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use std::borrow::Cow;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddrV4, SocketAddrV6, SocketAddr};
use std::num::{
NonZeroIsize, NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128,
NonZeroUsize, NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU128,
};
use time::{Date, Time, PrimitiveDateTime};
use time::{macros::format_description, format_description::FormatItem};
use crate::data::Capped;
use crate::http::uncased::AsUncased;
use crate::form::prelude::*;
/// Implied form guard ([`FromForm`]) for parsing a single form field.
///
/// Types that implement `FromFormField` automatically implement [`FromForm`]
/// via a blanket implementation. As such, all `FromFormField` types are form
/// guards and can appear as the type of values in derived `FromForm` struct
/// fields:
///
/// ```rust
/// # use rocket::form::FromForm;
/// #[derive(FromForm)]
/// struct Person<'r> {
/// name: &'r str,
/// age: u16
/// }
/// ```
///
/// # Deriving
///
/// `FromFormField` can be derived for C-like enums, where the generated
/// implementation case-insensitively parses fields with values equal to the
/// name of the variant or the value in `field(value = "...")`.
///
/// ```rust
/// # use rocket::form::FromFormField;
/// /// Fields with value `"simple"` parse as `Kind::Simple`. Fields with value
/// /// `"fancy"` parse as `Kind::SoFancy`.
/// #[derive(FromFormField)]
/// enum Kind {
/// Simple,
/// #[field(value = "fancy")]
/// SoFancy,
/// }
/// ```
///
/// # Provided Implementations
///
/// See [`FromForm`](crate::form::FromForm#provided-implementations) for a list
/// of all form guards, including those implemented via `FromFormField`.
///
/// # Implementing
///
/// Implementing `FromFormField` requires implementing one or both of
/// `from_value` or `from_data`, depending on whether the type can be parsed
/// from a value field (text) and/or streaming binary data. Typically, a value
/// can be parsed from either, either directly or by using request-local cache
/// as an intermediary, and parsing from both should be preferred when sensible.
///
/// `FromFormField` is an async trait, so implementations must be decorated with
/// an attribute of `#[rocket::async_trait]`:
///
/// ```rust
/// # #[macro_use] extern crate rocket;
/// # struct MyType;
/// use rocket::form::{self, FromFormField, DataField, ValueField};
///
/// #[rocket::async_trait]
/// impl<'r> FromFormField<'r> for MyType {
/// fn from_value(field: ValueField<'r>) -> form::Result<'r, Self> {
/// todo!("parse from a value or use default impl")
/// }
///
/// async fn from_data(field: DataField<'r, '_>) -> form::Result<'r, Self> {
/// todo!("parse from a value or use default impl")
/// }
/// }
/// ```
///
/// ## Example
///
/// The following example parses a custom `Person` type with the format
/// `$name:$data`, where `$name` is expected to be string and `data` is expected
/// to be any slice of bytes.
///
/// ```rust
/// # use rocket::post;
/// use rocket::data::ToByteUnit;
/// use rocket::form::{self, FromFormField, DataField, ValueField};
///
/// use memchr::memchr;
///
/// struct Person<'r> {
/// name: &'r str,
/// data: &'r [u8]
/// }
///
/// #[rocket::async_trait]
/// impl<'r> FromFormField<'r> for Person<'r> {
/// fn from_value(field: ValueField<'r>) -> form::Result<'r, Self> {
/// match field.value.find(':') {
/// Some(i) => Ok(Person {
/// name: &field.value[..i],
/// data: field.value[(i + 1)..].as_bytes()
/// }),
/// None => Err(form::Error::validation("does not contain ':'"))?
/// }
/// }
///
/// async fn from_data(field: DataField<'r, '_>) -> form::Result<'r, Self> {
/// // Retrieve the configured data limit or use `256KiB` as default.
/// let limit = field.request.limits()
/// .get("person")
/// .unwrap_or(256.kibibytes());
///
/// // Read the capped data stream, returning a limit error as needed.
/// let bytes = field.data.open(limit).into_bytes().await?;
/// if !bytes.is_complete() {
/// Err((None, Some(limit)))?;
/// }
///
/// // Store the bytes in request-local cache and split at ':'.
/// let bytes = bytes.into_inner();
/// let bytes = rocket::request::local_cache!(field.request, bytes);
/// let (raw_name, data) = match memchr(b':', bytes) {
/// Some(i) => (&bytes[..i], &bytes[(i + 1)..]),
/// None => Err(form::Error::validation("does not contain ':'"))?
/// };
///
/// // Try to parse the name as UTF-8 or return an error if it fails.
/// let name = std::str::from_utf8(raw_name)?;
/// Ok(Person { name, data })
/// }
/// }
///
/// use rocket::form::{Form, FromForm};
///
/// // The type can be used directly, if only one field is expected...
/// #[post("/person", data = "<person>")]
/// fn person(person: Form<Person<'_>>) { /* ... */ }
///
/// // ...or as a named field in another form guard...
/// #[derive(FromForm)]
/// struct NewPerson<'r> {
/// person: Person<'r>
/// }
///
/// #[post("/person", data = "<person>")]
/// fn new_person(person: Form<NewPerson<'_>>) { /* ... */ }
/// ```
// NOTE: Ideally, we would have two traits instead one with two fallible
// methods: `FromFormValue` and `FromFormData`. This would be especially nice
// for use with query values, where `FromFormData` would make no sense.
//
// However, blanket implementations of `FromForm` for these traits would result
// in duplicate implementations of `FromForm`; we need specialization to resolve
// this concern. Thus, for now, we keep this as one trait.
#[crate::async_trait]
pub trait FromFormField<'v>: Send + Sized {
/// Parse a value of `T` from a form value field.
///
/// The default implementation returns an error of
/// [`ValueField::unexpected()`].
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
Err(field.unexpected())?
}
/// Parse a value of `T` from a form data field.
///
/// The default implementation returns an error of
/// [`DataField::unexpected()`].
async fn from_data(field: DataField<'v, '_>) -> Result<'v, Self> {
Err(field.unexpected())?
}
/// Returns a default value, if any exists, to be used during lenient
/// parsing when the form field is missing.
///
/// A return value of `None` means that field is required to exist and parse
/// successfully, always. A return value of `Some(default)` means that
/// `default` should be used when a field is missing.
///
/// The default implementation returns `None`.
fn default() -> Option<Self> { None }
}
#[doc(hidden)]
pub struct FromFieldContext<'v, T: FromFormField<'v>> {
field_name: Option<NameView<'v>>,
field_value: Option<&'v str>,
opts: Options,
value: Option<Result<'v, T>>,
pushes: usize
}
impl<'v, T: FromFormField<'v>> FromFieldContext<'v, T> {
fn should_push(&mut self) -> bool {
self.pushes += 1;
self.value.is_none()
}
fn push(&mut self, name: NameView<'v>, result: Result<'v, T>) {
fn is_unexpected(e: &Errors<'_>) -> bool {
matches!(e.last().map(|e| &e.kind), Some(ErrorKind::Unexpected))
}
self.field_name = Some(name);
match result {
Err(e) if !self.opts.strict && is_unexpected(&e) => { /* ok */ },
result => self.value = Some(result),
}
}
}
#[crate::async_trait]
impl<'v, T: FromFormField<'v>> FromForm<'v> for T {
type Context = FromFieldContext<'v, T>;
fn init(opts: Options) -> Self::Context {
FromFieldContext {
opts,
field_name: None,
field_value: None,
value: None,
pushes: 0,
}
}
fn push_value(ctxt: &mut Self::Context, field: ValueField<'v>) {
if ctxt.should_push() {
ctxt.field_value = Some(field.value);
ctxt.push(field.name, Self::from_value(field))
}
}
async fn push_data(ctxt: &mut FromFieldContext<'v, T>, field: DataField<'v, '_>) {
if ctxt.should_push() {
ctxt.push(field.name, Self::from_data(field).await);
}
}
fn finalize(ctxt: Self::Context) -> Result<'v, Self> {
let mut errors = match ctxt.value {
Some(Ok(val)) if !ctxt.opts.strict || ctxt.pushes <= 1 => return Ok(val),
Some(Ok(_)) => Errors::from(ErrorKind::Duplicate),
Some(Err(errors)) => errors,
None if !ctxt.opts.strict => match <T as FromFormField>::default() {
Some(default) => return Ok(default),
None => Errors::from(ErrorKind::Missing)
},
None => Errors::from(ErrorKind::Missing),
};
if let Some(name) = ctxt.field_name {
errors.set_name(name);
}
if let Some(value) = ctxt.field_value {
errors.set_value(value);
}
Err(errors)
}
}
#[crate::async_trait]
impl<'v> FromFormField<'v> for Capped<&'v str> {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
Ok(Capped::from(field.value))
}
async fn from_data(f: DataField<'v, '_>) -> Result<'v, Self> {
use crate::data::{Capped, Outcome, FromData};
match <Capped<&'v str> as FromData>::from_data(f.request, f.data).await {
Outcome::Success(p) => Ok(p),
Outcome::Failure((_, e)) => Err(e)?,
Outcome::Forward(..) => {
Err(Error::from(ErrorKind::Unexpected).with_entity(Entity::DataField))?
}
}
}
}
impl_strict_from_form_field_from_capped!(&'v str);
#[crate::async_trait]
impl<'v> FromFormField<'v> for Capped<String> {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
Ok(Capped::from(field.value.to_string()))
}
async fn from_data(f: DataField<'v, '_>) -> Result<'v, Self> {
use crate::data::{Capped, Outcome, FromData};
match <Capped<String> as FromData>::from_data(f.request, f.data).await {
Outcome::Success(p) => Ok(p),
Outcome::Failure((_, e)) => Err(e)?,
Outcome::Forward(..) => {
Err(Error::from(ErrorKind::Unexpected).with_entity(Entity::DataField))?
}
}
}
}
impl_strict_from_form_field_from_capped!(String);
impl<'v> FromFormField<'v> for bool {
fn default() -> Option<Self> {
Some(false)
}
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
match field.value.as_uncased() {
v if v == "off" || v == "no" || v == "false" => Ok(false),
v if v.is_empty() || v == "on" || v == "yes" || v == "true" => Ok(true),
// force a `ParseBoolError`
_ => Ok("".parse()?),
}
}
}
#[crate::async_trait]
impl<'v> FromFormField<'v> for Capped<&'v [u8]> {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
Ok(Capped::from(field.value.as_bytes()))
}
async fn from_data(f: DataField<'v, '_>) -> Result<'v, Self> {
use crate::data::{Capped, Outcome, FromData};
match <Capped<&'v [u8]> as FromData>::from_data(f.request, f.data).await {
Outcome::Success(p) => Ok(p),
Outcome::Failure((_, e)) => Err(e)?,
Outcome::Forward(..) => {
Err(Error::from(ErrorKind::Unexpected).with_entity(Entity::DataField))?
}
}
}
}
impl_strict_from_form_field_from_capped!(&'v [u8]);
#[crate::async_trait]
impl<'v> FromFormField<'v> for Capped<Cow<'v, str>> {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
let capped = <Capped<&'v str>>::from_value(field)?;
Ok(capped.map(|s| s.into()))
}
async fn from_data(field: DataField<'v, '_>) -> Result<'v, Self> {
let capped = <Capped<&'v str>>::from_data(field).await?;
Ok(capped.map(|s| s.into()))
}
}
impl_strict_from_form_field_from_capped!(Cow<'v, str>);
macro_rules! impl_with_parse {
($($T:ident),+ $(,)?) => ($(
impl<'v> FromFormField<'v> for $T {
#[inline(always)]
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
Ok(field.value.parse()?)
}
}
)+)
}
impl_with_parse!(
f32, f64,
isize, i8, i16, i32, i64, i128,
usize, u8, u16, u32, u64, u128,
NonZeroIsize, NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128,
NonZeroUsize, NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU128,
Ipv4Addr, IpAddr, Ipv6Addr, SocketAddrV4, SocketAddrV6, SocketAddr
);
//
// Keep formats in sync with 'FromFormField' impls.
static DATE_FMT: &[FormatItem<'_>] = format_description!("[year padding:none]-[month]-[day]");
static TIME_FMT1: &[FormatItem<'_>] = format_description!("[hour padding:none]:[minute]:[second]");
static TIME_FMT2: &[FormatItem<'_>] = format_description!("[hour padding:none]:[minute]");
static DATE_TIME_FMT1: &[FormatItem<'_>] =
format_description!("[year padding:none]-[month]-[day]T[hour padding:none]:[minute]:[second]");
static DATE_TIME_FMT2: &[FormatItem<'_>] =
format_description!("[year padding:none]-[month]-[day]T[hour padding:none]:[minute]");
impl<'v> FromFormField<'v> for Date {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
let date = Self::parse(field.value, &DATE_FMT)
.map_err(|e| Box::new(e) as Box<dyn std::error::Error + Send>)?;
Ok(date)
}
}
impl<'v> FromFormField<'v> for Time {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
let time = Self::parse(field.value, &TIME_FMT1)
.or_else(|_| Self::parse(field.value, &TIME_FMT2))
.map_err(|e| Box::new(e) as Box<dyn std::error::Error + Send>)?;
Ok(time)
}
}
impl<'v> FromFormField<'v> for PrimitiveDateTime {
fn from_value(field: ValueField<'v>) -> Result<'v, Self> {
let dt = Self::parse(field.value, &DATE_TIME_FMT1)
.or_else(|_| Self::parse(field.value, &DATE_TIME_FMT2))
.map_err(|e| Box::new(e) as Box<dyn std::error::Error + Send>)?;
Ok(dt)
}
}