Detecting changes on database table column status-CodePudding

I am having a project in Laravel. In database I have a status column, which shows if exam is started or not. I had an idea in the waiting room checking every single second if the status was changed or not, if changed to 1, when the exam starts, but I am so new to Laravel and everything else, that I even don't get the main idea how I could do this, I don't ask for any code, just for the lead, to move on. yeah, hope someones gets me. Thanks if someone answers me.

CodePudding user response：

Check about laravel cron jobs. You will need a class implementing ShouldQueue interface and using Dispatchable, InteractsWithQueue, Queueable, SerializesModels; With regards to the storage of the jobs i do recommend Redis or SQS. In order to keep monitoring the queue in production think about installing supervisor. Further information here: Queues

CodePudding user response：

Your plan can work, it is called polling.

Basically, you will want to call

setInterval(function() {
    //your code here
}, 1000);

setInterval is a function that receives two parameter. The first is a callback function, that will periodically be executed and the second is the length of the period in milliseconds (1000 milliseconds is a second).

Now, you will need to implement your callback function (Javascript, of course) to send an AJAX request to a Laravel action. You will need to look into XMLHttpRequest and its usages, or you can use some libraries to simplify your task, like jQuery or Axios.

On Laravel's side you will need to implement an action and a Route for it. (read this: https://appdividend.com/2022/01/22/laravel-ajax/)

Your Laravel will need to load data from your database, you can use Eloquent for this purpose or raw queries and then respond the POST request with the result.

Now, in your Javascript at the AJAX request's code you will need to have a callback function (yes, a callback inside a callback) which will handle the response and the the changes.