multer-derive

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Provides a FromMultipart derive for construct types from multer::Multipart.

Usage

```rs use multer_derive::{FormFile, FromMultipart, Multipart, MultipartForm};

[derive(FormMultipart)]

struct Person { name: String, email: String, age: u8, married: bool, photo: FormFile }

const FORMDATA : &str = "--boundarystring\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\nJohn Smith\r\n--boundarystring\r\nContent-Disposition: form-data; name=\"email\"\r\n\r\njohn@example.com\r\n--boundarystring\r\nContent-Disposition: form-data; name=\"age\"\r\n\r\n25\r\n--boundarystring\r\nContent-Disposition: form-data; name=\"married\"\r\n\r\ntrue\r\n--boundarystring\r\nContent-Disposition: form-data; name=\"photo\"; filename=\"example.jpg\"\r\nContent-Type: image/jpeg\r\n\r\n[Binary data]\r\n--boundary_string--\r\n";

let reader = FORMDATA.asbytes(); let multipart = Multipart::withreader(reader, "boundarystring");

let form = MultipartForm::withmultipart(multipart).await.unwrap(); let person = Person::frommultipart(form).unwrap();

asserteq!(person.name, "John Smith"); asserteq!(person.email, "john@example.com"); asserteq!(person.age, 25); asserteq!(person.married, true);

let str = String::fromutf8(person.photo.bytes().tovec()).unwrap(); assert_eq!(str, "[Binary data]"); ```

Attributes

multer-derive also support the next attributes to decorate your fields:

• To rename the target you can use #[multer(rename = "new_field_name")]
  • This will make multer to parse the field using the given name.

Example:

```rs use multer_derive::FromMultipart;

[derive(FromMultipart)]

struct MyStruct { #[multer(rename = "active")] is_active: bool } ```

• To parse using a function you can use #[multer(with = "path::to::function")]

  • For this you should provide a function with the signature:

  rs fn from_multipart(multipart: &MultipartForm, ctx: FormContext<'_>) -> Result<YourType, Error> { todo!() }

Example:

```rs use multer_derive::{FromMultipart, MultipartForm, FormContext, Error};

[derive(FromMultipart)]

struct MyStruct { #[multer(with = "textfrommultipart")] name: Text }

struct Text(String);

fn textfrommultipart( multipart: &MultipartForm, ctx: FormContext<'>, ) -> Result { // This is safe, the field_name is always passed let fieldname = ctx.field_name.unwrap();

// We search the field in the source multipart
let field = multipart
    .get_by_name(field_name)
    .ok_or(Error::new(format!(
        "`{field_name}` form field was not found"
    )))?;

// Parse the value using `String`
let s = String::from_field(field)?;
Ok(Text(s))

} ```