I'll try to keep this brief. Hope to get some help or directions about this. Im creating a webapp for a customer that needs notifications for something like this case.
A client register to the hotel at 10PM for 12 hours, this person will left the hotel at 10AM. My client wants a way to display a notification when there is 10 minutes to run out of time for the customer at hotel. I mean, at 9:50AM, the system should display a notification saying: "Time for Room 212 it's gonna expire soom. Contact him and ask if he wants extra hours".
Im using PHP and JQuery for this mission. The whole thing is to figure out a way to check the end-time for the customer and display a notification 10 mins before that end-time. I don't know how to keep "checking the end-time" constantly and display the notification when is the right time.
I hope i've explained my self about this. Any direction, anything that works for this, anything will be very welcome.
Thanks in advance.
I advice you to use jQuery timers plugin for actions explained in previous post.
As way for you is creating notificator that will ask server every minute for the messages. It will be like that:
$(document).everyTime('1min', function(){
// your request function
});
In your request you don't need send any data (of course if your server knows your timezone).
And server will respond you after DB reques as FALSE if no notifications at the time or with notification / array of notifications (of course as json-object).
Good Luck!
setInterval(function() {
// check the time, if it is 10 min before end-time, display notification
}, 1000);
Related
So I've this project for school who is about "triggers" for social networks.
Let me explain:
- A user can register for our application and login
- He can sign in for multiple services like Facebook, Twitter etc.
- Then their is what we call triggers, once he signed in on our application and registered his services, everytime he will post something on twitter for example my server will see it and post it on Facebook aswell.
I knew nothing about node.js a month ago so I'm kinda new to all this async stuff but I took some course to help myself. So far so good I can now manage users etc, (I've again some research to do with oauth).
My biggest problem is this "real-time" update on our server.
I mean I searched on the internet and saw this what we call polling (?), the idea to make request frequently to a server every X seconds.
So with a bit a sudo code this what I tought it would look like:
For each User
asynchronously watch for every update on Facebook and Twitter for
this User
So I did some research about performing request every each second and found about setInterval and setTimeout
const watchSocialMedia = setInterval(function(){
Users.forEach(user => {
User.watchAndPostAnyNewPost() //
}
}, 60000);
So I put some dummy data to illustrate.
Problem is I don't think It'll be done asynchronously ?
I mean the ideal is if I could put one time for each user a 'watcher' like saying
For each User
User.watchAndPostAnyNewPost()
where watchAndPostAnyNewPost() look like this
class User () {
...
const watchAndPostAnyNewPost = setInterval(function(){
fetchFacebook();
fetchTwitter();
}, 60000);
}
So each user have his own setInterval function running on him to check if he posted anything
Anyone can tell me if it's even possible ? :-)
Thanks a lot for reading me !!!
I have multiple heroku dynos and a chat app. When a user logs in, their status is set to "online" in MongoDB. However, if a server crashes, their status will still be set as online. How can I update the user status to be "offline" when a server crashes?
If I only had one dyno, this would be easy. I'd just update every user to be "offline" when the server starts. Unfortunately, this is not possible with multiple servers.
As per our chat and comments.
The best option is to go with checking against last activity. So seeing when the last message was sent and if it happened within the last let's say 5 minutes they are online if there were no activity mark them as offline.
Like I mentioned in the comments, if you are not storing a date_created on the messages documents you will not have to change anything because _id stores the timestamp
ObjectId("507f191e810c19729de860ea").getTimestamp()
that returns this Date object
ISODate("2012-10-17T20:46:22Z")
This answer is another option (if you are wanting to keep them as online even if they are not sending messages):
If you would like to know they are still active even when they're not jumping from page to page, include a bit of javascript to ping your server every 60 seconds or so to let you know they are still alive. It'll work the same way as my original suggestion, but it will update your records without requiring them to be frantically browsing your site at least once every five minutes.
var stillAlive = setInterval(function () {
/* XHR back to server
Example uses jQuery */
$.get("stillAlive.php");
}, 60000);
Hi I'm new user to atmosphere, and set up a simple test that worked fine. We used long-polling, and the behavior was that my client would send the server a GET that would stay open until:
data was returned by the server
a minute elapsed
in both cases, the client would immediately send another GET for the server to hold open. Most of the time no data was sent, so every minute the GET would be "refreshed." I assumed this was the default behavior because maybe certain browsers or networks would shut off a GET that exceeded a certain time limit, so this was a way to avoid that.
Question:
Is this refresh controlled by the client or the browser? I poked around and couldn't figure out if the client was closing the connection on its own and sending a new request, or if it was the server.
The reason I ask is that the server got deployed, and now that refresh is no longer occurring. My client GET now stays open to the full 5 minute (default) timeout and then throws the timeout event, then reconnects for another 5 minutes.
Server team claims "nothing changed," ha-ha. So did I do something or what? Please let me know! Thank you!
request object:
var request = {
url: 'xyz',
transport: 'long-polling',
reconnectInterval: 5000,
maxReconnectOnClose: 20,
enableXDR: true
};
Edit: the atmosphere server was changed from 2.1.3 (working) to 2.0.7 (not working) when the deploy occurred. When changed back, the 1 minute refresh behavior re-appeared. The problem is that 2.1.3 is not compatible with the server they are using, thus the down-grade.
Question: what is this feature called, is this the heartbeat or something else? Can someone tell me what change was made that would cause this. I've looked through the release notes and nothing jumped out at me.
Can someone please guide me as to what is the best way to have the time restriction timer in one of my online application written in Classic ASP with MsAccess database.
Simple process..Once the user shops, the system redirects the user to enter the billing & shipping information where-in this timer is shown and valid for 10 minutes.
Initially I captured the server side time and added 10 minutes using Classic ASP's DateAdd function "DATEADD("n",10, TIME())" and then used JavaScript to match the current time with the expiry time. But since site can be accessed from any part of the world, so taking server time is not helpful as Javascript matching is taking local PC time, so it will never match.
Secondly, when the user refreshes the page, the 10 minute timer will restart.
Appreciate your help. It can be through Javascript or Classic ASP.
In page1, do this
session("shopping_time") = now
In the subsequent pages
do this,
session("current_time" ) = now
time_elapsed = datediff("n",session("current_time" ),session("shopping_time"))
if ( time_elapsed > 10 ) then
//do something
end if
On my website I have a list of all online users, updated in real-time by node.js (I'm using now.js)
The problem is, when a user navigates my site, they of course disconnect for a couple of seconds when the new page is loading. Which means they disappear from the list for all other clients, to pop back in just seconds later.
Is there any way to set a timeout on the disconnect function, e.g. if user has not reconnected in 30 seconds, remove from the list otherwise don't?
Or if there is a better way to accomplish this? Can someone please point me in the right direction :)
EDIT:
Came up with a working solution, if anyone would like to know. On server side I have this function
nowjs.on('disconnect', function() {
everyone.now.clientDisconnected();
});
which whenever a user disconnects calls this function on the client
now.clientDisconnected = function() {
setTimeout(function() { now.serverUpdateUsers(); }, 20000);
}
So instead of updating the users right away, we wait 20 seconds. By then the user should have finished loading the new page, and no difference will show for all other clients.
The serverUpdateUsers(); is the serverside function that gathers all user data and pushes it out to all clients.
I'm not exactly sure if you can modify Socket.IO's settings with now.js (which uses Socket.IO), but if you could (not sure, never used now.js) you should set the heartbeat interval to be bigger:
https://github.com/LearnBoost/Socket.IO/wiki/Configuring-Socket.IO
heartbeat interval defaults to 20 seconds