now?
(Source code intoduced in my presentation)
https://github.com/tsuyoyo/roppongi-aar3-address-search-app

14. 2. RxJava Can implement task sharing, Quite simple & safely
public class RxZipSearchActivity extends AppCompatActivity {
private static class MySubscriber extends Subscriber<List<String>> {
private RxZipSearchActivity activeActivity;
@Override
public void onCompleted() { Log.d("TestTestTest", "onCompleted"); }
@Override
public void onError(Throwable e) { notifyResult(e.getMessage()); }
@Override
public void onNext(List<String> result) {
activeActivity.notifyResult(result);
onCompleted();