skygear-oct-update.slide

Skygear.io at Oursky
Oct Progress Update
9 Oct 2015

Roy Yuen
Oursky
royuen@oursky.com

* Offical naming

We have finally decided to call "ourd" service as Skygear.io!

All SDK class prefix renaming and document site will be updated soon.

* Projects adopted

Now we have 2 projects using Skygear as backend at the moment:

- uFO (iOS) - Your one stop restauant menu
- Taylors (Web) - A web portal to manage projects in a writing company

And more client projects would use skygear as backend soon:

- Village (iOS)
- Fesh (iOS, TBC)

*  Doc site (DRAFT) is ready!

If you are interested, please visit:

- Guideline / Tutorial: http://docs.pandadb.com/tutorial/toc/
- iOS SDK class reference: http://docs.pandadb.com/ios/

The guideline site has all basic introduction to Skygear, setup guideline, and also each SDK's development guidelines / examples.

They are currently in basic draft and we will continue to improve them.

* Plugin System

- Database Extension Point
- Handler Extension Point
- Lambda Function
- Authentication Provider
- Scheduled Tasks

Plugin example:

    import pyourd

    @pyourd.op("chima:echo")
    def echo():
        return {"message": "Hello World"}

* Plugin System - Database Extension Point

- `before_save` — executes decorated function before a record save operation occurs
- `before_delete` — executes decorated function before a record delete operation occurs
- `after_save` — executes decorated function before a record save operation occurs
- `after_delete` — executes decorated function before a record save operation occurs

    @pyourd.before_save("note", async=False)
    def update_word_count(record, original_record, db):
        word_list = record["content"].split(" ")
        record["word_count"] = len(word_list)
        return record

* Plugin System - Handler Extension Point

- Create a custom handler for your application to call

    @pyourd.handler("chima:echo", auth_required=True)
    def meow(payload, io):
        io.write(payload)
        return

In your iOS application, you need to subclass the ODOperation class, and implement prepareForRequest, handleResponse and handleRequestError function.

    - (void)prepareForRequest {
        NSDictionary *payload = @{@"timezone": self.timezone};
        self.request = [[ODRequest alloc] initWithAction:@"chima:echo" payload:payload];
        self.request.accessToken = self.container.currentAccessToken;
    }

To call the handler in plugin, your should add the operation object to [ODContainer addOperation:]


* Plugin System - Lambda Function

- Using handler may be tricky because you need to define everything yourself. As a convinent approach you could use Lambda instead

    @pyourd.op("hello:world")
    def say(name="world!"):
        return {"message": "Hello " + name}

And from your application, you could call above endpoint by:

    [container callLambda:@"hello:world" 
                arguments:@[@"dingdong"] 
        completionHandler:^(NSDictionary *response, NSError *error) {

        if (error) {
            NSLog(@"error calling hello:world: %@", error);
            return;
        }

        NSLog(@"Received response = %@", response);
    }];

* Plugin System - Authentication Provider

Allow you to extend skygear's authentication functionality to other social services such as facebook / github

    import pyourd
    import pyourd.providers
    import facebook

    @pyourd.provides("auth", "com.facebook")
    class FacebookProvider(pyourd.providers.BaseAuthProvider):
        def login(self, auth_data):
            graph = facebook.GraphAPI(access_token=auth_data['access_token'])
            auth_data.update(graph.get_object(id='me'))
            return {"principal_id": auth_data['id'], "auth_data": auth_data}

* Plugin System - Authentication Provider

And in iOS app, to login with custom auth plugin

    - (void)loginWithData:(NSDictionary *)dict
    {
        ODUserLoginOperation *op = [ODUserLoginOperation operationWithAuthenticationProvider:@"com.example" data:dict]
        op.loginCompletionBlock = ^(ODUserRecordID *userID, ODAccessToken *accessToken, NSError *error) {
            NSLog(@"User ID: %@", userID)
        };
        [[ODContainer defaultContainer] addOperation:op];
    }


* Plugin System - Scheduled Tasks

It's easy to create a periodic job in ourd as a plugin

    @pyourd.every("@every 1m")
    def watch(io):
        open('/tmp/messages.txt', 'a').write('Hello World!\n')

In this case the watch function would be called every minute.


* JS SDK

Besides iOS SDK, we have also created the JS SDK. It's still in early development. It covers:

- CRUD records
- Users authentication

* Pubsub support

Ourd now supports pubsub interface. You can use it to create real time update experience in Skygear applications.

For example in iOS, you can subscribe to a channel with this:

    ODContainer *container = [ODContainer defaultContainer];
    [container.pubsubClient subscribeTo:@"hello" handler:^(NSDictionary *info) {
        NSString *name = info[@"name"];
        NSLog(@"%@ says hello", name);
    }];

And in plugin, you can publish a message in the channel

    container = OurdContainer()
    pubsub = container.pubsub()
    pubsub.publish("notes_channel", {"message": "Hello World!"})

And of course, you can also do it on iOS too:

    [container.pubsubClient publishMessage:@{@"name": @"world"} toChannel:@"hello"];

* ODSubscription update

- ODSubscription now supports for both push notification and pubsub update automatically
- If the user didn't allow push notification permission, the app will still get the real time updates from pubsub channel

* Asset support

Upload an asset and associate it to a record

    - (void)imagePickerController:(UIImagePickerController *)picker
    didFinishPickingMediaWithInfo:(NSDictionary<NSString *, id> *)info
    {
        NSURL *url = info[UIImagePickerControllerReferenceURL];
        ODAsset *asset = [ODAsset assetWithName:@"profile-picture" fileURL:url];

        ODContainer *container = [ODContainer defaultContainer];
        [container uploadAsset:asset completionHandler:^(ODAsset *asset, NSError *error) {
            if (error) {
                NSLog(@"error uploading asset: %@", error);
                return;
            }

            self.photoRecord[@"image"] = asset;
            [container.privateCloudDatabase saveRecord:self.photoRecord completion:nil];
        }];
    }

* Asset support

To get it, you can call asset.url:

    [privateDB fetchRecordWithID:photoRecordID completionHandler:^(ODRecord *photo, NSError *error) {
        if (error) {
            NSLog(@"error fetching photo: %@", error);
            return;
        }

        ODAsset *asset = photo[@"image"];
        NSURL *url = asset.url;
        // do something with the url
    }];

* Geo-location support

Saving location in a record

    CLLocation *location = [[CLLocation alloc] initWithLatitude:22.283 longitude:114.15];
    record[@"location"] = location;

Query a list of records by distance

    CLLocation *distanceFromLoc = [[CLLocation alloc] initWithLatitude:22.283 longitude:114.15];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"distanceToLocation:fromLocation:(location, %@) < %f", distanceFromLoc, 400.f];
    ODQuery *query = [ODQuery queryWithRecordType:@"photo" predicate:predicate];


* Now planning

Access control

- Introduce role concept, such as admin, staff, user
- Allow developer to limit certain record access to different role of users

Command Line Interface

- Export / Import records
- Manage table schema
- Modifying records

* We target to open source Skygear to public in Dec.