Hi i am new to fix protocols, i was wondering how to process a NewOrderList from an ExecutionReport. As per a fix message document on the internet https://gainfutures.com/api/html/133e2886-5411-44b7-b781-2311a45ab540.htm i came to know that every order in the NewOrderList will be processed one at a time in the ExecutionReport.
From the above doc:
order statuses and trades are reported for individual orders, not for the list as whole.
Is there a way i can get the list of order details back from the ExecutionReport event listener using below
public void onMessage(ExecutionReport report, SessionID sessionID) {
// handler implementation
}
Related
I followed the Vaadin tutorial (Creating Collaborative Views) for broadcasting events and register on them.
Registration eventRegistration;
#Override
protected void onAttach(AttachEvent attachEvent) {
log.debug("In attach...");
UI ui = attachEvent.getUI();
eventRegistration= Broadcaster.register(
"eventName",
message -> ui.access(() -> {
log.debug("Request to refresh grid...");
presenter.refreshGrid();
ui.push();
}));
}
#Override
protected void onDetach(DetachEvent detachEvent) {
log.debug("In detach...");
if(eventRegistration != null) {
eventRegistration.remove();
eventRegistration = null;
}
}
Everything works except the fact that when refreshing the page, the logic in the onDetach() is not executed. After refresh, however, you will enter the onAttach() method. Because of this you are actually going to register several of 'the same' listeners without removing the previous one and you actually get a doubling of listeners. The onDetach() method is only accessed if you go to another menu item, for example.
You can find an example log below.
What is the Vaadin recommended way to remove these listeners before/during refresh?
The onDetach method should be called eventually.
No event is sent to the server when you close or refresh a tab, and as such the server is not aware that the old UI should be detached.
This is where the heartbeat requests come in. The UIs send heartbeat requests every 5 minutes per default, and if the server notices that the old UI has missed three heartbeats, it will be detached. Alternatively, it will be detached when the session expires.
In other words, the onDetach method should be called after about 20 minutes.
The reason no event is sent to the server when the tab is closed or refreshed is that this could prevent the tab from refreshing/closing while the request is being handled, which is bad user experience. Also, this wouldn't cover the cases where the computer is turned off or the network disconnected.
There is something called the Beacon API that could be used to notify the server when a tab is refreshed or closed without causing a delay in the browser. There is an issue for using this to immediately detach UIs.
I'd recommend using the Unload Beacon add-on: https://vaadin.com/directory/component/unload-beacon-for-vaadin-flow or a similar approach which is demonstrated in the Cookbook: https://cookbook.vaadin.com/notice-closed - essentially, it's executing the JavaScript snippet to add an event listener for Window's unload event:
ui.getElement().executeJs(
"window.addEventListener('unload', function() {navigator.sendBeacon && navigator.sendBeacon($0)})", relativeBeaconPath);
and the beacon is sent to a custom SynchronizedRequestHandler.
Simplest way to workaround the problem would be checking if eventRegistration is null before adding one.
#Override
protected void onAttach(AttachEvent attachEvent) {
log.debug("In attach...");
UI ui = attachEvent.getUI();
if (eventRegistration == null) {
eventRegistration= Broadcaster.register(
"eventName",
message -> ui.access(() -> {
log.debug("Request to refresh grid...");
presenter.refreshGrid();
ui.push();
}));
}
}
Check the other answer by Erik why calling of onDetach is delayed.
I have an Ecommerce website build with UCommerce. During the checkout process the user will be redirected to the payment portal for the payment.
I want to prevent users from adding new items in the basket while the user is in the payment portal. My current solution is to save the basket to a Session before redirecting the user to the payment portal.
Session["checkoutOrder"] = TransactionLibrary.GetBasket(!TransactionLibrary.HasBasket()).PurchaseOrder;
How can I overwrite the current basket with the one in the Session After the payment? This is to revert the basket to its original state before the payment.
I tried this:
[HttpPost]
public ActionResult ExecutePayment()
{
var order = Session["checkoutOrder"] as PurchaseOrder;
order.Save();
...
}
But I'm getting an error on order.Save():
Batch update returned unexpected row count from update; actual row count: 0; expected: 1
I'd just add to this as well that your Session["orderInProcess"] is an anti pattern in uCommerce. You may run into nasty exceptions as you're persisting NHibernate entities through requests which can/will lead to Session disposed exceptions. It may also lead to the initial exception that you're experiencing as you're actually by-passing the sesssion state of NHibernate.
Just use TransactionLibrary.GetBasket(!TransactionLibrary.HasBasket()).PurchaseOrder; every time you're retrieving your basket. NHibernate will take care of caching the order for you.
Then you can use order properties to save the state you're in.
var basket = TransactionLibrary.GetBasket(!TransactionLibrary.HasBasket()).PurchaseOrder;
basket["CheckoutInProcess"] = "True";
Best regards
Morten
I handled this differently since I have no way of reverting back the basket to its original state.
I decided to block the user from adding items in the basket when the payment is in process.
I created a session Session["orderInProcess"]=true before I redirect the user to the payment gateway.
Now every time the user tries to add a new item in the basket, I will check first if his current order is in process. like so:
[HttpPost]
public ActionResult AddToBasket(string sku, string quantity, string variant = null)
{
if (Session["orderInProcess"] != null)
{
if (bool.Parse(Session["orderInProcess"].ToString()))
{
return Json(new
{
Success = false,
ErrorMessage = "Order is currently in process."
});
}
}
.....
}
I hope this helps.
I have one resque job which is run at some event which finally publishes the message to RabbitMQ's exchange, how can I check in bunny(Rabbit MQ ruby client) that whether the message has been successfully published?
Using Acknowledgment or any way?
Thanks in advance!
When you execute the publish you are not sure that the message is published on the queue.
If you want to be sure you have to use you have to use publish confirm or tx transaction.
Read this post http://www.rabbitmq.com/blog/2011/02/10/introducing-publisher-confirms/
Note: By default the clients don't have any HA policy, you have to implement it. See the section Streaming Lightweight Publisher Confirms:
private volatile SortedSet<Long> unconfirmedSet =
Collections.synchronizedSortedSet(new TreeSet());
...
ch.setConfirmListener(new ConfirmListener() {
public void handleAck(long seqNo, boolean multiple) {
if (multiple) {
unconfirmedSet.headSet(seqNo+1).clear();
} else {
unconfirmedSet.remove(seqNo);
}
}
public void handleNack(long seqNo, boolean multiple) {
// handle the lost messages somehow
}
});
Note2: the message is never "put" inside an exchange, but always inside a queue.
Once the publish method returns, the message has published to the queue. There is no deferred action to publishing a message.
I am making an xmpp webchat application in Grails. I have a message listener that can log the recieved messages in console. But how can I do this dinamycally in a website ? I am new to webapp development so please dont down vote. I am guessing Ajax but not sure.
My listener:
private MessageListener messageListener = new MessageListener() {
#Override
public void processMessage(Chat chat, Message message) {
// 'from' and 'to' fields contains senders ids, e.g.
// 17792-1028#chat.quickblox.com/mac-167
// 17744-1028#chat.quickblox.com/Smack
String from = message.getFrom().split("#")[0];
String to = message.getTo().split("#")[0];
org.jivesoftware.smack.packet.Message.Type type = message.getType();
String tajp = type.toString();
println String.format(">>> Message received (from=%s, to=%s, type=%s): %s", from, to, tajp, message.getBody())
if (onMessageReceivedListener != null) {
onMessageReceivedListener.onMessageReceived(message);
}
}
}
I suggest you to take a look on the Events Push plugin. With that you can propagate your messages and notify your clients.
You will need:
Service that notify a new message
Controller method to call this service
Ajax request to the controller, sending the user message
JavaScript to handle incoming messages
I am new to webapp development
Web development is pretty different from desktop, so I suggest you to slow down to something more easy. There's other topics on StackOverflow that will introduce you to Grails.
Also, for webdev, it's essential to know about JavaScript, CSS and HTML for your front end.
I have question about managing transaction in asp.net application.
For example i have application for planning vacations.
Controller has form to approving vacations.
One user - click save and approve vacation ---- employee which want vacation has - 1 day
second user - clik save and approve vacation and ?
//pseudocode
public void ApproveVacation(int vacationId)
{
//pull vacationdata from db
var vacation = _dbContext.Vacations.FirstOrDefault(x => x.Id == vacationId);
if (vacation != null && vacation.State != approved) //
{
using (TransactionScope scope = new TransactionScope())
{
vacation.state = approved;
vacation.Employee.Days = -1;
_dbContext.saveChanges();
scope.complete();
}
}
}
And question is simple, is transaction enough for this scenario or I must use one of concurency technique?
Thanks
EDIT : Context is created one per request.
Transaction handles atomicity of the operation so if operation modifies multiple database records it will always result in consistent state where all records are correctly modified (if operation succeeds) or all changes are rolled back (if operation fails).
Concurrency handles possible modification of the same record by multiple processes / users because both could load original version of the record but one could save it first so when the second process tries to save a record it can silently override previous changes.
So what are you trying to handle in your code?
You already have an implicit transaction when calling 'SaveChanges' so there's no need for a transaction scope.
And also, if you would change several items you would need to start the TransactionScope before you retrieve the data.