Question 225471 in Javascript Question posted in
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Javascript – Return Promise on a callback function

I’d like to return a Promise on a spécific function that is not async.

The result is undefined when I call the function.

My code :

async function _callAccessControl(response, rpaReservation) {

  if (rpaResource.access_control_identifier && !accessControlExist) {
    return soap.createClientAsync('https://ipevia.com/public/files/onvif/credential.wsdl', {
      endpoint: 'https://ipevia.com/index.php?OnvifServer',
      forceSoap12Headers: true
    }).then((credentialClient) => {
      return credentialClient.CredentialService.CredentialPort.CreateCredential({
        Credential: {
          CredentialHolderReference: holderReference,
          CredentialIdentifier: {
            Type: {
              Name: 'pt:PIN',
              FormatType: 'SIMPLE_NUMBER16'
            },
            Value: rpaReservation.access_code
          },
          CredentialAccessProfile: {
            AccessProfileToken: rpaResource.access_control_identifier,
            ValidFrom: `${rpaReservationDateFormatted} ${rpaScheduleGrid.start_hour}:00`,
            ValidTo: `${rpaReservationDateFormatted} ${rpaScheduleGrid.end_hour}:00`
          }
        }
      }, function(err, result) {
        return rpaReservation.update({
          access_control_identifier: parseInt(result.Token, 10)
        }).then((updatedReservation) => {
          return updatedReservation;
        });
      }, { auth });
    });
  } else {
    return rpaReservation;
  }
}

_callAccessControl(response, rpaReservation).then((result) => {
  // result is undefined
})
Tags:

2

Answers


  1. 0

    Is this what you want?

    function myFunction() {
  return new Promise((resolve, reject) => {
    // Do something asynchronous here...
    setTimeout(() => {
      resolve('Success!');
    }, 1000);
  });
}

// Usage:
myFunction().then(result => {
  console.log(result); // Output: Success!
});

    I think resolve will resolve your problem. 🙂
    And reject will handle the error part.

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  2. 0

    You need to wrap credentialClient.CredentialService.CredentialPort.CreateCredential in a promise as shown below:

    function createCredentialWithPromise(credentialClient) {
  return new Promise((resolve, reject) => {
    credentialClient.CredentialService.CredentialPort.CreateCredential(
      {
        ...
      },
      function (err, result) {
        if (err) reject();
        else resolve(result);
      },
      { auth }
    );
  });
}

    and you can use it as shown below:

    function _callAccessControl(response, rpaReservation) {
  if (rpaResource.access_control_identifier && !accessControlExist) {
    return soap
      .createClientAsync(...)
      .then(credentialClient => {
        return createCredentialWithPromise(credentialClient);
      })
      .then(result => {
        return rpaReservation.update(...);
      })
  } else {
    return rpaReservation;
  }
}

    or, you can use the async-await syntax:

    async function _callAccessControl(response, rpaReservation) {
  if (rpaResource.access_control_identifier && !accessControlExist) {
    const credentialClient = await soap.createClientAsync(...);
    const result = await createCredentialWithPromise(credentialClient);
    return rpaReservation.update(...);
  } else {
    return rpaReservation;
  }
}
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