Jared Wolff
a404342559
When there are no items, total_pages is 0 and `total_pages - 1` causes a subtract-with-overflow panic on usize. Guard the subtraction with a `total_pages > 0` check.
103 lines
2.6 KiB
Rust
Executable File
103 lines
2.6 KiB
Rust
Executable File
use serde::{Deserialize, Serialize};
|
|
|
|
/// A DTO to represent pagination information
|
|
#[derive(Debug, Clone, Serialize, Deserialize)]
|
|
pub struct PaginationDto {
|
|
/// Current page (starts at 0)
|
|
pub page: usize,
|
|
/// Page size
|
|
pub page_size: usize,
|
|
/// Total number of items
|
|
pub total_items: usize,
|
|
/// Total number of pages
|
|
pub total_pages: usize,
|
|
/// Indicates if there is a next page
|
|
pub has_next: bool,
|
|
/// Indicates if there is a previous page
|
|
pub has_prev: bool,
|
|
}
|
|
|
|
/// A DTO to represent a pagination request
|
|
#[derive(Debug, Clone, Serialize, Deserialize)]
|
|
pub struct PaginationRequestDto {
|
|
/// Requested page (starts at 0)
|
|
#[serde(default)]
|
|
pub page: usize,
|
|
/// Requested page size
|
|
#[serde(default = "default_page_size")]
|
|
pub page_size: usize,
|
|
}
|
|
|
|
/// A DTO to represent a paginated response
|
|
#[derive(Debug, Clone, Serialize, Deserialize)]
|
|
pub struct PaginatedResponseDto<T> {
|
|
/// Data on the current page
|
|
pub items: Vec<T>,
|
|
/// Pagination information
|
|
pub pagination: PaginationDto,
|
|
}
|
|
|
|
impl Default for PaginationRequestDto {
|
|
fn default() -> Self {
|
|
Self {
|
|
page: 0,
|
|
page_size: default_page_size(),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Function to set the default page size
|
|
fn default_page_size() -> usize {
|
|
100 // By default, 100 items per page
|
|
}
|
|
|
|
impl PaginationRequestDto {
|
|
/// Calculates the offset for paginated queries
|
|
pub fn offset(&self) -> usize {
|
|
self.page * self.page_size
|
|
}
|
|
|
|
/// Calculates the limit for paginated queries
|
|
pub fn limit(&self) -> usize {
|
|
self.page_size
|
|
}
|
|
|
|
/// Validates and adjusts the pagination parameters
|
|
pub fn validate_and_adjust(&self) -> Self {
|
|
let mut page = self.page;
|
|
let mut page_size = self.page_size;
|
|
|
|
// Ensure the page is at least 0
|
|
if page < 1 {
|
|
page = 0;
|
|
}
|
|
|
|
// Ensure the page size is between 10 and 500
|
|
page_size = page_size.clamp(10, 500);
|
|
|
|
Self { page, page_size }
|
|
}
|
|
}
|
|
|
|
impl<T> PaginatedResponseDto<T> {
|
|
/// Creates a new paginated response from the data and pagination information
|
|
pub fn new(items: Vec<T>, page: usize, page_size: usize, total_items: usize) -> Self {
|
|
let total_pages = if total_items == 0 {
|
|
0
|
|
} else {
|
|
total_items.div_ceil(page_size)
|
|
};
|
|
|
|
let pagination = PaginationDto {
|
|
page,
|
|
page_size,
|
|
total_items,
|
|
total_pages,
|
|
has_next: total_pages > 0 && page < total_pages - 1,
|
|
has_prev: page > 0,
|
|
};
|
|
|
|
Self { items, pagination }
|
|
}
|
|
}
|