Dagger & rxjava & retrofit

Dagger & RxJava & Retrofit

Ted

what is Dagger

Dagger is a Dependency Injector

example1

public class School { public Teacher teacher = new Teacher();}

Cons?

● school 裡會有很多teacher，但是如果沒有setter 代表school必須跟teacher綁定

● how to test?

example2

public class School { public Teacher teacher ;

public void setTeacher(Teacher t){teacher = t;

}}

Pros

● now we can set whoever we want.● and easy to test

TestSample

s = new Schoole();s.setTeacher(new MockTeacher());assert.equals(s.getTeacherName(),”balabala”);

so...how to use dagger

● source (Module)● target (class)

Source (Module)

create a @Moduletell the module you are going to @Inject to which class@Provides a type to that class

Target(class)

@Inject the Modules to classauto @Inject to field or get type by code

example1

demo and explain

https://github.com/nightbear1009/Dagger_StepBySteprepository = feature/simpleDagger

example2

demo and explain

https://github.com/nightbear1009/Dagger_StepBySteprepository = feature/plusIfNecessary

what’s the meaning of plus?

AppGraph

NetworkModules

AccountModules

what’s the meaning of plus?

AppGraph

NetworkModules

AccountModules

LoginGraph

LoginHelperModules

App + Login GraphUserLogin

what’s the meaning of plus?

AppGraph

NetworkModules

AccountModules

UserLogout

what about test

override

example3

https://github.com/nightbear1009/Dagger_StepBySteprepository = feature/testTeacher

Rxjava

Funtional Programing

forEach rx.Observable.from("1","2","3").forEach(new Action1<String>() {

@Override

public void call(String s) {

Log.d("Ted","s "+s);

}

});

s 1

s 2

s 3

map rx.Observable.from("1","2","3").map(new Func1<String, Boolean>() {

@Override

public Boolean call(String s) {

return s.equals("1");

}

}).subscribe(new Action1<Object>() {

@Override

public void call(Object o) {

Log.d("Ted","o "+o);

}

});

o true

o false

o false

flapMap rx.Observable.from("1","2","3").flatMap(new Func1<String, rx.Observable<?>>() {

@Override

public rx.Observable<?> call(String s) {

Log.d("Ted","num "+s);

return rx.Observable.from(s);

}

}).subscribe(new Action1<Object>() {

@Override

public void call(Object o) {

}

});

num 1

num 2

num 3

filterrx.Observable.from("1","2","3").filter(new Func1<String, Boolean>() {

@Override

public Boolean call(String s) {

return s.equals("1");

}

}).subscribe(new Action1<String>() {

@Override

public void call(String s) {

Log.d("Ted","s "+s);

}

});

s 1

toSortedListrx.Observable.from("1","3","2").toSortedList(new Func2<String, String, Integer>() {

@Override

public Integer call(String s, String s2) {

return Integer.valueOf(s2) - Integer.valueOf(s);

}

}).subscribe(new Action1<List<String>>() {

@Override

public void call(List<String> strings) {

for(String s :strings){

Log.d("Ted","s "+s);

}

}

});

s 3

s 2

s 1

groupby

false integer 1 false integer 3

true integer 2 true integer 2 false integer 3

false integer 5 true integer 6 false integer 7

true integer 8 false integer 9

Observable.just vs Observable.from

一次丟全部資料和一次丟一筆資料的差別?

without publish + connect D s url1 D s url2 D s url3 D s2 url1 D s2 url2 D s2 url3

publish + connect

D s url1 D s2 url1 D s url2 D s2 url2 D s url3 D s2 url3

refcount

還沒時間看XD

Pros & Cons

Proslogic will be clear

Conshigh leaning curvelots of callback(with retrolamda maybe better)

Ingram 說

http://ingramchen.io/blog/2014/10/retromlambda.html

華生大大 說

https://twitter.com/jakewharton/status/385898996884971520

過了幾個月後 華生大大又說..

華生大大 again

都是別人說，現在換我說XD

rxjava的確算是較大型的lib，learning curve比較高，有很多東西需要花時間學習＆了解.but如果我們只是用來處理 api + data handle 而不用來處理複雜的邏輯 or data combining... (https://github.com/nightbear1009/RxAndroid-Login-Sample )，我相信會是個不錯的選擇

Retrofit

three steps1. create interface2. create api3. handleData

retrofit

1. build in gson2. no need to implement parcelable3. easy to test

test

test more with gradle + dagger

前情提要：

randy: 有沒有可能寫出 XXXListView.get(url) ; 然後就可以畫出layout的辦法?https://github.com/nightbear1009/SmallDaggerRetrofitRxjavaSample

當然，目前的版本還有很多高耦合的問題必須解決，ex : adapter 但或許是個將view 封裝的一個方向？

so… what can we do with these lib

Demo Time again

Conclusion

● use Retrofit to handle Network api● use dagger to injection every retrofit’s

adapter(so we can mock the api data)

● use rxjava to handle every event including api call back(so our logic will be clearly)