I am trying to develope chat app. I have done created my web service with php and mysql.
The respond of web service is json format.
In swift part; i post some paramaters to web address and retrieve json respond then show the messages. I used use nstimer to post and retrieve the respond of my json respond. And if there is new message the show it.
I dont want to use nstimer for retrieve the message. Is there any better way to do that?
Thank you
If you have a REST-ful service, periodically polling is pretty much the standard way to do it.
Instead of polling, you could consider using a real-time update mechanism to either deliver the message, or else inform your client that you need to sync with the server. Google has developed a pretty robust, cross-platform solution that allows you to achieve this using the Push Notification protocol:
Google GCM XMPP
Take a look at this tutorial. It uses XMPP to pass messages back and forward.
But if you want to do it yourself just to learn you have two options:
Use a restful api where you GET and POST. The timer you have isn't bad. I would recommend changing the time when the app is in the background or not doing it at all. You can use something like parse to send PUSH notifications and reinitiate the GET calls when the user relaunches the app.
You could use WebSockets. WebSockets work a lot like BSD sockets except that they are wrapped in a HTTP(S) tunnel. With web sockets, you can check to see if the client you are looking for is connected. If they are, you just send them the message. If they are not, you do something like in option one using parse to send them a notification.
Hope that helps.
Edit:
Since parse is shutting down, you can use another service like it. I've never used kinvey but it seems that they also provide similar services as parse like the push notification mentioned above
Related
Creating a user, adding some record to collection in the DB, updating some stuff, etc..
All of these we regularly do with HTTP requests against REST api.
Think about making Event bus as server instead of REST api.
In that method, create user will be an event name: "CreateUser" instead of REST api endpoint: POST /users.
In reflect to any action done in the event bus, it will re-emit a following event telling to any body needed to know about, that the event was done.
If for example someone viewing the vehicles collection and another user just edit one of the columns or add a new vehicle instance, it will be reflected immediately to who views it online.
My question is if there attitudes like I mentioned above, if there some formally names for it, if it a good practice, if you know someone who regularly uses it, a framework or something etc. Does the socket.io server can handle and behave like http server in high workloads?
You can use websockets for this; they provide a bidirectional channel between client and server to send messages across. You will have to catch and parse the messages on each end yourself, as there is no additional protocol on top of them.
They don't hold state, so there is no knowledge of who is looking at what, or who got what. You could send the same update message to all connected clients and leave it to the client to use it or not.
You would have to reprogram your client code and the API endpoints, because it's a different way of doing things, and it can also do server push.
I have no idea about frameworks though, as I always use them without one. Websockets are fast, but server behaviour at high workloads depends on implementation, and I only have experience with the websocket server I wrote myself. I suppose the performance of the socket.io can easily be googled.
I'd like to integrate some phone status information into our crm system (calling, on the hook, busy etc). I would prefer not to build and maintain a fully functioning SIP server because i only need very basic information. Also, our VOIP provider already maintains a fully functioning SIP server, and they are way better at it. Basically, I would my crm sever to be kept up to date on anything the phone does? Would it be possible for our crm server to receive any SIP messages the phones send to our VOIP provider.
Can I tell a sip phone to do that?
Is such a feature supported by many phones?
Am i looking at this in the wrong way? I'm completely new to SIP and phone integration so there is a good chance there is an easier or better way to do this.
Thank you for your help!
You might use phone feature called Action URL. It is generating HTTP GET requests on events like on hook / off hook, these request can be used to pass events to CRM.
I'm researching methods to find ways for an event driven web application where a server can push data to the web page. Can I use APE ?? If so how can I use it and some resources please??
Thank You!!
People have been writing event driven servers since the dawn of the network. A simple google search will find your way.
However, since the client is a browser, your server must re-act upon keeping an HTTP connection open instead of simply doing socket work.
This is basically the only small difference than say an IRC server or a simple chat server.
I'm working on an iPhone application which will use long-polling to send event notifications from the server to the client over HTTP. After opening a connection on the server I'm sending small bits of JSON that represent events, as they occur. I am finding that -[NSURLConnectionDelegate connection:didReceiveData] is not being called until after I close the connection, regardless of the cache settings I use when creating the NSURLRequest. I've verified that the server end is working as expected - the first JSON event will be sent immediately, and subsequent events will be sent over the wire as they occur. Is there a way to use NSURLConnection to receive these events as they occur, or will I need to instead drop down to the CFSocket API?
I'm starting to work on integrating CocoaAsyncSocket, but would prefer to continue using NSURLConnection if possible as it fits much better with the rest of my REST/JSON-based web service structure.
NSURLConnection will buffer the data while it is downloading and give it all back to you in one chunk with the didReceiveData method. The NSURLConnection class can't tell the difference between network lag and an intentional split in the data.
You would either need to use a lower-level network API like CFSocket as you mention (you would have access to each byte as it comes in from the network interface, and could distinguish the two parts of your payload), or you could take a look at a library like CURL and see what types of output buffering/non-buffering there is there.
I ran into this today. I wrote my own class to handle this, which mimics the basic functionality of NSURLConnection.
http://github.com/nall/SZUtilities/blob/master/SZURLConnection.h
It sounds as if you need to flush the socket on the server-side, although it's really difficult to say for sure. If you can't easily change the server to do that, then it may help to sniff the network connection to see when stuff is actually getting sent from the server.
You can use a tool like Wireshark to sniff your network.
Another option for seeing what's getting sent/received to/from the phone is described in the following article:
http://blog.jerodsanto.net/2009/06/sniff-your-iphones-network-traffic/
Good luck!
We're currently doing some R&D to port our StreamLink comet libraries to the iPhone.
I have found that in the emulator you will start to get didReceiveData callbacks once 1KB of data is received. So you can send a junk 1KB block to start getting callbacks. It seems that on the device, however, this doesn't happen. In safari (on device) you need to send 2KB, but using NSURLConnection I too am getting no callbacks. Looks like I may have to take the same approach.
I might also play with multipart-replace and some other more novel headers and mime types to see if it helps stimulate NSURLConnection.
There is another HTTP API Implementation named ASIHttpRequest. It doesn't have the problem stated above and provides a complete toolkit for almost every HTTP feature, including File Uploads, Cookies, Authentication, ...
http://allseeing-i.com/ASIHTTPRequest/
Beside the obvious person to person instant message chat, What else have you used a Jabber server's functionality to enable?
Edit: links to working code to really show it off are particularly useful - and will be more likely to be voted up.
There are unlimited uses for XMPP/Jabber.
Take any message/data you want to send somewhere else and you can use jabber. Run a centralised logging service for distributed services? You can jabber the massage.
You want to check if your services/programs are running? XMPP presence will tell you. If you add custom status messages you can see exactly what is going on.
This is why Cisco has got into the game. Picture a server farm where each blade has a built in mini jabber client. On boot up it will register it's presence to the central server as awaiting work. The central server fires off some work in it's direction and it then changes it's status to "Busy". Another blade finished it's work and changes it's status back to "Available"... rinse and repeat.
When you combine the actual jabber messages with it's Out Of Band abilities, these servers can post where the results of the job can be found.
Anything you can think of needing to pass a message can be done with XMPP to some degree. Be this person to person, program to program, or any combination.
You could use a Jabber server to handle/broker messages between a client application and another server application.
It can actually be pretty effective.
Not me but Martin Woodward used jabber to control a "build bunny" that displays the current status of the build server.
http://www.woodwardweb.com/gadgets/000434.html
XMPP is good for sending messages back and forth between computers that don't need to be broken into chunks. They also can't be terribly big. If you use the right library, it can be pretty easy to set up.
Sending messages to a web page. Proof-of-concept: esagila.com
I plan to use it to receive notifications from my system, such as:
Process did not finish
Report was not generated on time
User needs help
I already receive many of these messages as email. But receiving an IM could be much more effective.
You might want to look at Vertebra which is...
a framework for orchestrating complex processes in a Cloud. It is designed with an emphasis on security, fault tolerance, and portability.
From the knowledge base:
Why was XMPP chosen for Vertebra?
XMPP based instant messaging can be a good alternative to search engines for information that is small, complete in itself and required frequently and repeatedly. For example, your daily horoscope - you require it daily and it is not large.
To see an example of this add astro#askme.im to your list of contacts in your jabber client (Gmail Chat/Gtalk/or any other Jabber client) and then initiate chat with this contact by sending the word "help".
Also see www.askme.im for a whole list of chat based solutions.
I've used Jabber in the past to get email notifications. Nowadays I use it for low-priority nagios notifications, it is very useful and way cheaper than SMS:
We use xmpp as both a 'bus' and a real-time API at http://superfeedr.com
Iowa State University Department of Agronomy has created this with Jabber: http://mesonet.agron.iastate.edu/iembot/
If you're a weather freak like I am, this is VERY cool stuff!
Apple implements mobileme's push service using Jabber/XMPP's subscription services to send push notifications. That is the most widespread use of Jabber for non-IM purposes I know of. This article has more details.
My friends have also built a Jabber python bot, which is kinda cute but not all that useful :-)
Edit
The most recent Next Big Thing, Google Wave, uses Jabber under the hood. Further illustrates the power of the protcol.
We have used XMPP and BOSH to enable users to communicate with a webbrowser directly and in realtime from their phone.
For example Code you can view our open source API
The vooices site also has live examples where you can control a map and play a game using your phone via your web browser: http://www.vooices.us/
I've always thought XMPP would be a good way to deliver SNMP data. OIDs are really painful, much of the system is insecure, and the SNMP traps never work quite like you want them to. With an XMPP server in the middle and a smart component to make some choices, you can use it to send out jabber or other notifications, kick off restart jobs, update web pages, or whatever else you need.
The XML data is pretty small in this case, and you can have the one XMPP server both talk to humans in message stanzas, or computers with the same protocol.