Filtering properties with PartialClassToPlain

Hi Marc,

Thanks for this awesome lib! I have a feature request, I Thought I could use partialPlainToClass with @f.exclude but doesn’t really cover my need.

I would like to filter all nested params based on some filter name. Example:

class Book {
  @f.filter('myFilter')
  title:string

  @f
  isbn: string
}

class Reader {
  @f.filter(['myFilter', 'myAgeFilter'])
  name:string

  @f.filter(['myAgeFilter'])
  age: int
  
  @f.array(Book).filter("myFilter")
  books: Book[]
}

const reader:Reader =  plainToClass(Reader, {
  name: 'rafael',
  age: 34,
  books: [ 
     { title: "Lean Startup", isbn: "xxxx-yyyy-zzzz" },
     { title: "Traction", isbn: "zzzz-xxxx-yyyy" },
  ]
});

I need to convert this reader back into a plain object, but only containing some of its properties (and nested properties), based on the filter name. I would expect something like this:

const filteredReader = partialClassToPlain(Reader, reader, 'myFilter');
{ 
  name: 'rafael',
  books: [ 
    {title: 'Lean Startup'}, 
    {title: 'Traction'}
  ] 
}
const filteredReader2 = partialClassToPlain(Reader, reader, 'myAgeFilter');
{ 
  name: 'rafael',
  age: 34
}

There is a way to achieve this with the current api? If there’s not, does this make sense to you?

I Want to use this to send json through an API, only sending the pertinent fields to each URL.

[marcj]

@rafaferry unfortunately, not that straightforward since i in partial can be a deep path, e.g. user.settings.color, so that loop is not the right place. It needs to be in JitPropertyConverter.convert() where we have the PropertySchema. PropertySchema needs to be extended to hold the group information plus the @f decorator needs to be updated to support setting a group name. I’m going to implement it once I find the time.

[marcj]

Yeah I had such a group mechanism already on my list but didn’t find the time yet. Totally makes sense! Indeed @f.exclude is on compile level, what you need is on runtime level. I’d implement it as you explained, except that to rename filter to group, and maybe change the third argument of partial*() a bit (into a option object).