Struct Cursor 

pub struct Cursor {
    pub field: String,
    pub value: CursorValue,
    pub direction: CursorDirection,
}

Fields

field: String

value: CursorValue

direction: CursorDirection

Implementations

impl Cursor

pub fn new( field: String, value: CursorValue, direction: CursorDirection, ) -> Self

pub fn encode(&self) -> Result<String, String>

pub fn decode(encoded: &str) -> Result<Self, String>

pub fn value_from_row<T: Serialize>( field: &str, row: &T, template: Option<&CursorValue>, ) -> Result<CursorValue, String>

Read the cursor field out of a serialized row.

The row is serialized with serde_json and field is looked up on the resulting object. A qualified name such as users.id falls back to its last segment (id), so cursors on table-qualified columns still resolve. See CursorValue::from_json for how template shapes the value.

pub fn from_row<T: Serialize>( field: impl Into<String>, row: &T, direction: CursorDirection, ) -> Result<Self, String>

Build a cursor anchored at row, for example to hand out a next_cursor from the last row of an offset page:

use paginator_utils::{Cursor, CursorDirection, CursorValue};
use serde::Serialize;

#[derive(Serialize)]
struct User { id: i64, name: String }

let last = User { id: 42, name: "Ada".into() };
let next = Cursor::from_row("id", &last, CursorDirection::After).unwrap();
assert_eq!(next.value, CursorValue::Int(42));

pub fn at_row<T: Serialize>( &self, row: &T, direction: CursorDirection, ) -> Result<Self, String>

A cursor on the same field as self, anchored at row. The value keeps the variant of self.value, so a Uuid cursor stays a Uuid cursor.

Trait Implementations

impl Clone for Cursor

fn clone(&self) -> Cursor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Cursor

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Cursor

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Cursor

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Cursor

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Cursor