Just curious, if you were to build an instant message client for the Mac what existing API or service would you use to handle the transfer of messages from one user to another? I am looking for something that can be used in conjunction with objective-c and is compatible with other popular messaging services such as MSN, Yahoo, Aim, gtalk, etc. I don't want to host the service, but rather connect to existing services and use their "pipes".
Thanks
There are many Instant messenger protocols out there.
There is a good bet you could find a Java API for which protocol you would like to use like the XMPP Java API.
Or
for C or C++ you could use the libpurple library.
Your question lacks a lot of informations, so it's rather hard to answer. Please add some details on your requirements. What protocols do you need, what functionality, what development language do you use?
As a start:
Adium has been released under the GPL, thus you can use the code in your own projects as long as the license fits your needs.
http://trac.adium.im/
Another option, if you don't want to implement multiple networks but prefer to use a single protocol where the server provides gateways to other networks you can also check out Jabber/XMPP libraries that are available for the mac.
http://www.google.de/search?q=jabber+library+mac&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:de:official&client=firefox-a
Related
We have a traditional VB application which are used for Organization operations. Now we are building a Hybrid application developed by using HTML5,CSS and Javascript which is targeted on Google Chromium desktop container. Now we are planning to provide a way to exchange large data like employees records between both of these 2 applications. Now my specific question is
What are the different ways to achieve communication between Chromium desktop container and VB application to exchange large chunks of data?
Sounds a bit painful no matter what.
Chrome Apps Architecture
All external processes are isolated from the app.
This would seem to suggest the obvious course is to use cloud data services, whether on public or private clouds.
I suspect that for political as well as practical reasons no cloud vendor goes to the trouble to provide VB/VBA-friendly APIs for their services. Mainly nobody wants to deal with support issues from the teeming hordes of casual coders the VB community is saddled with.
The VB6 community hasn't stepped up and taken care of this themselves either.
If you can limp along with the burdens of ".Net Inter Clop" (the usual MS answer) that might be a way to exploit existing API implementations.
Otherwise you might roll your own cloud. I see a few obvious services you'd want to implement in your cloud with lightweight APIs easily implemented in both of your development ecosystems:
Bulk Storage. I suggest WebDAV, which IIS supports. If you eschew the locking features then WebDAV API implementations are pretty easy in both JS and VB. Or buy (or scrounge open source) implementations of a more complete WebDAV client library.
DBMS. Pick any, implement a simple REST-like XML over HTTP API. Relatively easy to implement.
Push Notifications. I'd write a custom service accepting long-duration TCP connections from all clients, and with protocols and workflow à la Amazon SNS or Google Cloud Messaging. Such a service would be generally light in resource consumption but you'd probably want a dedicated box with OS tweaks to support a large number of active TCP connections.
Maybe optionally a message queue service?
Nothing novel here, these are all well established patterns.
All of the tools to do that are pretty off-the-shelf whether you want your cloud servers to be based on Windows, Linux, or generically Java anywhere.
Most of the effort will probably go into developing a consistent authentication model, access control model, and of course an integrated administration interface, monitoring, and logging to help keep operating overhead low and uptime high. Well, that and developer docs and training.
Ok, still a lot of work. Too bad there isn't a "cloud in the box" with the API libraries you'd need that you can buy off the shelf today.
Or perhaps I'm missing something obvious?
I'm interested in having clients, on iOS/OS X platforms using Cocoa, having secure transaction with a dedicated server. I'm looking for the easiest and most 'proper' use of the fancy highly abstracted APIs that Apple has developed. An example of what I'm talking about with those "fancy" APIs is that https is implemented "for free" and could suit my purposes - except that I don't know how to implement the corresponding server portion of that?
The network messages basically need to be a secure session where a client can create an account, or log in with that account, can send a request to the server, and receive a response from the server. The traffic is low volume, latency is OK, most important thing is to implement confidentiality and to make my software effort as short as possible.
The server will be on FreeBSD and will either run Cocoa via Cocotron or can use some other technology you mention that would make development faster. The computation being done on the server is minimal, requires db intfc, etc.
On the client side, NSURLRequest and NSURLConection all support HTTPS mode. You could also try third party libraries such as ASIHTTPRequest.
On the server side, I'm not sure what you mean by "The server will be on FreeBSD and will either run Cocoa via Cocotron". Are you saying that your server will be written in Objective-C and using Cocoa API? I'm not really sure why you want to do something like that. If the code on server is minimal, why not use the Apache server combined with mod_ssl and perhaps PHP to get it done? PHP is excellent for quick and dirty server. You can also use django / rails and other established frameworks (all of which support HTTPS) if those suit your need better.
EDIT: I forgot to include the prime candidate for web applications: JSON over HTTP/REST + Comet. It combines the best features of the others (below)
Persevere basically bundles everything I need in a server
The focus for Java and such is definitely on Comet servers, but it can't be too hard to use/write a client.
I'm embarking on an application with a server holding data, and clients executing operations which would affect this data, and thus require some sort of notification across all interested/subscribed clients.
The first client will probably be written in WPF, but we'll probably need to add clients written in other languages, e.g. a Java (Swing?) client, and possibly, a web client.
The actual question(s): What protocol should I use to implement this? How easy would it be to integrate with JS, Java and .NET (precisely, C#) clients?
I could use several interfaces/protocols, but it'd be easier overall to use one that is interoperable. Given that interoperability is important, I have researched a few options:
JSON-RPC
lightweight
supports notifications
The only .NET lib I could find, Jayrock doesn't support notifications
works well with JS
also true of XML-based stuff (and possibly, even binary protocols) BUT this would probably be more efficient, thanks to native support
Protobuf/Thrift
IDL makes it easy to spit out model classes in each language
doesn't seem to support notifications
Thrift comes with RPC out of the box, but protobufs don't
not sure about JS
XML-RPC
simple enough, but doesn't support notifications
SOAP: I'm not even sure about this one; I haven't grokked this yet.
seems rather complex
Message Queues/PubSub approach: Not strictly a protocol, but might be fitting
I hardly know anything about them, and got lost amongst the buzzwords`-- JMS? **MQ?
Perhaps combined with some RPC mechanism above, although that might not be strictly necessary, and possibly, overkill.
Other options are, of course, welcome.
I am partial to the pub/sub design you've suggested. I'd take a look at ZeroMQ. It has bindings to C#, Java, and many other platforms.
Bindings list: http://www.zeromq.org/bindings:clr
I also found this conversation on the ZeroMQ dev listing that may answer some questions you have about multiple clients and ZeroMQ: http://lists.zeromq.org/pipermail/zeromq-dev/2010-February/002146.html
As XMPP was mentioned, SIP has a similar functionality. This might be more accessible for you.
We use Servoy for this. It does automatic data broadcasting to web-clients and java-clients. I'm not sure if broadcasts can be sent to other platforms, you might be able to find an answer to that on their forum.
If you want to easily publish events to clients across networks, you may wish to look at a the XMPP standard. (Used by, amongst other things, Jabber and Google Talk.)
See the extension for publish-subscribe functionality.
There are a number of libraries in different languages including C#, Java and Javascript.
You can use SOAP over HTTP to modify the data on the server and SOAP over SMTP to notify the subscribed clients.
OR
The server doesn't know anything about the subscription and the clients call the server by timeout to track updates they are interested in, using XML-RPC, SOAP (generated using WSDL), or simply HTTP GET if there is no need to pass back complex data on tracking.
So far I have seen non-Java client support only for open source message brokers like Apache ActiveMQ, JBoss HornetQ and Open Message Queue (OpenMQ).
Are there also closed-source products like WebSphere, WebLogic or Tibco which offer non-Java access to their MOM brokers, using a documented wire protocol (opposite to a closed-source binary client library) which allows to write clients in other languages?
This is getting more interesting as products (like WebLogic) are available in the (EC2) cloud so that developers can use the cloud instance to develop and test a client application without the need to purchase and install the full version.
I don't have a definitive answer because I specialize in WMQ exclusively. However, I believe the answer is "no" for the most part. (More on that in a minute.)
Regarding WMQ IBM makes available exit points to tailor the behavior of the channels, API calls and authorizations. Exits are very well documented and perform narrow functions within the scope of a particular action - i.e. receive a message, initiate a connection, etc. These are written in C and, more recently, Java. For the most part these are unused and customers I talk to generally cite complexity. They want something customizable through configuration and not through low-level code. I suspect other MOM vendors experience similar requirements from customers.
What does this have to do with your question? My take on this is that if customers are reluctant to code up exits with limited function, it seems far fetched that they would code up a full-featured and robust client that supports reliable message delivery, one- and two-phase commit, client-side exits, diagnostics, and all the other functionality that WMQ channels provide.
Assuming that this task was undertaken by an open-source team capable of that level of code, who would support it? the MOM vendors currently provide end-to-end support when using their proprietary clients. The notion of how a trouble ticket might be resolved when using a third-party client that is community-supported is a bit scary to many customer. For example, IBM supplies add-ons for WMQ called SupportPacs. Although there are SupportPacs that are fully supported and are considered product extensions, some of the SupportPacs are provided as-is. Many of my customers won't run as-is code even when it is supplied by the vendor.
Finally, there is the notion of the interface contract. WMQ supports a few verbs with a lot of options. The underlying channel protocol is MUCH more complex. When WMQ v7 came out, the channels had considerable new functionality and tuning. this was possible at this scale because the internals are not exposed to clients and so IBM was able to make massive changes without fear of negative impact to 3rd party clients. Exposing all of that would create dependencies on an order or two higher magnitude than exist with just the API's exposed.
So, according to my theory (I don't pretend to speak for the MQ development team here) the big MOM vendors have a vested interest in not exposing their channel protocols to independent developers. The new wrinkle here is AMQP which I alluded to above. It defines the wire protocol and allows each vendor to code a compliant product. Although this provides the opportunity you describe for open-source solutions, the ability of any one implementation to improve the product is limited by the fact that they don't own the protocol. For the time being though I don't expect you'll find any of the big MOM vendors exposing their wire protocols for 3rd party development. That said, this is just a guess and if I'm wrong, I'm sure someone here will jump in and provide the counter-example.
I have a socket app that needs to have support for SOCKS 4 and 5 proxy connections, since my users may be behind firewalls. I am using WPF and C# 3.5 SP1. I see no options in the default Socket class for proxys, do I have to roll my own?
I'd prefer not to use 3rd party libs if possible - how difficult is it to enable proxy support with a standard C# Socket?
It is not terribly hard but you have to read through a couple of RFCs. You need to read the RFC spec on Socks v4, Socks v4a and Socks v5. I wrote a library that will do all the work for you but if you would rather write you own that is cool too. My library was mentioned in the previous post (Starksoft). You can implement the Socks protocol using a standard TcpClient object or a Socket connection. The TcpClient is easier. You simply need to send the commands immediately after connection to your proxy server. Those command will instruct the proxy server what final end point you are interested in connecting to. There is also specs for a UDP Socks connection but it sounds like you won't be needing that.
You can find all the RFCs and generation information on wikipedia. I can't post more because this crazy stackoverflow site limits the number of hyperlinks I am allowed to 1 since I am not a regular user. Very annoying.
http://en.wikipedia.org/wiki/SOCKS
Finally, you can rip off my code if you like since it is under the MIT license and I let you do that kind of thing. :) Take at look at my class Socks4ProxyClient.cs that implements the Socks v4 protocol. The method of most interest to you is named SendCommand() located on line 282. You can find my code at Google Code. Search for Starksoft. Or you can go to my web site directly and I have link to the source code in Google.
Socks5 implementation is a little trickier with more options to specify and a little more chatter to the server but basically very similar to Socks4.
Good luck and you should implement a solution yourself if you want to learn Socks. So, kudos to you!
Benton
You could ask google for some info. One of the first links will lead you to Mentalis.org and their free proxy implementation. They were once well known for their free network and security stuff but the projects seem to not being maintained for a while.
But it might be worth a look anyway.
I know you said that you did not want to use 3rd party librarys if possbile, but I would like to recommend this http://www.starksoft.com/prod_proxy.html.