Sever Action Output Timing

Wappler General How To
1

I have a set of server actions running and created a custom module (with an output) that uploads a file to a new folder…

How do I ensure the file is there before moving to the next server action?

Currently putting a wait time of 10 seconds for example works but would like the code to run as soon as possible rather than an set time later.

response.data.pipe(fs.createWriteStream(destinationImagePath))
    .on('error', (err) => { return err, console.log(err) })
    .once('close', () => { return true, console.log('Success') });

if (response.err == true) {
    return ('Error');
} else {
    return ('Success');
};

Screen Shot 2022-02-25 at 12.08.20 PM
Screen Shot 2022-02-25 at 12.08.20 PM1876×1252 230 KB

2

You need to encapsulate such code (the response pipe thing only) inside a Promise:


You use await to wait till the promise is resolved
3

Great got it!

    // response.data.pipe(fs.createWriteStream(destinationImagePath))
//     .on('error', (err) => { return err, console.log(err) })
//     .once('close', () => { return true, console.log('Success') });

// if (response.err == true) {
//     return ('Error');
// } else {
//     return ('Success');
// };

return new Promise((resolve, reject) => {
    response.data.pipe(fs.createWriteStream(destinationImagePath))
        .on('error', reject)
        .once('close', () => resolve(destinationImagePath));
});
4

Isn’t it missing await?

return await new Promise((resolve, reject) => {
    response.data.pipe(fs.createWriteStream(destinationImagePath))
        .on('error', reject)
        .once('close', () => resolve(destinationImagePath));
});

Because, otherwise, it would return a Promise in pending state (it wouldn’t wait for the Promise to resolve). Unless Wappler does some magic behind the hood and waits for the Promise to resolve…

5

there is an await before the Promise…

not sure but from my short testing it seems to work. Might have to test a bit more.

6

I put it there :slightly_smiling_face: Unless you have another await somewhere else?

7

Hahhaa Nope I missed that, I thought that was a copy of my code.