Rails, BOSH, XMPP should I manually increase rid? - ruby-on-rails

I have installed ejabberd on my system and gems 'xmpp4r', 'ruby_bosh'. I'm trying to make a chat client using strophejs in my views. Now I'm getting jid, sid and rid with BOSH and can save them in session using in view after this all.
So I'm connecting strophejs to http-bind like
var connection = new Strophe.Connection('http://localhost:5280/http-bind/');
and trying to attach my session like
connection.attach("#{bosh_session_jid}", "#{bosh_session_id}", "#{bosh_session_random_id}", function(status){
console.log(status);
});
bosh_session_jid, bosh_session_rid and bosh_session_sid are this identifiers that I should use and they are not changed.
So, at first connection attempt everything is connected and working ok and I even can send message. But after window reloading (F5 I mean) it's trying to reconnect and reattach process and sends me
POST http://localhost:5280/http-bind/ 404 (Not Found)
I read "Professional XMPP programming with JS and jQuery" and found line
Each subsequent request increments the RID by one.
So, do I need to increase rid by 1 in my cookies after each attach? Or then? Or I don't need to?

You must increment the RID yourself when refreshing or changing pages. I increment by 1 when loading the new page before attaching. Note: if you are storing in a cookie, you should update with every call returned with the new RID, so that your cookie is updated with the most current RID.

Related

Trigger or Javascript in processmaker?

The subject is:
I have connected one of my processes to an external sql database through Database Connection( very hard of course due to lack of sql connection!). In my dynaform i have two textbox that are named RefNumber and Value and also i have a button. i want to enter a number in RefNumber and press the button and related value to that number appears in Value (i have that number and its corresponding value in my database that i earlier connected).
So the first question is : Which one should i use ?Trigger or Javascript?
and the second question: what is the code?
Any comment is appreciated.
It depends on you whether you want to update your value at database side or backend side.
Also I would like to add that trigger sometimes fail due to bad connection issues or some random user shit error and it might happen that your data is updated and value is not incremented(updated). So I recommend not to use trigger, yes trigger saves time but sometimes it doesn't work.
And benefit of doing it at backend side is that if your data is not updated, failed, value will also not.
My solution is to create an API on server app processmaker(use plugin to create api). Or the server BackEnd will configure CORS enabled so that the client side can call the api.
In dynaform, use ajax to make request to api.

How to update a web page from requests made by another client (in rails)?

Here is my need:
I have to displays some information from a web page.
The web browser is actually on the same machine (localhost).
I want the data to be updated dynamically by the server initiative.
Since HTTP protocol is actually a request/response protocol, I know that to get this functionality, the connection between the server and the client (which is local here) should be kept open in some way (Websocket, Server-Sent Events, etc..)
Yes, "realtime" is really a fashion trend nowadays and there are many frameworks out there to do this (meteor, etc...)
And indeed, it seems that Rails supports this functionnality too in addition to using Websockets (Server-Sent Events in Rails 4 and ActionCable in Rails 5)
So achieving this functionnality would not be a big deal, I guess...
Nevertheless what I really want is to trigger an update of the webpage (displayed here locally) from a request made by another client..
This picture will explain that better :
At the beginning, the browser connects to the (local) server (green arrows).
I guess that a thread is executed where all the session data (instance variables) are stored.
In order to use some "realtime" mechanisms, the connection remains open and therefore the thread Y is not terminated. (I guess this is how it works)
A second user is connecting (blue arrows) to the server (could be or not be the same web page) and make some actions (eg. posting a form).
Here the response to that external client does not matter. Just an HTTP OK response is fine. But a confirmation web page could also be returned.
But in anyway the thread X (and/or the connection) has no particular reason to be kept.
Ok, here is my question (BTW thank you for reading me thus far).
How can I echo this new data on the local web browser ?
I see 2 differents ways to do this :
Path A: Before terminating, the thread X passes the data (its instance variables) to the thread Y which has its connection still open. Thus the server is able to update the web browser.
Path B: Before terminating the thread X sends a request (I mean a response since it is the server) directly to the web browser using a particular socket.
Which mechanisms should I use in either method to achieve this functionnality ?
For method A, how can I exchange data between threads ?
For method B, how can I use an already opened socket ?
But which of these two methods (or another one) is actually the best way to do that?
Again thank you for reading me thus far, and sorry for my bad english.
I hope I've been clear enough to expose my need.
You are overthinking this. There is no need to think of such low-level mechanisms as threads and sockets. Most (all?) pub-sub live-update tools (ActionCable, faye, etc.) operate in terms of "channels" and "events".
So, your flow will look like this:
Client A (web browser) makes a request to your server and subscribes to events from channel "client-a-events" (or something).
Client B (the other browser) makes a request to your server with instructions to post an event to channel "client-a-events".
Pub-sub library does its magic.
Client A gets an update and updates the UI accordingly.
Check out this intro guide: Action Cable Overview.

Keep RID in sync with multiple tabs for Strophe js connection

We are trying to implement a chat application where we are using strophe js for http-bind. Everything works fine, the only problem we are facing is with keeping connection alive with multiple tabs. I am not getting how to keep RID in sync when multiple tabs are open. Please help!!
Each requesting resource should have it's own resource name. In your instance, each tab should have it's own resource name and connection.
username#jabber.servername.com/tab1
username#jabber.servername.com/tab2
You will then need to cc any messages to each resource to keep them up to date with messages. See: http://xmpp.org/extensions/xep-0280.html. Each resource will then have it's own RID.

Delphi XE2 Datasnap Session Management - get session information after page reload

I am trying to determine how to retrieve session information using a Delphi REST DataSnap server.
I know that, when on the same client page, you have access to the current thread session using the TDSSession method GetThreadSession.
What I want to do, however, is store data in the session (putData) and still be able to retrieve it when the user moves from page1 to page2. At present, if the user moves to a different page, the session is lost and a new one is created, thus loosing the data in the session that I had previously set.
I have tried playing with TDSSessionManager.SetThreadSession(sessionid) - but I cant seem to get it working.
I've reviewed the much acclaimed Marco Cantu white paper, however, it doesn't provide a solution to this issue.
Any help I can get on this would be great - even if its just 'hey, this topic is covered in book X'.
Thanks!
The TDSSessionManager.SetThreadSession(sessionid) works with Session.sessionname.
Plus make sure your Lifecycle is set to Session (as stated by tondrej).
If you reconnect your client. a new session is started. So you want to keep your Datasnap connection open.
Or you can set the lifecycle to Server and mannage the client-sessions yourself.
Edit: Rest Servers are Stateless. So you need to store the page you are on on the Client. And Query the needed Page from the Server
You have to tweak the client side JavaScript to use a cookie to store session info.
See the last part of JavaScript Client Sessions
If you want to keep server side objects active for the session use the Session life cycle.
I believe what you need to do is set LifeCycle property of your TDSServerClass instance to Session (stateful). From your question it seems you are currently using Invocation (stateless).
Well, in Datasnap REST (GET, POST, DELETE, PUT) if you set your TDSServerClass to session, as is a REST in this case session is the same as invocation, is stateless (http://docwiki.embarcadero.com/RADStudio/Tokyo/en/Server_Class_LifeCycle#REST_Clients). It is right, you give the oportunity to all kind of clients to use your datasnap server with JSONs for example.
You need to create your owner model to session control to your REST server, or look for some framework to do this. In my case I use custom objects on lifecicle server (some cases with database too), and using tokens on request headers and other informations, I know if is the same client and I control too when the token expires and need to do new login, for exemple and I can give much more security too as on PUT resquests, only on records gave to client (it is only one case, but there are much others...). You need to resolve other way, not with classic way using TDSSession.

jquery .ajax request blocked by long running .ajax request

I am trying to use jQuery's .ajax functionality to make a progress bar.
A request is submited via .ajax, which starts a long running process. Once submited another .ajax request is called on an interval which checks the progress of this process. Then a progress meter is updated using this information.
However, the progress .ajax call only returns once the long running process has completed. Its like its being blocked by the initial request.
The weird thing is this process works fine on dev but is failing on the deployment server. I am running on IIS using ASP.Net MVC.
Update: Apparently, it is browser related because it is working fine on IE 7 but is not working on IE 8. This is strange because IE 8 allows up to 6 connections on broadband where IE 7 only allows 2 requests per domain.
Update2: I think it's a local issue because it appears to be working fine on another IE 8 machine.
The server will only run one page at a time from each user. When you send the requests to get the progress status, they will be queued.
The solution is to make the page that returns the status sessionless, using EnableSessionState="false" in the #Page directive. That way it's not associated with any user, so the request isn't queued.
This of course means that you can't use session state to communicate the progress state from the thread running the process to the thread getting the status. You have to use a different way of keeping track of running processes and send some identifier along with the requests that gets the status so that you know which user it came from.
Some browsers (in particular, IE) only allows two requests to the same domain at the same time. If there are any other requests happening at the same time, then you might run into this limitation. One way around it is to have a few different aliases for the domain (some sites use "www1.example.com" and "www2.example.com", etc)
You should be able to use Firebug or Fiddler to determine how many requests are in progress, etc.
Create an Asynchronus handler (IHttpAsyncHandler) for your second ajax request.
use any parameter required via the .ashx querystring in order to process what you want because the HttpContext won't have what you'll need. You barely will have access to the Application object.
Behind the scenes ASP.NET will create for you a thread from the CLR pool, not the application pool, so You'll have an extra performance gain with IHttpAsyncHandler

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