LiveQuery does not work with PFObjects secured with an ACL & when the where key has a Pointer

[tsanthosh]

First, thanks to the Parse team for making Parse open source and enhancing it constantly.

Environment:

• parse: 1.8.5
• parse-server: 2.2.11
• node: 4.4.5

Parse-server index.js:

...
var api = new ParseServer({
  databaseURI: databaseUri || 'mongodb://localhost:27017/xxxx-dev',
  cloud: process.env.CLOUD_CODE_MAIN || __dirname + '/cloud/main.js',
  appId: process.env.APP_ID || 'xxxx',
  masterKey: process.env.MASTER_KEY || 'xxx',
  serverURL: process.env.SERVER_URL || 'http://localhost:1337/parse',
  filesAdapter: new S3Adapter(xxxx),
  liveQuery: {
    classNames: ["Account", "GUEvent"]
  }
});
...
ParseServer.createLiveQueryServer(httpServer);

iOS Client:

class viewController: UIViewController {
    private var subscription: Subscription<GUEvent>!

    override func viewDidLoad() {
        super.viewDidLoad()

        subscription = GUEvent.query()!.whereKey("account", equalTo: accountObject).subscribe()
        subscription.handleEvent { query, event in
             print("Handling Event")
        }
    }
}

Live Query does not work:

• When the objects in GUEvent are secured with an ACL but works when the objects are publicly readable & writable.
• When the account is a pointer, I get *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid type in JSON write'.

So far Live Query works:

• When the objects in GUEvent are publicly readable and writable.
• When the where statement does not contain a pointer.

Any help would be greatly appreciated.

[tsanthosh]

I solved the ACL issue by passing the sessionToken to the subscribe method of the live query protocol.

>> In Operation.swift
internal enum ClientOperation {
    case Connect(applicationId: String, sessionToken: String)
    case Subscribe(requestId: Client.RequestId, query: PFQuery, **sessionToken: String**)
    case Unsubscribe(requestId: Client.RequestId)

    var JSONObjectRepresentation: [String : AnyObject] {
        switch self {
        case .Connect(let applicationId, let sessionToken):
            return [ "op": "connect", "applicationId": applicationId, "sessionToken": sessionToken ]

        case .Subscribe(let requestId, let query, **let sessionToken**):
            return [ "op": "subscribe", "requestId": requestId.value, "query": Dictionary<String, AnyObject>(query: query), **"sessionToken": sessionToken** ]

        case .Unsubscribe(let requestId):
            return [ "op": "unsubscribe", "requestId": requestId.value ]
        }
    }
}

>> In Client.swift & ClientPrivate.swift
self.sendOperationAsync(.Subscribe(requestId: $0.requestId, query: $0.query, sessionToken: PFUser.currentUser()!.sessionToken!))

This worked and I was able to get changes about objects which have been secured with an ACL.

[tsanthosh]

I also solved the pointer issue by replacing:

if let conditions: [String:AnyObject] = queryState?.valueForKey("conditions") as? [String:AnyObject] {
    print(conditions)
    self["where"] = conditions as? Value
}

with

if let rawConditions: [String:AnyObject] = queryState?.valueForKey("conditions") as? [String:AnyObject] {
    var formattedConditions = [String: AnyObject]()
    let keys = rawConditions.keys
    for eachKey in keys {
        if let pointer = rawConditions[eachKey] as? PFObject {
            formattedConditions[eachKey] = ["__type":"Pointer","className": pointer.parseClassName,"objectId": pointer.objectId!]
        } else {
            formattedConditions[eachKey] = rawConditions[eachKey]
        }
    }
    self["where"] = formattedConditions as? Value
}

in QueryEncoder.swift

At this stage I was super excited that I for the first time could do a pull request to update this repo. But what I found was PFObject received by the subscription handler was not readable i.e. instead of getting an object in the following format.

<Attendee: 0x7f8afce40440, objectId: ptnVOC4tKE, localId: (null)> {
    ACL = "<PFACL: 0x7f8afcebd670>";
    attendeeId = 585857109;
    barcode = 463895634585857109001;
    checkedIn = 0;
    customFields =     (
        "<CustomField: 0x7f8afa529840, objectId: 8Eri3BCtnf, localId: (null)>",
        "<CustomField: 0x7f8afa52aea0, objectId: rX21uQozak, localId: (null)>"
    );
    event = "<GUEvent: 0x7f8afa6a6720, objectId: Xsjhm2GrSZ, localId: (null)>";
    firstName = xxxxx;
    lastName = xxx;
}

I get.

<Attendee: 0x7f8afa6add50, objectId: sBA6bA6iwo, localId: (null)> {
    ACL =     {
        w6Pc41N1jN =         {
            read = 1;
            write = 1;
        };
    };
    "__type" = Object;
    attendeeId = 585857110;
    barcode = 463895634585857110001;
    checkedIn = 1;
    className = Attendee;
    createdAt = "2016-06-08T04:09:09.243Z";
    customFields =     (
                {
            "__type" = Pointer;
            className = CustomField;
            objectId = u62YrQ1QQL;
        },
                {
            "__type" = Pointer;
            className = CustomField;
            objectId = IXHYy0EQQn;
        }
    );
    event =     {
        "__type" = Pointer;
        className = GUEvent;
        objectId = Xsjhm2GrSZ;
    };
    firstName = xxxx;
    lastName = xxxx;
    updatedAt = "2016-06-08T09:06:06.709Z";
}

This looks like the results are from a REST API.

I then thought the above problem was due to me changing the QueryEncoder.swift but that was not the case. Even without using a pointer, I found that the PFObjects which were being downloaded after an event were not suitable for reading in iOS.

So, I am still stuck with this problem. Was super excited about Live Queries but now I am confused.

Any help will be much appreciated.

[vespakoen]

It looks like the results you get there in the last code block have pointers to other objects.
Did you expect the to be the full objects? in that case, did you use "includeKey" on the query?

I would love to see your pull request anyways, that way other people can test it out / give feedback =)

[agordeev]

Hi @tsanthosh ! Thanks for this research, I'm facing the same issue (parse-community/parse-server#2227). Did you make a pull request yet?

[agordeev]

Hi @tsanthosh ! I tried your method of passing sessionToken, but it doesn't seem working. The app doesn't get any event. Can you please check if your method is working for you? May be I missed something.

[ideastouch]

Hi Guys,
I think that the solution of @tsanthosh is a great start but fail when the query has some constraint as for example Less Than, etc (see link).
Therefore I added a block that it calls itself if necessary.

My change of

        if let conditions: [String:AnyObject] = queryState?.valueForKey("conditions") as? [String:AnyObject] {
            print(conditions)
            self["where"] = conditions as? Value
        }

is

        let objectDictionary = { (object:PFObject)->[String:String] in
            return ["__type":"Pointer","className": object.parseClassName,"objectId": object.objectId!] }
        var valueBlock:((AnyObject)->AnyObject?)!
        valueBlock = {(value:AnyObject)->AnyObject? in
            if let value = value as? PFObject {
                return objectDictionary(value) }
            if let value = value as? [String:AnyObject] {
                guard let (key,value) = value.first else {
                    fatalError("Value is bad formatted.")
                    return nil}
                guard let optional = valueBlock(value) else {
                    fatalError("Value is bad formatted.")
                    return nil}
                return [key: optional] }
            return value }

        if let rawConditions: [String:AnyObject] = queryState?.valueForKey("conditions") as? [String:AnyObject] {
            var formattedConditions = [String: AnyObject]()
            let keys = rawConditions.keys
            for (key,value) in rawConditions {
                formattedConditions[key] = valueBlock(value)
            } 
            self["where"] = formattedConditions as? Value
        }

I'm not sure if my solution when the guard fails is good, probably needs to be improved.
Anyway, if the guard's doesn't fail the query seems good formatted.
I wish our problems where solved with my solution above but looks like there is more issues.

The function parseObject<T: PFObject>(objectDictionary: [String:AnyObject]) throws -> T at ClientPrivate.swift doesn't take in account that the objectDictionary may have values that can be Parse Object. Therefore again we may use recursive calls.
I replaced the code

    let parseObject = T(withoutDataWithClassName: parseClassName, objectId: objectId)
    objectDictionary.filter { key, _ in
        key != "parseClassName" && key != "objectId"
        }.forEach { key, value in
            else { parseObject[key] = value }
    }

by

    let object = T(withoutDataWithClassName: parseClassName, objectId: objectId)
    try objectDictionary.filter { key, _ in
        key != "parseClassName" && key != "objectId"
        }.forEach { key, value in
            if let valueDictionary = value as? [String:AnyObject] {
                try parseObject(valueDictionary) }
            else { object[key] = value }
    }

Finally, looks like Live Query Server ignores where options in queries that has a constraint. In my case I tried using the constraint whereKey(String,notEqualTo:AnyObject). And the result was that I received everything.
I didn't check yet where the problem is, but I will try find it tomorrow.

[ideastouch]

I can not check what I said in my previous comments about what is going on with my request subscription, why the Server doesn't take in count the "notEqualTo" constraint. The request seems configured well, see below:

{
   "requestId":1,
   "op":"subscribe",
   "query":{"className":"Chat",
   "where":{
      "sender":{"$ne":{"className":"_User","objectId":"PQauDXIuWZ","__type":"Pointer"}},
      "appointment":{"className":"Appointment","objectId":"Z7J9CfWCZA","__type":"Pointer"}}}}

I can not check it because I can not succeed config the Parse Live Query with logs in VERBOSE mode. My configurations are as below:

var liveQuery = {
   logLevel: 'VERBOSE',
   classNames: ["Chat", "PFUser", "Appointment"] }
var api = new ParseServer({
  databaseURI: process.env.MONGODB_URI,
  cloud: process.env.CLOUD_CODE_MAIN,
  appId: process.env.APP_ID,
  clientKey: process.env.CLIENT_ID,
  masterKey: process.env.MASTER_KEY,
  serverURL: process.env.SERVER_URL,
  fileKey:  process.env.FILE_KEY,
  restAPIKey: process.env.RESTAPI_KEY,
  javascriptKey: process.env.JS_KEY,
  publicServerURL: process.env.SERVER_URL,
  emailAdapter: emailAdapter,
  liveQuery: liveQuery });

var port = process.env.PORT || process.env.PORT_SRVR

app.set('port', process.env.PORT || process.env.PORT_SRVR);
var server = require('http').createServer(app);
server.listen(app.get('port'), function () {
    console.log("Express server listening on port " + app.get('port')); });

// This will enable the Live Query real-time server
ParseServer.createLiveQueryServer(server, liveQuery);

Any help will be very welcome.

Best!

[andrewjedi]

When will this be fixed :(

[Treverr]

Do we have anymore information on this? A lot of my databases use pointers and makes the Live Query quite unusable.

[mmowris]

@Treverr , likely be a while. Doesn't look like this repo is being actively supported :(

[protspace]

The same for me. Result object from LiveQuery looks like REST API response object:

<Activity: 0x6080004ad8c0, objectId: E73ZyCFYGc, localId: (null)> {
    "__type" = Object;
    author =     {
        "__type" = Pointer;
        className = "_User";
        objectId = mEWnXHChMO;
    };
    className = Activity;
    createdAt = "2016-10-21T11:51:57.133Z";
    date =     {
        "__type" = Date;
        iso = "2016-10-21T15:01:00.000Z";
    };
    description = "";
    duration = 0;
    gender = 2;
    level = 1;
    location =     {
        "__type" = GeoPoint;
        latitude = "50.42923516132909";
        longitude = "30.51982775333386";
    };
    maxUsers = 20;
    name = 0;
    pendingUsers =     (
                {
            "__type" = Pointer;
            className = "_User";
            objectId = RGBrnHLBeC;
        }
    );
    updatedAt = "2016-10-22T15:31:24.366Z";
}

[flovilmart]

Can you try with the PR #76 ?

You can use it directly with CocoaPods (Swift3)

pod 'ParseLiveQuery', git: 'https://github.com/parseplatform/ParseLiveQuery-iOS-OSX', branch: "fix-object-decoding"