added_ios_shell.txt

# Directory layout:
# 
# Broadcasts/
#  |- parse/
#      |- cloud/
#      |- config/
#  |- iOS/        <----- downloaded code goes in here
#      |- Broadcasts.xcodeproj/
#      |- ...

added_opentok_library.txt

# Directory layout:
# 
# Broadcasts/
#  |- parse/
#      |- cloud/
#          |- main.js         <----- our functions go here
#          |- opentok/        <----- repository copied here
#              |- opentok.js
#              |- ...
#      |- config/
#          |- global.json

BroadcastsAppDelegate.m

@implementation BroadcastsAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Parse initialization
    [Parse setApplicationId:kParseAppId clientKey:kParseClientKey];
    
    [PFUser enableAutomaticUser];
    [[PFUser currentUser] saveInBackground];
    
    PFACL *defaultACL = [PFACL ACL];
    //...
}

//...
@end

BroadcastsCreationViewController.m

@implementation BroadcastCreationViewController
//...
- (IBAction)done:(id)sender {
    if (self.titleField.text.length > 0 && self.titleField.text.length < 25) {
        
        // Create the new Broadcast object
        PFObject *newBroadcast = [PFObject objectWithClassName:@"Broadcast"];
        newBroadcast[@"title"] = self.titleField.text;
        newBroadcast[@"owner"] = [PFUser currentUser];
        
        // Set the access control for the new Broadcast
        PFACL *acl = [PFACL ACLWithUser:[PFUser currentUser]];
        [acl setPublicReadAccess:YES];
        newBroadcast.ACL = acl;
        
        // Save the new Broadcast
        // ...
    }
    // ...
}
@end

BroadcastTableViewController.m

@implementation BroadcastTableViewController
// ...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
   // ...
   cell.dateLabel.text = [NSDateFormatter localizedStringFromDate:object.createdAt
                                                        dateStyle:NSDateFormatterMediumStyle
                                                        timeStyle:NSDateFormatterShortStyle];
   cell.ownerLabel.hidden = ![[(PFUser *)object[@"owner"] objectId] isEqual:[[PFUser currentUser] objectId]];;
   
   return cell;
}
// ...
@end

deploy.txt

# Move to parse directory
$ cd ~/projects/Broadcasts/parse

# Deploy
$ parse deploy
Uploading source files
Finished uploading files
New release is named v1

function-BroadcastViewController.m

@implementation BroadcastViewController
// ...
- (void)connectToBroadcast
{
  // ...
  // Connect to the Session as long as its not already connecting or connected
  if ( !( self.session.sessionConnectionStatus == OTSessionConnectionStatusConnected ||
         self.session.sessionConnectionStatus == OTSessionConnectionStatusConnecting   ) ) {
  
      // Get a token by calling Parse Cloud Code function
      [PFCloud callFunctionInBackground:@"getBroadcastToken"
                         withParameters:@{ @"broadcast" : self.broadcast.objectId }
                                  block:^(NSString *token, NSError *error) {
                                      if (!error) {
                                          [self.session connectWithApiKey:kOpentokApiKey token:token];
                                          [self configureView];
                                      }
                                  }];
        
  }
}
// ...
@end

main.js

// Import the opentok library from the subdirectory
var opentok = require('cloud/opentok/opentok.js').createOpenTokSDK('OPENTOK_API_KEY', 'OPENTOK_API_SECRET');


// Every Broadcast object should "own" an OpenTok Session
Parse.Cloud.beforeSave("Broadcast", function(request, response) {
  var broadcast = request.object;

  // If this Broadcast already has a sessionId, we are done
  if (broadcast.get("sessionId")) { response.success(); return; }

  // Otherwise, we create a Session now...
  opentok.createSession(function(err, sessionId) {
    // Handle any errors
    if (err) { response.error("could not create opentok session for broadcast: " + broadcast.id); return; }

    // ... and now save the sessionId in the Broadcast object
    broadcast.set("sessionId", sessionId);
    response.success();
  });
});


// This function can be called by any user who wants to connect to a Broadcast and a Token with the
// corresponding `role` will be generated. (Publisher for the Broadcast owner, Subscriber for anyone else)
Parse.Cloud.define("getBroadcastToken", function(request, response) {
  // Retrieve the Broadcast object for which the token is being requested
  var broadcastId = request.params.broadcast;
  if (!broadcastId) response.error("you must provide a broadcast object id");
  var broadcastQuery = new Parse.Query("Broadcast");
  broadcastQuery.get(broadcastId, {

    // When the Broadcast object is found...
    success: function(broadcast) {
      // Get the appropriate role according to the user who is calling this function
      var role = roleForUser(broadcast, request.user);
      // Create a Token
      var token = opentok.generateToken(broadcast.get("sessionId"), { "role" : role });
      // Return the token as long as it exists
      if (token) {
        response.success(token);
      // Handle errors
      } else {
        response.error("could not generate token for broadcast id: " + broadcastId + " for role: " + role);
      }
    },

    // When the Broadcast object is not found, respond with error
    error: function(broadcast, error) {
      response.error("cannot find broadcast with id: " + broadcastId);
    }
  });
});

// Helper function to figure out the OpenTok role a user should get based on the Boradcast object
var roleForUser = function(broadcast, user) {
  // A Broadcast owner gets a Publisher token
  if (broadcast.get("owner").id === user.id) {
    return opentok.ROLE.PUBLISHER;
  // Anyone else gets a Subscriber token
  } else {
    return opentok.ROLE.SUBSCRIBER;
  }
};

owner-BroadcastViewController.m

@implementation BroadcastViewController
// ...
- (BOOL)isBroadcastOwner {
    return [[(PFUser *)self.broadcast[@"owner"] objectId] isEqual:[[PFUser currentUser] objectId]];
}

// ...

- (void)sessionDidConnect:(OTSession *)session
{
  // Publish if this user owns this broadcast
  if ([self isBroadcastOwner]) {
    OTPublisher *publisher = [[OTPublisher alloc] initWithDelegate:self];
    [self.session publish:publisher];
  }
  [self configureView];
}

// ...

- (void)session:(OTSession *)session didReceiveStream:(OTStream *)stream
{
    if (![self isBroadcastOwner]) {
        __unused OTSubscriber *subscriber = [[OTSubscriber alloc] initWithStream:stream delegate:self];
    }
}
// ...
@end

setting_up.txt

# Install the `parse` CLI
$ curl -s https://www.parse.com/downloads/cloud_code/installer.sh | sudo /bin/bash

# Create and enter the project directory
$ mkdir -p ~/projects/Broadcasts && cd ~/projects/Broadcasts

# Set up a new parse project
$ parse new
Creating a new project in directory /Users/USERNAME/projects/Broadcasts/parse
Creating directory /Users/USERNAME/projects/Broadcasts/parse/config
Creating config file /Users/USERNAME/projects/Broadcasts/parse/config/global.json
Creating directory /Users/USERNAME/projects/Broadcasts/parse/cloud
Writing out sample file /Users/USERNAME/projects/Broadcasts/parse/cloud/main.js
Email: your@email.com
Password: 
1: Broadcasts
Select an App: 1