Setting Up Push on Backend Application
===

A RhoConnect push to the client consists of executing a RhoConnect ping call. There are three ways to execute a ping call: you can use the RhoConnect REST API to remotely call the ping, perform the ping job directly in a blocking ruby call, or enqueue a resque job to ping asynchronously.

## Pushing Remotely with the RhoConnect REST API

You can trigger a push remotely using the [RhoConnect API Ping method](/rhoconnect/rest-api). This is useful if you want to fully control the push process from a remote server, such as when you use a RhoConnect plugin to connect your backend application to the RhoConnect server application.

**NOTE: If you want to sync all the sources, use 'all' for the source list (the soure_name parameter) instead of a comma-separated list of the RhoConnect application source names to sync.**

### Example of Ping for Ruby Backend Application

As an example, here is how to send a PUSH message to all the devices of the specified user(s) from a Ruby backend app:

	:::ruby
	# :message - message which will be used to display notification popup dialog on the device
	# :badge - iphone specific badge
	# :sound - name of the sound file to play upon receiving PUSH notification
	# :vibrate - number of seconds to vibrate upon receiving PUSH notification
	# :sources - list of data source names to be synced upon receiving PUSH notification
	ping_params = {
      :api_token => token,
      :user_id => [array_of_users],
      :sources => source_name,
      :message => 'hello world',
      :vibrate => 2000,
      :sound => 'hello.mp3'
    }

	RestClient.post(
	  "#{server}/rc/v1/users/ping", ping_params.to_json, 
	  { :content_type => :json,
		'X-RhoConnect-API-TOKEN' => @api_token }
	)

### Example of Ping for .NET Backend Application

As an example, here is how to send a PUSH message to all the devices of the specified user(s) from a .NET backend app:

    private static bool perform_ping(String method, String source_name, String the_message, String vibrate_time, String sound_file,  Hashtable reqHash)
        {
            // add meta information
            reqHash.Add("user_id", [array of users]);
            reqHash.Add("source_id", source_name);
            reqHash.Add("message", the_message);
            reqHash.Add("vibrate", vibrate_time);
            reqHash.Add("sound", sound_file);

            JavaScriptSerializer js = new JavaScriptSerializer();
            string requestBody = js.Serialize(reqHash);
            
            Uri address = new Uri(_endpoint_url + "/rc/v1/users /ping");
            HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;
            request.ContentType = "application/json";
            request.Method = "POST";
			request.Headers.Add("X-RhoConnect-API-TOKEN", _api_token);

            byte[] byteData = UTF8Encoding.UTF8.GetBytes(requestBody);
            request.ContentLength = byteData.Length;
            using (Stream requestStream = request.GetRequestStream())
            {
                requestStream.Write(byteData, 0, byteData.Length);
            }
            using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
            {
                ;
            }

            return true;
        }

### Example of Ping for Java Backend Application

As an example, here is how to send a PUSH message to all the devices of the specified user(s) from a Java backend app:

	:::java
	private boolean performPing(String method, String sourceName, HashMap<String, Object> hash) {
		hash.put("api_token", apiToken);
		hash.put("source_id", sourceName);
		hash.put("user_id", partition);
		hash.put("message", "hello world");
		hash.put("vibrate", "2000");
		hash.put("sound", "hello.mp3");
		

		HttpHeaders headers = new HttpHeaders();
		headers.setContentType(MediaType.APPLICATION_JSON);				 
		HttpEntity<Map> entity = new HttpEntity<Map>(hash, headers);

		ResponseEntity<String> response = restTemplate.exchange(
				endpointUrl + "/rc/v1/users/ping", 
				HttpMethod.POST,
				entity,
				String.class);
		HttpStatus statusCode = response.getStatusCode();

		return(statusCode.value() == 200);
	}

## Pushing Directly from a RhoConnect Source Adapter

When you use a RhoConnect source adapter to connect to your backend service, you can use the PingJob.perform method to perform a ping on your mobile client.

	:::ruby
	PingJob.perform(
	  'user_id' => current_user.login,
	  'sources' => ['Product','Customer'],
	  'message' => 'hello world',
	  'vibrate' => 2000,
	  'sound' => 'hello.mp3'
	)

Let's say we want to execute a ping for the `current_user` at the end of your RhoConnect source adapter query.

	:::ruby
	def query(params=nil)
	  parsed = JSON.parse(RestClient.get("#{@base}.json").body)

	  @result = {} 
	  parsed.each do |item|
	    @result[item["product"]["id"].to_s] = item["product"]
	  end if parsed    
	  PingJob.perform(
	    'user_id' => current_user.login,
	    'sources' => ['Product'],
	    'message' => "There are new products!",
	    'vibrate' => 2000
	  )
	  @result
	end

## Queuing a Resque Job to Push Asynchronously

To queue a ping that is executed asynchronously in a job, you can have PingJob queued from anywhere in your RhoConnect application (i.e. at the end of another job or adapter query method).

	:::ruby
	Resque.enqueue(
	  PingJob,
	  'user_id' => current_user.login,
	  'sources' => ['Product','Customer'],
	  'message' => 'hello world',
	  'vibrate' => 2000,
	  'sound' => 'hello.mp3'
	)

**Note: For this job to execute, you will need to have a resque worker running.  See running [async jobs](/rhoconnect/async-jobs) for more information.**