I am building a real time application using AngularJS, NodeJS & Socket.IO. The application facilitates 3-4 large tables which are populted from a MongoDB database and after the initial load they only get updated.
Each table store almost 15-30Mb of data and it takes about 30 seconds to populate them using Socket.IO . Now, if a user navigates to a different page before all data is downloaded, the data required by the new page stays in the queue and is received after the table from the first page populates in full. Is there a way to pause or cancel the request when navigating to a different page?
Thanks in advance for your help.
--- Edit ---
To make the question more clear, here is the process that a user might follow:
The User opens /index and Grid_1 starts loading with Data from the server using Socket.IO. The data is coming in chunks of 50 records at the time. Grid_1 will eventualy get populated with 15.000 records and it will take 30 to download all the data.
After the user waits at /index for 10 secords, he decides to visit /mySecondPage where there is Grid_2 which simillar with Grid_1 populates from the database with 15.000 records which takes 30 seconds to download - again using Socket.IO. Since the user switched from /index to /mySecondPage before the data is populated in Grid_1, Grid_2 is not populated with data before Grid_1's data is fully downloaded. Hope that made it more clear?
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I'm basic web.api developer. I've almost 10000 records of data. As it is a huge data, basically takes more time to load. So, front end Dev. asked me to give an API such a way that he can pass the size of the records per scroll.
So, my question is Data Loading while scrolling should done by front end developer or web.api developer?. If it is web.api side how can i do that?
Please help me!!!
Thanks in advance.
You need to do it in both client's side and server side. You need to plan your table in the database that it will provide you options for paging so you can retrieve the data by a bulk of data. For example, select * from youTable whrere id between 1 and 50.
in angular, you have to use en event that will be fired every time when you scroll down and call to the web API service. You need to manage the data you already got and the data you will going to get and to send the indexes every time.
nice link in angular - https://sroze.github.io/ngInfiniteScroll/demo_basic.html
Basically front-end developer send a request for data to API with pagination parameter, for example :
for the first time request is like
http://example.com?page=1
here API should return for example first 1-20 data, for the second request the page number is incremented like http://example.com?page=2 so API return 21-40 data and so on.
It may possible front-end developer also pass the number of data required for each request, so you have to send the data in response as request.
I would be implementing a notification in my web app.
The technologies on which the app is built is Angularjs Apache PHP(For Api).
Our initial approach was to query the database every 10 seconds for any notification.
Is using socket.io beneficial in this scenario.?
It depends on the way you will implement it.
If you got only 1 or less new datasets in 10 seconds you will save capacity by sending a message via socket.io to the client to pull the new data.
If you got more than 1 new dataset in 10 seconds, the "pull every 10 seconds" will be better.
If you dont know how much new datasets will came up, you could the a mixed thing. Send a message to the client (via socket.io) to do the next pull. and then the client will pull timer-elapsion. if not, your timer will not pull the new data and will save network-traffic.
I have a C# Web API project on server side and on front-end I have ExtJS 4.2.1 (Javascript framework client).
There is a section in my app where I request to start a long running process (about 5 minutes) and I want to show the user the status of the process being executed.
Basically, the process will run a special calculation for every employee in the database (about 800), so I want to let the user know which Employee is being processed in that moment.
So I was thinking in two ways of doing this, and maybe I don't know if having both is ok.
Use SignalR to show the information of the process in Real Time.
Write to a database table all the process log (every employee that its being processed).
If I use the first approach, if the user close the browser he will loose all the information about the process and if he log into the app again he will only see the actual status.
If I use the second approach, if he log into the app again he could see all the information, and using maybe a timer on client side the data could be refreshed every 5 seconds.
Does anyone have implemented something like this? Any advice is appreciated.
You should use a combination of the two. When you have calculated a employee save the state to the database and publish the change on a service bus.
Let SignalR pick these messages up and forward them to the client. This way the user will see old state when he connects and new state then they arrive with SignalR. I have created a Event aggregator proxy that makes this very easy.
https://github.com/AndersMalmgren/SignalR.EventAggregatorProxy/wiki
Follow the wiki to set it up, here is a demo project
https://github.com/AndersMalmgren/SignalR.EventAggregatorProxy/tree/master/SignalR.EventAggregatorProxy.Demo.MVC4
Live demo
http://malmgrens.org/Signalr/
I am creating a webpage to show the listing from my database table,
suppose my database table is updating in every 10 second from my php cron , then i want to sync my backbone model/collection whenever my database table get update from my php cron.
Example:- i have table stock_exchange in which i am storing the stocks rate for various companies, and my cronjob update the stocks rate in every 10 second, To show this on UI i am creating the backbone application but my problem is that whenever my table stock_exchange updated i want to sync my backbone model/collection.
Please help,
Thanks in advance
You can either poll the server by calling stockModel.fetch() every 10 seconds in the browser (via setInterval perhaps), or you can use something like web sockets (via socket.io perhaps) to allow the server to push the latest data to the browser, which you can then do stockModel.set(dataFromServer);. Try something and post some code as stack overflow is intended for specific problems not tutorials.
i have a scenario where i have to load data from SQL server when i start running a web service. Later i have to use this data for my application, instead of accessing it every time from Database. In addition to this this data should be refreshed every one hour without affecting the website operation on the back end.If any of you has came across such scenario please let me know the solution. By the way i am using asp.net web services, SQL server database, and DNN for my front end.Thanks in advance.
In Global Asax,Application start event you can load all your data in the Dataset.
And by using Sql Cache dependency, You can refresh the data for each hour.But loading the
Entire data is not advisable.By making so you memory will be full.There will
be Performance degrade.
http://www.codeproject.com/Articles/14976/ASP-NET-Caching-Dependencies
Pre-loading all of your data is not a good practice because the database loses its purpose then. It’s probably ok for some data that is very rarely updated but needed very frequently but most definitely not for all the data you have in database.
As for the loading of data you can use app start event as others have already suggested.
Regarding caching – use Application object to make this data available to all parts of application and add a proprety to it that will keep the time of the last update. Then just create separate service that will check the last update time every X minutes and refresh the data when the time comes.