Parse Cloud Code Module For Layer

To incorporate Layer Authentication with Parse user management in your application, you will need to use Parse Cloud Code along with this module. This module takes care of generating a Layer Identity Token, and only requires you to implement a few lines of code.

##Installation If you haven't already, install the Parse command line tool that will let you manage the Parse Cloud Code for your application by following the directions outlined here.

To get the Layer Module, clone this repo, and place it in your Parse Cloud Code Directory in the 'cloud' folder:

    git clone https://github.com/layerhq/layer-parse-module.git

##Usage

###Creating your Cloud Function To use this module in your Parse Cloud Code, you have to require the module and initialize it with the proper IDs and keys.

Step 1: Start by navigating to the 'keys' folder in the repo you just cloned, and open the layer-key.js file. Copy the Private Key generated through the Keys section of the Dashboard into this file and save it. The contents of layer-key.js should look like:

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

Step 2: To require this module, open your main.js file and include this code at the top:

//main.js
var fs = require('fs');
var layer = require('cloud/layer-parse-module/layer-module.js');

Step 3: Next you must initialize the instance of this module with the proper Provider ID (developer.layer.com->Keys->Provider ID) and Key ID (developer.layer.com->Keys->Authentication Keys) generated in your Layer Developer Portal. Define them in the main.js file:

//main.js
var layerProviderID = 'YOUR-PROVIDER ID-HERE';  // Should have the format of layer:///providers/<GUID>
var layerKeyID = 'YOUR-KEY ID-HERE';   // Should have the format of layer:///keys/<GUID>
var privateKey = fs.readFileSync('cloud/layer-parse-module/keys/layer-key.js').toString();
layer.initialize(layerProviderID, layerKeyID, privateKey);

Step 4: Finally, you must create Parse Cloud function to call the generateToken function in the module. The Cloud function will look something like this in main.js:

//main.js
Parse.Cloud.define("generateToken", function(request, response) {
    var currentUser = request.user;
    if (!currentUser) throw new Error('You need to be logged in!');
    var userID = currentUser.id;
    var nonce = request.params.nonce;
    if (!nonce) throw new Error('Missing nonce parameter');
        response.success(layer.layerIdentityToken(userID, nonce));
});

Step 5: Make sure you actually upload your Parse Cloud code by executing the following command in the terminal:

$ parse deploy

The file structure should look like this when you're done:

├── layer-parse-module
│   ├── keys
│   │   └── layer-key.js
│   ├── layer-module.js
│   └── node_modules
│       └── jsrsasign
│           ├── Makefile
│           ├── README.md
│           ├── _t2.js
│           ├── lib
│           │   ├── footer.js
│           │   ├── footer.js~
│           │   ├── header.js
│           │   └── jsrsasign.js
│           └── package.json
└── main.js

###Calling your Cloud Function Once you have created the Cloud function with the layer-parse-module, you must call this function from your application and pass it the appropriate parameters (the userID and a nonce). The userID you are looking for is the objectID of the Parse User. Wherever you are requesting a nonce for authentication, your code should look like this:

####iOS

    // Request an authentication nonce from Layer
    [layerClient requestAuthenticationNonceWithCompletion:^(NSString *nonce, NSError *error) {
        NSLog(@"Authentication nonce %@", nonce);
       
        // Upon reciept of nonce, post to your backend and acquire a Layer identityToken  
        if (nonce) {
	        PFUser *user = [PFUser currentUser];
	        NSString *userID  = user.objectId;
	        [PFCloud callFunctionInBackground:@"generateToken"
	                           withParameters:@{@"nonce" : nonce,
	                                            @"userID" : userID}
	                                    block:^(NSString *token, NSError *error) {
	            if (!error) {
	            	// Send the Identity Token to Layer to authenticate the user
	                [self.layerClient authenticateWithIdentityToken:token completion:^(NSString *authenticatedUserID, NSError *error) {
	                    if (!error) {
	                        NSLog(@"Parse User authenticated with Layer Identity Token");
	                    }
	                    else{
	                        NSLog(@"Parse User failed to authenticate with token with error: %@", error);
	                    }
	                }];
	            }
	            else{
	                NSLog(@"Parse Cloud function failed to be called to generate token with error: %@", error);
	            }
	        }];
		 }
    }];

####Android

	layerClient.registerAuthenticationListener(new LayerAuthenticationListener() {
        @Override
        public void onAuthenticationChallenge(final LayerClient client, String nonce) {
            Log.d(TAG, "The nonce: " + nonce);

            ParseUser user = ParseUser.getCurrentUser();
            String userID = user.getObjectId();

            // Make a request to your backend to acquire a Layer identityToken
            HashMap<String, Object> params = new HashMap<String, Object>();
            params.put("userID", userID);
            params.put("nonce", nonce);
            ParseCloud.callFunctionInBackground("generateToken", params, new FunctionCallback<String>() {
                void done(String token, ParseException e) {
                    if (e == null) {
                        client.answerAuthenticationChallenge(token);
                    } else {
                        Log.d(TAG, "Parse Cloud function failed to be called to generate token with error: " + e.getMessage());
                    }
                }
            });
        }

        @Override
        public void onAuthenticated(LayerClient client, String userId) {
            Log.d("Successful Auth with userId: " + userId);
        }

        @Override
        public void onDeauthenticated(LayerClient client) {
            Log.d("Successful Deauth.");
        }

        @Override
        public void onAuthenticationError(LayerClient client, int errorCode, String errorMessage) {
            Log.d("Error: " + errorMessage);
        }
    });
        
    layerClient.authenticate();

You are now ready to build you app using Layer!

Troubleshooting Tips

1. Make sure that the layer-key.js only includes the private key and no other text.
2. Make sure you're setting the layerProviderID, layerKeyID, privateKey in the main.js not the layer-module.js.
3. Double check all the values in step #2. All values can be found under Keys in the dashboard.
4. Use the identity token validator under Tools in the Dashboard. It should help identify what the issue is.