Struct KeyValues 

pub struct KeyValues(/* private fields */);

Pairs of text in the order they were entered, like headers or settings: what the UI kit’s key_value field sends (meta[0][key], meta[0][value], …). Rows without a key are skipped, and a key entered twice keeps its last value.

It is stored (db::Json<KeyValues>) and serialized as a list of pairs, [["Origin", "Aceh"], ["Roast", "Medium"]], so the order holds (a JSON object would lose it in PostgreSQL’s JSONB), and reads back from that, or from an object; key_value("meta", "Meta", value=item.meta) shows what was saved.

#[derive(serde::Deserialize)]
struct Settings {
    #[serde(default)]
    headers: KeyValues,
}

impl Validate for Settings {
    fn rules(&self, v: &mut Validator) {
        v.field("headers", &self.headers).max(20);
    }
}
for (name, value) in form.headers.iter() {
    println!("{name}: {value}");
}
assert_eq!(form.headers.get("Accept"), None);

Implementations

impl KeyValues

pub fn new() -> Self

No pairs.

pub fn get(&self, key: &str) -> Option<&str>

The value of key, if there is one.

pub fn insert(&mut self, key: impl Into<String>, value: impl Into<String>)

Sets key to value, keeping its place if it was there.

pub fn iter(&self) -> impl Iterator<Item = (&str, &str)>

The pairs, in order.

pub fn len(&self) -> usize

How many pairs there are.

pub fn is_empty(&self) -> bool

Whether there are none.

pub fn into_vec(self) -> Vec<(String, String)>

The pairs as a Vec.

Trait Implementations

impl Clone for KeyValues

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for KeyValues

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

Formats the value using the given formatter.

impl Default for KeyValues

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for KeyValues

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Eq for KeyValues

impl FieldValue for KeyValues

fn inspect(&self) -> Inspected

What rules see of the value.

fn db_value(&self) -> DbValue

The value as a query parameter, for unique and exists.

impl<K: Into<String>, V: Into<String>> FromIterator<(K, V)> for KeyValues

fn from_iter<I: IntoIterator<Item = (K, V)>>(pairs: I) -> Self

Creates a value from an iterator.

impl PartialEq for KeyValues

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for KeyValues

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for KeyValues