question: How can I convert some optional parameters defined in the model without excluding the attributes not defined in the model?

[Chen-913]

I was trying to...

I hope that when some parameters of the Model are optional, I can automatically remove some parameters that are not passed in, instead of changing its value to undefined.

As the example in the document:

import { Expose, plainToClass } from 'class-transformer';

// Assume that these fields are optional
class User {
  @Expose() id?: number;
  @Expose() firstName?: string;
  @Expose() lastName?: string;
}

const fromPlainUser = {
  unkownProp: 'hello there',
  firstName: 'Umed',
  lastName: 'Khudoiberdiev',
};

console.log(plainToInstance(User, fromPlainUser, { excludeExtraneousValues: true }));

// User {
//   id: undefined,
//   firstName: 'Umed',
//   lastName: 'Khudoiberdiev'
// }

The problem:

In the case of no id transfer, it is converted to undefined by default, which I don't want to do. The effect I want is that if I don't transfer the id field, the converted object will not have the id field.

I know that fields with undefined can be removed by some other methods.
for example:

console.log(JSON.parse(JSON.strigify(transformObj)));
// User {
//   firstName: 'Umed',
//   lastName: 'Khudoiberdiev'
// }

I want to ask whether this tool provides such functions or options to call to achieve this effect. I can't find it in the document.

[diffy0712]

Hello @Chen-913,

you can try the exposeUnsetFields: false option like: console.log(plainToInstance(User, fromPlainUser, { excludeExtraneousValues: true, exposeUnsetFields: false}));

[reedoso]

@diffy0712 Hello there. This is not working. All fields are undefined=(

[Chen-913]

Are there any plans to fix this issue?🧐