Enum rocket::request::FormItems

pub enum FormItems<'f> {
    // some variants omitted
}

Iterator over the key/value pairs of a given HTTP form string.

use rocket::request::{FormItems, FromFormValue};

// Using the `key_value_decoded` method of `FormItem`.
let form_string = "greeting=Hello%2C+Mark%21&username=jake%2Fother";
for (key, value) in FormItems::from(form_string).map(|i| i.key_value_decoded()) {
    match &*key {
        "greeting" => assert_eq!(value, "Hello, Mark!".to_string()),
        "username" => assert_eq!(value, "jake/other".to_string()),
        _ => unreachable!()
    }
}

// Accessing the fields of `FormItem` directly, including `raw`.
for item in FormItems::from(form_string) {
    match item.key.as_str() {
        "greeting" => {
            assert_eq!(item.raw, "greeting=Hello%2C+Mark%21");
            assert_eq!(item.value, "Hello%2C+Mark%21");
            assert_eq!(item.value.url_decode(), Ok("Hello, Mark!".into()));
        }
        "username" => {
            assert_eq!(item.raw, "username=jake%2Fother");
            assert_eq!(item.value, "jake%2Fother");
            assert_eq!(item.value.url_decode(), Ok("jake/other".into()));
        }
        _ => unreachable!()
    }
}

Form Items via. FormItem

This iterator returns values of the type FormItem. To access the associated key/value pairs of the form item, either directly access them via the key and value fields, use the FormItem::key_value() method to get a tuple of the raw (key, value), or use the key_value_decoded() method to get a tuple of the decoded (key, value).

Completion

The iterator keeps track of whether the form string was parsed to completion to determine if the form string was malformed. The iterator can be queried for completion via the completed() method, which returns true if the iterator parsed the entire string that was passed to it. The iterator can also attempt to parse any remaining contents via exhaust(); this method returns true if exhaustion succeeded.

This iterator guarantees that all valid form strings are parsed to completion. The iterator attempts to be lenient. In particular, it allows the following oddball behavior:

• Trailing and consecutive & characters are allowed.
• Empty keys and/or values are allowed.

Additionally, the iterator skips items with both an empty key and an empty value: at least one of the two must be non-empty to be returned from this iterator.

Examples

FormItems can be used directly as an iterator:

use rocket::request::FormItems;

// prints "greeting = hello", "username = jake", and "done = "
let form_string = "greeting=hello&username=jake&done";
for (key, value) in FormItems::from(form_string).map(|item| item.key_value()) {
    println!("{} = {}", key, value);
}

This is the same example as above, but the iterator is used explicitly.

use rocket::request::FormItems;

let form_string = "greeting=hello&username=jake&done";
let mut items = FormItems::from(form_string);

let next = items.next().unwrap();
assert_eq!(next.key, "greeting");
assert_eq!(next.value, "hello");

let next = items.next().unwrap();
assert_eq!(next.key, "username");
assert_eq!(next.value, "jake");

let next = items.next().unwrap();
assert_eq!(next.key, "done");
assert_eq!(next.value, "");

assert_eq!(items.next(), None);
assert!(items.completed());

Methods

impl<'f> FormItems<'f>

pub fn completed(&self) -> bool

Returns true if the form string was parsed to completion. Returns false otherwise. All valid form strings will parse to completion, while invalid form strings will not.

Example

A valid form string parses to completion:

use rocket::request::FormItems;

let mut items = FormItems::from("a=b&c=d");
let key_values: Vec<_> = items.by_ref().collect();

assert_eq!(key_values.len(), 2);
assert_eq!(items.completed(), true);

In invalid form string does not parse to completion:

use rocket::request::FormItems;

let mut items = FormItems::from("a=b&==d");
let key_values: Vec<_> = items.by_ref().collect();

assert_eq!(key_values.len(), 1);
assert_eq!(items.completed(), false);

pub fn exhaust(&mut self) -> bool

Parses all remaining key/value pairs and returns true if parsing ran to completion. All valid form strings will parse to completion, while invalid form strings will not.

Example

A valid form string can be exhausted:

use rocket::request::FormItems;

let mut items = FormItems::from("a=b&c=d");

assert!(items.next().is_some());
assert_eq!(items.completed(), false);
assert_eq!(items.exhaust(), true);
assert_eq!(items.completed(), true);

An invalid form string cannot be exhausted:

use rocket::request::FormItems;

let mut items = FormItems::from("a=b&=d=");

assert!(items.next().is_some());
assert_eq!(items.completed(), false);
assert_eq!(items.exhaust(), false);
assert_eq!(items.completed(), false);
assert!(items.next().is_none());

Trait Implementations

impl<'f> Debug for FormItems<'f>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'f> From<&'f [FormItem<'f>]> for FormItems<'f>

Important traits for FormItems<'f>

impl<'f> Iterator for FormItems<'f> type Item = FormItem<'f>;

fn from(items: &'f [FormItem<'f>]) -> FormItems<'f>

Performs the conversion.

impl<'f> From<&'f RawStr> for FormItems<'f>

Important traits for FormItems<'f>

impl<'f> Iterator for FormItems<'f> type Item = FormItem<'f>;

fn from(string: &'f RawStr) -> FormItems<'f>

Performs the conversion.

impl<'f> From<&'f str> for FormItems<'f>

Important traits for FormItems<'f>

impl<'f> Iterator for FormItems<'f> type Item = FormItem<'f>;

fn from(string: &'f str) -> FormItems<'f>

Performs the conversion.

impl<'f> Iterator for FormItems<'f>

type Item = FormItem<'f>

The type of the elements being iterated over.

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn count(self) -> usize

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>

Consumes the iterator, returning the last element.

fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the nth element of the iterator.

fn step_by(self, step: usize) -> StepBy<Self>

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator, 

'Zips up' two iterators into a single iterator of pairs.

fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 

Takes a closure and creates an iterator which calls that closure on each element.

fn for_each<F>(self, f: F) where
    F: FnMut(Self::Item), 

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that [skip]s elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that yields elements based on a predicate.

fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> where
    P: FnMut(Self::Item) -> Option<B>, 

🔬 This is a nightly-only experimental API. (iter_map_while)

recently added

Creates an iterator that both yields elements based on a predicate and maps.

fn skip(self, n: usize) -> Skip<Self>

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: FnMut(&mut St, Self::Item) -> Option<B>, 

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    F: FnMut(Self::Item) -> U,
    U: IntoIterator, 

Creates an iterator that works like map, but flattens nested structure.

fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoIterator, 

Creates an iterator that flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first [None].

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item), 

Does something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

#[must_use = "if you really need to exhaust the iterator, consider `.for_each(drop)` instead"] fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where
    B: Default + Extend<Self::Item>,
    F: FnMut(&Self::Item) -> bool, 

Consumes an iterator, creating two collections from it.

fn partition_in_place<'a, T, P>(self, predicate: P) -> usize where
    P: FnMut(&T) -> bool,
    Self: DoubleEndedIterator<Item = &'a mut T>,
    T: 'a, 

🔬 This is a nightly-only experimental API. (iter_partition_in_place)

new API

Reorders the elements of this iterator in-place according to the given predicate, such that all those that return true precede all those that return false. Returns the number of true elements found.

fn is_partitioned<P>(self, predicate: P) -> bool where
    P: FnMut(Self::Item) -> bool, 

🔬 This is a nightly-only experimental API. (iter_is_partitioned)

new API

Checks if the elements of this iterator are partitioned according to the given predicate, such that all those that return true precede all those that return false.

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Ok = B>, 

An iterator method that applies a function as long as it returns successfully, producing a single, final value.

fn try_for_each<F, R>(&mut self, f: F) -> R where
    F: FnMut(Self::Item) -> R,
    R: Try<Ok = ()>, 

An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error.

fn fold<B, F>(self, init: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 

An iterator method that applies a function, producing a single, final value.

fn all<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: FnMut(&Self::Item) -> bool, 

Searches for an element of an iterator that satisfies a predicate.

fn find_map<B, F>(&mut self, f: F) -> Option<B> where
    F: FnMut(Self::Item) -> Option<B>, 

Applies function to the elements of iterator and returns the first non-none result.

fn try_find<F, E, R>(&mut self, f: F) -> Result<Option<Self::Item>, E> where
    F: FnMut(&Self::Item) -> R,
    R: Try<Ok = bool, Error = E>, 

🔬 This is a nightly-only experimental API. (try_find)

new API

Applies function to the elements of iterator and returns the first non-none result or the first error.

fn position<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool, 

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool,
    Self: ExactSizeIterator + DoubleEndedIterator, 

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator, 

Reverses an iterator's direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
    FromA: Default + Extend<A>,
    FromB: Default + Extend<B>,
    Self: Iterator<Item = (A, B)>, 

Converts an iterator of pairs into a pair of containers.

fn copied<'a, T>(self) -> Copied<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Copy, 

Creates an iterator which copies all of its elements.

fn cloned<'a, T>(self) -> Cloned<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Clone, 

Creates an iterator which [clone]s all of its elements.

fn cycle(self) -> Cycle<Self> where
    Self: Clone, 

Repeats an iterator endlessly.

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 

Sums the elements of an iterator.

fn product<P>(self) -> P where
    P: Product<Self::Item>, 

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where
    I: IntoIterator<Item = Self::Item>,
    Self::Item: Ord, 

Lexicographically compares the elements of this Iterator with those of another.

fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
    I: IntoIterator, 

🔬 This is a nightly-only experimental API. (iter_order_by)

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
    I: IntoIterator, 

🔬 This is a nightly-only experimental API. (iter_order_by)

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn eq<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are equal to those of another.

fn eq_by<I, F>(self, other: I, eq: F) -> bool where
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
    I: IntoIterator, 

🔬 This is a nightly-only experimental API. (iter_order_by)

Determines if the elements of this Iterator are equal to those of another with respect to the specified equality function.

fn ne<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

fn is_sorted(self) -> bool where
    Self::Item: PartialOrd<Self::Item>, 

🔬 This is a nightly-only experimental API. (is_sorted)

new API

Checks if the elements of this iterator are sorted.

fn is_sorted_by<F>(self, compare: F) -> bool where
    F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>, 

🔬 This is a nightly-only experimental API. (is_sorted)

new API

Checks if the elements of this iterator are sorted using the given comparator function.

fn is_sorted_by_key<F, K>(self, f: F) -> bool where
    F: FnMut(Self::Item) -> K,
    K: PartialOrd<K>, 

🔬 This is a nightly-only experimental API. (is_sorted)

new API

Checks if the elements of this iterator are sorted using the given key extraction function.