Can I get a return value outside of Promise?

[Dingbing Liw]

Hi, all.

I am refactoring my mojolicious app.

Is there any way to use promise and keep the same return value?

For example:

My original  method:

sub some_method {

  my $a = block_function_a();

  my $b = block_function_b();

  my $c = block_function_c();  ### for example many Mojo::Pg search

  return $a+$b+$c;

}

Now I change block_function_c to  an unblocked promise.

sub some_method {

  my $a = block_function_a();

  my $b = block_function_b();

  return promise_mojo_db_search->then(sub($c){ 

       $a+$b+c;

   }

);

}

I have to change many relative code after the return value change.

It is very annoying.

Is there any way to return the same value with promise.

[Vincent Tondellier]

Hi,

On 2021-08-04, 11:30:43 CEST Dingbing Liw wrote:
> I am refactoring my mojolicious app.
> Is there any way to use promise and keep the same return value?

You can use async/await for this.

See https://metacpan.org/dist/Mojolicious/view/lib/Mojolicious/Guides/Cookbook.pod#async/await

Your example would be:

sub some_method {
my $a = block_function_a();
my $b = block_function_b();

my $c = await nonblock_function_c();
return $a+$b+$c;
}

where nonblock_function_c can either return a promise or be an async function (see doc)

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