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POTATO

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Why Potato?SQL is so 80’s.

Wake me up before you:

• Map objects to tables

• Write serializers

• Write queries

• Implement content provider schemes

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Potato v. Android

Application needs:

• Fetch data from web service

• Persistence

• UI that relies on objects

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Android API

• SQLite - SQLiteOpenHelper - DB Schema - Cursor - ContentValues

• ContentProvider

• Loader

• ListView

• Observer

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Potato

• Storage - Storage.List - Subscriptions

• Poll

• PollListView

public class UserStorage extends Storage<User> {.... @Override public String id(User user) { return user.getId(); }...}

Storage• Non-volatile storage via json serialization

• Based on generic lrucache<string,t> (least recently used) - size device dependent

• Push(t object)

• Delete(string id)

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Storage.List• A section of storage

• Obtain list from storage

• Implements java.Util.List<t>

Storage<User>.List friends = UserStorage.obtainList(Const.LIST_FRIENDS);

Storage<User>.List followers = UserStorage.obtainList(Const.LIST_FOLLOWERS);

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Storage.Subscription List•Subscribe for a single object or list

•React to different actions (PUSH, DELETE … )

UserStorage.getInstance().obtainList(Const.LIST_FOLLOWERS).subscribe(new Storage.Subscription() {@Override public void onUpdate(Action action) { mFollowerLabel.post(new Runnable() { @Override public void run() { ... } }); }});

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UserStorage.getInstance().subscribe(mUserId, new Subscription() { @Override public void onUpdate(Action action) { mUserLabel.post(new Runnable() { @Override public void run() { ... } }); }});

Storage.Subscription Object

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Poll

• Associated to a storage.List

• Fetch new data

• Fetch old data

• States OK / NO_CONTENT / ERROR

What can it do for you?

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Poll

• setStorage(Storage<T>.List storage)

• ArrayList<User> newItems()

• ArrayList<User> oldItems()

• int appendNewItems(ArrayList<T> newItems, Listener listener, boolean cleanUp)

• int appendOldItems(ArrayList<T> newItems, Listener listener)

What you have to do...

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PollListView• Extends com.handmark.pulltorefresh.PullToRefreshListView

• Bound a poll with a ListView - new data on pull to refresh - old data on scroll

• Subscribes for poll’s Storage.List

• Attached to Activity/Fragment lifecycle - save/load/update

• Different adapters related to poll state

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Potato structure

object object

object object

object object

object object

object object

object object

object object

object object

object object

object

object

object object

Storage

Storage.List

Storage.List

Sto

rage.L

ist

Sto

rage.L

ist

object object

Less used

Most used

Subscribe to events comingfrom lists or individual items

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Performance diagram

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Interaction diagram

API Poll Storage.List PollListView

(UI)

AnimatedPollAdapter

(UI)

2. API call

3. add Upfront

4. notify DataWillUpdate

5. notify DataSetChangedWithAction

notify DataSetChanged

Event is publishedover subscription

model

1. update

return data

{

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Extra potatoPotato can do even more

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Example

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Pota TO DO:

• Object revisioning ( createdAt / updatedAt )

• More work on UI

• Java code generation with universal Boll (to any API)

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End Fork the potato

Łukasz Wisniewski

Tobias Heine

lukasz@eyeem.com

tobi@eyeem.com

@vishna

https://github.com/eyeem/PotatoLibrary

@tobias_heine

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