from my understanding obited can do both comet and xmpp ? it is better than using typical comet library dwr right?
Orbited is a library to create 'realtime' applications that run in a web browser (it implements a technique known as Comet). More specifically is provides code and strategies to implement many protocols (xmpp, irc, stomp, amqp, etc) on top of what is known as a "web socket" - an object that abstracts away the many peculiarities of actually implementing Comet. Furthermore, Orbited describes, and in some cases provides, the back-end components (asynchronous webservers) that need to know and work with the front-end Comet clients.
Here is a little more detail on Comet and how Orbited plays in:
What makes Comet more complex to
implement (than making an Ajax app,
say), is that you need both the client
(a Comet javascript client) and the
server (an asynchronous webserver like
Twisted) working in conjunction, and
this is what you get with Orbited -
both the javascript client and the
server.
Related
I am really a beginner in delphi, as the client request the project to be done in delphi, so I have to ask to get some help as possible as I can. This project will be involved in HTML5 and websockets as well, so there are some questions I need your advices.
Sorry let me explain more, this application have two parts mainly, one is HTML5 client web app (this app will be loaded from web server, and run locally in browser), and the other is its service located in server. The HTML5 web app is doing some product editing job, as well send its final output to server, during this process, there will be many communications between client app and service, and I planed to use Websockets.
I did plan this application in HTML5 and Node.js before, but as client send request to ask for the Delphi XE as primary development tool also it will be compiled to DLL (ISAPI, have to be) at last. For consistency of UI, I also was required to use uniGUI (http://www.unigui.com/demo)for Delphi. Now I have these questions:
Is there any other way to do this application with HTML5 as web front exclude uniGUI in Delphi?
What good libraries support Websockets in Delphi?
What book you can recommend me to read, as I don't know Delphi at all.
Thanks.
1: yes, make a "single page app" (static html + js) and communicate with server using xml or json.
At least with indy 10 it is quite straight forward to implement static file serving (response.contentstream := tfilestream.create(sfilename) or something like that)
2: yes, if you search for it on google you will find some :)
WebSocket server implementations for Delphi
btw, I'm busy with delphi socket.io implementation, which makes it easier to use websockets instead of plain low level tcp-like websockets itself
Is there any other way to do this application with HTML5 as web front exclude uniGUI in Delphi?
First concept : HTML5 applications are a bunch of HTML files and JS's wich can be processed by browsers.
Second concept : You need an application that can bind HTTP queries and return files from the first concept.
Third concept (paradigm) : With first two concepts, a third concept arises. Dynamic HTML. What is dynamic HTML? HTML that generates at runtime at the backend server and/or at frontend with JS.
Solution :
Yes, with Delphi as a backend server you can manipulate and return HTML5 views, if you know (MVC paradigmn for example) you can program an HTTPServer application that binds HTTP request from network and responses your HTMLs and JS.
What good libraries support Websockets in Delphi?
You need a multilayer library. The best library I know is mORMot. mORMot is like a swiss razor for Object Pascal.
You can create an HTTP server with websocket published interfaces. mORMot's Site
What book you can recommend me to read, as I don't know Delphi at all.
I have more than 10 years with Delphi and Free Pascal and I didn't read a book at all. But I read a lot from internet and a lot of computer architecture and another languages like C and C++.
If you like Delphi there are tons of documentation via Internet. I cannot recomend you a book because I will lie you.
Just looking at Haskell and web frameworks and wondering if it would make sense to use Haskell's great threading/event functionality to power a platform for writing HTML5 and REST apps that expose an HTTP API for data and a WebSocket (with maybe SockJS support for appropriate fallback) API for events? It doesn't seem like the "big" web frameworks support WebSockets as a first-class citizen, though they seem to have a lot of other things going for them.
My concern is making use of available cores, which Haskell can do well, but also providing easy user integration on the server side for validation and server-side logic (maybe by embedding Lua or similar?). If one wrote this on the JVM, one could make use of multiple server-side language support and lots of libraries for this sort of thing.
I'm sure people are doing things like this in a one-off solution for their own applications but I'm thinking along the lines of a PaaS-type approach where one can write HTML5 apps with data (including proper synchronization for offline use) and eventing "for free" as a fundamental part of the platform. Most logic would reside in the browser but some could be run on the server with the appropriate hooks and a reasonable embeddability (JavaScript seems out of the question and not sure about embedding interpreters in Haskell as I'm only dangerously familiar with Haskell in general).
Part of the problem I've had with Haskell so far is that I'm not a Math guy. I didn't study CS in college and I'm a creative-type thinker. So a lot of the tutorials and documentation get me pretty lost, especially when dealing with the mathematical stuff.
Has anyone trod this path already? Am I late to the party? :)
Gregory Collins gave a tutorial at CUFP last year about using Snap to build an interactive chat website using long polling (not websockets). The source code is here.
In the websockets department, Jasper Van der Jeugt wrote a Haskell websockets library. It is available on hackage and comes with websockets-snap, which provides Snap framework support. There's also wai-websockets which provides integration with Warp.
I believe all of the major frameworks have some level of websockets support, so they should all be a fair choice based on your requirements. For Yesod, there's an example of creating a chat system (using eventsource, not websockets) available in the book:
http://www.yesodweb.com/book/wiki-chat-example
I'd like to implement an application with Scala and HTML5. My idea was to create a "local" client-server architecture: Scala handles the calculations and generates HTML5 as a GUI.
To my mind there are two possibilities
Use a Java/Scala framework that allows embedded HTML5. SWT for example has a browser widget. JavaFX seems good, too.
Distribute the program with a server and run it in a browser on localhost.
It would probably be most convenient to require an internet connection and forget about the localhost. Unfortunately an offline mode is necessary.
Now I would like to know how to get this right:
The first option seems easier to implement but I wonder: How can I communicate with Javascript without the HTTP protocol ?
The second approach was just an idea. Have you ever done something like this ?
If you've got advice or know a good framework please go ahead.
UPDATE :
I've just had an interesting idea: Could I use nodejs to create something like a server-server architecture ?
Right now the communication between Scala and Coffescript seems like the most problematic part. I still wonder how I could initiate an update from the Scala side of the application. A HTTP Request is a nice way to exchange data. Sadly to my knowledge in "standard" Coffeescript there would be no event hook to listen to server-side HTTP messages.
I've thought about using nodejs to listen to the server-sent data. Is this a good idea ?
With regards to the second option, you may wish to investigate the Play! Framework or Lift. They automate a lot of the work required to make a web application in Scala, including handling AJAX requests.
Although I haven't tried packaging either for local use, there was an earlier Stack Exchange question about packaging Lift which might be relevant. It should be possible with Play! as well.
I'd like to pick up a new tech for my toolbox - something for rapid prototyping of web apps. Brief requirements:
public access (not hosted on my machine) - like Google's appengine, etc
no tricky configuration necessary to build a simple web app host
DB access (small storage provided) including some kind of SQLish query language
easy front end HTML templating
ability to access as a JSON service
C# or Java,PHP or Python - or a fun new language to learn is OK
free!
An example app, very simple: render an AJAXy editable (add/delete/edit/drag) list of rich-data list items via some template language, so I can quickly mock up a UI for a client. ie. I can do most of the work client-side, but need convenient back end to handle the permanent storage. (In fact I suppose it doesn't even need HTML templating if I can directly access a DB via AJAX calls.)
I realize this is a bit vague but am wondering if anyone has recommendations. A Rails host might be best for this (but probably not free) or maybe App Engine, or some other choice I'm not aware of? I've been doing everything with heavyweight servers (ASP.NET etc) for so long that I'm just not up on the latest...
Thanks - I'll follow up on comments if this isn't clear enough :)
C# or Java,PHP or Python - or a fun new language to learn is OK
How 'bout Javascript? This place hosts server-side Javascript ticking most of your other boxes. So you can use the same language for client- and server-side stuff (which I find very handy). [Caveat: I only played with their service; seemed cool though. I use Javascript on the server-side on IIS and on Tomcat (via Rhino).]
For something bleeding edge - A new version of spring roo was released recently. With it you can create a great web app in 10 minutes. Supports GAE and GWT...
http://www.springsource.org/roo
xataface is a quick way to make a front end for a MySQL database.
It makes it easy to start an app quickly with dynamically created views and then you can change it to something very customized to your needs.
It simply needs a server service with MySQL and PHP.
I would like to know, what are the ways a web framework may be suitable for designing a RESTful app, in general.
One goal is for example to provide http request routing, so they are automatically sent to appropriate controllers. From architectural point of view, web framework based on MVC pattern are more suitable for REST.
What other features of web frameworks are helpful by building apps satisfying the REST constraints?
Is there any reason why you consider certain languages(python/java) or web frameworks(django/turbogears/jersey/restlets/...) as the most applicable ones?
I think the best way for a web framework to support a RESTful style is to automatically map the different HTTP verbs (GET, POST, PUT, DELETE, etc.) to corresponding methods on its controllers/request handlers. Most modern Python web frameworks do this out of the box, with the notable exception of Django (unless I missed a dramatic change).
a) You need very flexible routing.
b) You need to be able to easily generate links that correlate to resource controllers using templates and parameters.
c) The server should help you to parse all the http headers. e.g. Authorization headers, Accept headers, language headers, cookies, etags.
d) It should support serializing and deserializing all the commonly used mime types.
e) It should help parsing parameters from incoming URLs
f) It should help resolving relative urls based on the request url and any available BaseURL.
There are few ways that a web framework can NOT support REST. Its basically written with the HTTP model in mind; so just about any web framework works. The automatic routing you mention is a common expectation, but not strictly required for REST.
I would stress the ability to directly support definition of resources. In Ruby on RAils you can define a resource through scaffolding and you get a model with controller with restful verbs implemented also with views and support for different formats and readily avalaible views and routing with ids.
Aside from that having access to HTTP and supporting principles of HTTP is what you need.
I am not experienced enough to know about support in frameworks, but it would be also nice to have support for the caching and other request options.
On the “specific software recommendation” front, I've had people recommend Apache CXF as a framework for building RESTful services with Java. It appears to be even able to simultaneously support SOAP (which happens to be very useful for helping some of our customer base adopt the software). I'm still in the experimenting-with-it stage though, so you may be able to do better.