Remote Action - wait for response

Question

I'm uploading files in vf page form (site force.com) using remote action.

I want to wait for the remote action will finish its method, and only then proceed - means - do it synchronously, because I need all the files will be loaded before submitting the form.

 Visualforce.remoting.Manager.invokeAction(
                    '{!$RemoteAction.PaymentFormController.dfqwerFile}',
                    var1,var2,var3,var4,var5,
                    function(result, event){
                        if (event.status) {
                               console.log('status',event.status);
                        } else if (event.type === 'exception') {
                               console.log('failed');

                        } else {
                            console.log('Succes');

                        }
                    },
                    {escape: true}
                );

Any way to achieve it?

Thanks!

Answer 1

Remote functions are asynchronous by nature. There's no such thing as synchronous calls in JavaScript these days, because they cause the page to become unresponsive while they're processed. However, you can simulate this in your code using async await:

async function remoteAction(var1, var2, var3, var4, var5) {
  return new Promise((resolve, reject) => {
    Visualforce.remoting.Manager.invokeAction(
      "{!$RemoteAction.PaymentFormController.dfqwerFile}",
      var1,
      var2,
      var3,
      var4,
      var5,
      (result, event) => {
        event.status ? resolve(result) : reject(event.message);
      },
      { escape: true }
    );
  });
}
async function onclick(event) {
  try {
    // Get the values for the variables, then...
    await remoteAction(var1,var2,var3,var4,var5);
    // Next line will execute only when remote action finishes.
    doMoreStuffHere();
  } catch(e) {
    // handle the error here
  }
}

Note that Internet Explorer does not support this syntax, so if you use it, you'll get a script error instead of the desired behavior.