I want to make an online DB based chat application. My problem is to detect changes in the DB, i.e. whenever a user sends a message to another user it should display to him. One approach is Ajax calls with setinterval but I want an instant solution. I do not want to keep the server busy with such Ajax calls.
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I am using Laravel Livewire, I currently have a form that captures a user's address information, then it needs to submit that to a 3rd party API (it's for billing information).
The issue that I am facing is that the UI doesnt update / livewire doesnt call render until after the entire method has run - which looks on the frontend like the UI is frozen / system isnt doing anything as the API is slow and takes a few seconds (15 - 20) to give a response.
I want to be able to trigger a browser event to display an alert saying the request is processing / show an alert banner on the page that it is processing before making the API request, process the API request, then display the results.
Currently I have identified the following ways to make this happen:
make the updates on the frontend, fire off an event with the data needed. Laravel event listener handles the API call, and emits a result event that the livewire component listens for, then the livewire component updates the page with the results.
make the updates on the frontend, dispatch a job to run in a queue worker, emit an event that the livewire component listens for, update the page with the results.
emit an event from the livewire component to itself, the livewire component then listens for that event and processes the API request, then updates the frontend with the results.
emit an event from the livewire component to itself to update the UI with processing info, while it still runs the API process in the original method call, and then updates the UI once the API gets a response
My thoughts are, what would be best practice here? All the above solutions require a different amount of work to get running, and solution 1 and 2 looks like complete overkill for such a simple process.
Does this come down to preference? Or is there actually a best practice way to do this in livewire?
And additionally, is there another way / simpler way to do this that I havnt mentioned above?
Your feedback is appreciated.
I would probably create a job and then return a response to the user. Then instigate Livewire polling that can check for the job being complete. If the API takes 15-20 seconds then polling once per second should be fine.
You might want to store the state in the database so that the job and the livewire component can communicate with each other. If you don't need to keep the data, using the cache to communicate between job and component would be a good alternative.
I'm developing a project with Symfony 3.4.
I would like to send a message to all the clients currently viewing a page when something happens. I evaluated both Server-Sent Events and Websockets, and I decided to go with the former, because the communication is unidirectional (only server to client).
For this purpose, I'm using this library: https://packagist.org/packages/tonyhhyip/sse
It seems to work, but I need to specifically send a message when something happens in the whole system. I tried with the Symfony event system (by creating a custom event), but events seem to be dispatched and captured only within the same session (i.e., the same logged user). In other words, if an action performed by a user triggers an event, it is not captured by other users and therefore a message is not sent to the browser via SSE.
Any suggestion?
Thank you
I have an app in backbone.js. The user can add items to the app which are added at the backend server and the collection is refreshed and the user sees the added data. How can I sync the app with any changes in the backend. Suppose if multiple users add the data at the same time each one should see the changes.
There are options like ajax polling where I can refresh the model after a certain time period but I hate to use it.
Can you suggest any event driven method where any change in the backend is reflected immediately in the frontend of my app.
You can add a kind of refresh event on your app, which will refresh every few minutes. Something like evernote desktop application does. In that event you would add collection sync event.
You can also use something like
collection.sync(method, collection, [options])
http://backbonejs.org/#Sync
This doesn't answer your question though, and I'm not sure how you would push changes from server to client.
I'm doing some updates for an intranet i created few years ago using ASP Classic. What i've been ask to do is to ALERT all users when news on intranet is added. Basically i need to check on database when news is added and than trigger an action to all intranet users saying you have New Message
I'have done a lot of research on this and i could't really find a good example for it.
Your help will be much appreciated.
Cheers
Vullnet
Basically to need to poll the server using AJAX and check for new messages.
I suppose you have a messages table with and ID that counts up. You need to track each user's last message pointer, and send this as part of your AJAX request ad a parameter. If the server's ID is higher thsn the user's then they have a new message.
Based on the AJAX response you then alert the user.
You need to make an ASP that responds to your AJAX call, Pass it a number and it responds with "OK" (not new) or "NEW".
IT works the same way, regardless of the server-side language. Use jQuery to perform your AJAX calls.
I'm wondering how it's implemented in Gmail, that every time you receive e-mail, the list of mails is automatically refreshed. It looks like the server is sending some kind of event to the browser, but how is it possible? Or maybe it’s simle: the browser ask the server for new messages every let’s say 2 seconds? But it would probably kill the performance…
Anyone have some ideas?
EDIT: OK, so if it's the simple answer, how do they manage performance? When I send an email from an other account to the gmail account the view is "refreshed" almost instantly. You were saying about a simple function that returns true / false, but it must have some logic (db connection or reads some files). How they manage it?
See also: How is GMail Chat able to make AJAX requests without client interaction?
Dont know exactly which technoloy Gmail uses, but the concept is to open a channel - using reverse AJAX, comet or sprocket based techniques.
Think of it as the client requesting the server for data, but the server does not return for one minute unless it has new mail. Using this technique, the client can almost show the results in a real time manner and it does not have to poll every 2 secs. Makes sense?
gmail is, in fact, polling the server for updates. Not as often as every two seconds, though. That would be madness. A bit of testing with Tamper Data makes it look like maybe every 20 seconds, though there seem to be multiple events going through that confuse it a bit.
Regarding your edit, I imagine they might have a last-activity timestamp on the account tracking in their database, with the client polling query retrieving that via Ajax and comparing with its last sync to determine whether it needs to do a full update.
You have right with simple answer. Google Mail checking new messages on server via AJAX.
It must be some kind of ajax listener that get informations every X seconds.
I already set something like that for one of my projects. What I was doing is calling a function that was returning true or false. True if the page needed to be refreshed, false otherwise. Then if you have an update, you do another call to get the actual update. This way you don't have to refresh everything every time... but it's still intense on the server if you have a lot of users.
In other words and like chaos said, it's polling the server.