I am doing a real time app, and in one part of the application, some data is posted to the server when an event is triggered, this is then updated to the db. The problem is each browser connection instance is posting the same data, resulting in multiple db updates from the instances. I can't seem to see a way of figuring this out. Kindly assist.
I fixed it by sending post results from a single client who matched some criteria, and now it works fine.
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I'm sending data from my backend every 10 seconds and I wanted to display that data in reactjs. I've searched on the net to use socket.io to display real-time data. Is there a better way to use it?
If you're dead set on updating your data every 10 seconds, it would make more sense to make a request from the client to the server, as HTTP requests can only be opened from client to server. By using HTTP requests, you won't need to use socket.io, but socket.io is an easy alternative if you need much faster requests.
Depending on how you are generating the data being sent from your backend, specifically if you are using a database, there is most likely a way to subscribe to changes in the database. This would actually update the data in realtime, without a 10 second delay.
If you want a more detailed answer, you'll have to provide more detail regarding your question: what data are you sending? where is it coming from or how are you generating it?
I'm working on an autodialer feature, in which an agent will get a call when I trigger the button from the frontend (using react js language), and then automatically all the leads in the agent assigned portal will get back-to-back calls from agent number. However, because this process is automatic, the agent won't know who the agent has called, so I want to establish a real-time connection so that I can show a popup on the frontend that contains information about the lead who was called.
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'm looking for a way (and not even sure if this is possible) to update an Angular expression on my HTML page when data is sent to an API.
For example, say I have $scope.message on my .html page. Is there a way I can send a message to an API (e.g. http://...?message=foo) and have my page update with the message sent?
Also, I need the $scope.message to be updated in an Angular Service so it is available to multiple pages within my website.
I am wanting this to be a live update, but if not, I am happy with some code executing on a timer or something similar.
Any suggestions appreciated.
UPDATE
I'm guessing it may not be possible, but just in case I haven't explained it correctly, I'll try and simplify it.
I can only find information about using AngularJS to send GET commands OUT to a URL and receive data back. I need to send a JSON string TO my Angular site to update a variable. So basically as a field updates in my database, I want another server application to send an alert to my Angular site to update the status of this value live. I don't really want to run a constant check of the database if I don't have to.
I am open to any other suggestions on how to achieve this.
if you don't care about old school browsers, you can try using WebSocket, it is similar to a TCP socket, which allows you to push from server to client. I would create a service that manages the websocket connection, and update scope when receiving message. Hope this help. More info here: https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API
I am using ratchet websockets to connect to a WAMP Autobahn front-end.
Everything works perfectly however when I change the topic code, the responses do not change!
i am running this in docker, when I restart the containers the updates responses get sent but then if I change this again nothing happens!
Your questions doesn't have many details but I think what is happening is your are running the PHP WebSocket server. Then changing the PHP code and expect the server to automatically update. That isn't how it works, you have to restart the websocket for code changes to take effect.
If you want to have a dynamic response without restarting the socket I suggest using a database or other data store that you can dynamically change and PHP can fetch from
I am using sessions saved in the database. Works well. Lot of data relating to pagination, browsing history etc is stored perfectly within the database.
However, I notice that data sent to a controller using Ajax is not being stored successfully.
If I debug the session within the controller called by ajax, right after I have set the session vars, I see the values appear to be stored correctly in the session, but on subsequent requests, it transpires that the session vars have NOT been saved.
I have done some testing and have found that the problem disappears if I change back to using "php" for the session instead of "database".
I have eliminated pretty much everything from the mix - and it boils down to Cake not saving session data that is sent by ajax. Again, simply switching back to using "php" for sessions, and everything works perfectly.
I wonder if anyone has experienced anything similar?
CakePHP 2.4
Many thanks.
Well, in case anyone is interested, it turns out that the issue I was having was not strictly related to storing sessions in the database.
My application was making 2 ajax calls at the same time, both attempting to update the session. This was a bug / error on my part, and was causing other session-related issues too, such as returning 403 error status.
I removed the offending bug and all is now well.