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#![allow(clippy::all)]
#![allow(clippy::needless_question_mark)]
//! Pagination & Filtering Example
//!
//! This example demonstrates:
//! - Offset pagination
//! - Cursor pagination
//! - Multi-field sorting
//! - Query parameter filtering
//! - Field selection
//!
//! Run with:
//! ```bash
//! cargo run --example pagination_example
//! ```
//!
//! Test with:
//! ```bash
//! # Pagination
//! curl "http://localhost:3000/users?page=2&per_page=5"
//!
//! # Sorting
//! curl "http://localhost:3000/users?sort=-created_at,name"
//!
//! # Filtering
//! curl "http://localhost:3000/users?status=active&age__gte=18"
//!
//! # Field selection
//! curl "http://localhost:3000/users?fields=id,name,email"
//!
//! # Combined
//! curl "http://localhost:3000/users?page=1&sort=-created_at&status=active&fields=id,name"
//!
//! # Cursor pagination
//! curl "http://localhost:3000/users/cursor?limit=10"
//! ```
use armature_core::handler::from_legacy_handler;
use armature_core::*;
use serde::{Deserialize, Serialize};
use std::sync::Arc;
#[derive(Debug, Clone, Serialize, Deserialize)]
struct User {
id: u64,
name: String,
email: String,
status: String,
age: u32,
created_at: String,
}
// Mock database
fn get_mock_users() -> Vec<User> {
vec![
User {
id: 1,
name: "Alice Johnson".to_string(),
email: "alice@example.com".to_string(),
status: "active".to_string(),
age: 28,
created_at: "2024-01-15".to_string(),
},
User {
id: 2,
name: "Bob Smith".to_string(),
email: "bob@example.com".to_string(),
status: "active".to_string(),
age: 34,
created_at: "2024-01-10".to_string(),
},
User {
id: 3,
name: "Charlie Brown".to_string(),
email: "charlie@example.com".to_string(),
status: "inactive".to_string(),
age: 22,
created_at: "2024-01-20".to_string(),
},
User {
id: 4,
name: "Diana Prince".to_string(),
email: "diana@example.com".to_string(),
status: "active".to_string(),
age: 31,
created_at: "2024-01-12".to_string(),
},
User {
id: 5,
name: "Eve Adams".to_string(),
email: "eve@example.com".to_string(),
status: "active".to_string(),
age: 26,
created_at: "2024-01-18".to_string(),
},
User {
id: 6,
name: "Frank Miller".to_string(),
email: "frank@example.com".to_string(),
status: "inactive".to_string(),
age: 45,
created_at: "2024-01-08".to_string(),
},
User {
id: 7,
name: "Grace Lee".to_string(),
email: "grace@example.com".to_string(),
status: "active".to_string(),
age: 29,
created_at: "2024-01-22".to_string(),
},
User {
id: 8,
name: "Henry Ford".to_string(),
email: "henry@example.com".to_string(),
status: "active".to_string(),
age: 38,
created_at: "2024-01-14".to_string(),
},
]
}
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// Initialize logging
let _guard = LogConfig::default().init();
info!("Pagination & Filtering Example");
info!("==============================");
// Create router
let mut router = Router::new();
// Offset pagination endpoint
router.add_route(Route {
method: HttpMethod::GET,
path: "/users".to_string(),
handler: from_legacy_handler(Arc::new(|req: HttpRequest| {
Box::pin(async move {
// Parse query parameters
let query = QueryParams::from_hashmap(&req.query_params);
// Get all users
let mut users = get_mock_users();
// Apply filters
if !query.filter.is_empty() {
users.retain(|user| {
for condition in &query.filter.conditions {
match condition.field.as_str() {
"status" => {
if let Some(ref value) = condition.value {
if user.status != *value {
return false;
}
}
}
"age" => {
if let Some(ref value) = condition.value {
if let Ok(age) = value.parse::<u32>() {
match condition.operator {
FilterOperator::Eq => {
if user.age != age {
return false;
}
}
FilterOperator::Gte => {
if user.age < age {
return false;
}
}
FilterOperator::Lte => {
if user.age > age {
return false;
}
}
FilterOperator::Gt => {
if user.age <= age {
return false;
}
}
FilterOperator::Lt => {
if user.age >= age {
return false;
}
}
_ => {}
}
}
}
}
_ => {}
}
}
true
});
}
let total = users.len();
// Apply sorting
if !query.sort.is_empty() {
for sort_field in query.sort.fields.iter().rev() {
match sort_field.field.as_str() {
"name" => {
users.sort_by(|a, b| {
let cmp = a.name.cmp(&b.name);
match sort_field.direction {
SortDirection::Asc => cmp,
SortDirection::Desc => cmp.reverse(),
}
});
}
"created_at" => {
users.sort_by(|a, b| {
let cmp = a.created_at.cmp(&b.created_at);
match sort_field.direction {
SortDirection::Asc => cmp,
SortDirection::Desc => cmp.reverse(),
}
});
}
"age" => {
users.sort_by(|a, b| {
let cmp = a.age.cmp(&b.age);
match sort_field.direction {
SortDirection::Asc => cmp,
SortDirection::Desc => cmp.reverse(),
}
});
}
_ => {}
}
}
}
// Apply pagination
let offset = query.pagination.offset();
let limit = query.pagination.limit();
let paginated_users: Vec<User> =
users.into_iter().skip(offset).take(limit).collect();
// Apply field selection
let response_json = if query.fields.is_active() {
let filtered: Vec<serde_json::Value> = paginated_users
.iter()
.map(|user| {
let mut obj = serde_json::json!({});
if query.fields.should_include("id") {
obj["id"] = serde_json::json!(user.id);
}
if query.fields.should_include("name") {
obj["name"] = serde_json::json!(&user.name);
}
if query.fields.should_include("email") {
obj["email"] = serde_json::json!(&user.email);
}
if query.fields.should_include("status") {
obj["status"] = serde_json::json!(&user.status);
}
if query.fields.should_include("age") {
obj["age"] = serde_json::json!(user.age);
}
if query.fields.should_include("created_at") {
obj["created_at"] = serde_json::json!(&user.created_at);
}
obj
})
.collect();
let response = PaginatedResponse::new(filtered, query.pagination, total);
serde_json::to_value(&response).map_err(|e| Error::Internal(e.to_string()))?
} else {
let response = PaginatedResponse::new(paginated_users, query.pagination, total);
serde_json::to_value(&response).map_err(|e| Error::Internal(e.to_string()))?
};
Ok(HttpResponse::ok().with_json(&response_json)?)
})
})),
constraints: None,
});
// Cursor pagination endpoint
router.add_route(Route {
method: HttpMethod::GET,
path: "/users/cursor".to_string(),
handler: from_legacy_handler(Arc::new(|req: HttpRequest| {
Box::pin(async move {
// Parse cursor pagination
let pagination = CursorPagination::from_query_params(&req.query_params);
let users = get_mock_users();
// In real app, cursor would be an actual database cursor
// For demo, we'll use simple offset
let cursor_offset = pagination
.cursor
.as_ref()
.and_then(|c| c.parse::<usize>().ok())
.unwrap_or(0);
let total = users.len();
let paginated_users: Vec<User> = users
.into_iter()
.skip(cursor_offset)
.take(pagination.limit)
.collect();
let next_cursor = if cursor_offset + pagination.limit < total {
Some((cursor_offset + pagination.limit).to_string())
} else {
None
};
let response = PaginatedResponse::with_cursor(
paginated_users,
pagination.limit,
total,
next_cursor,
);
Ok(HttpResponse::ok().with_json(&response)?)
})
})),
constraints: None,
});
// Home endpoint with documentation
router.add_route(Route {
method: HttpMethod::GET,
path: "/".to_string(),
handler: from_legacy_handler(Arc::new(|_req: HttpRequest| {
Box::pin(async move {
Ok(HttpResponse::ok().with_json(&serde_json::json!({
"message": "Pagination & Filtering Example",
"endpoints": {
"GET /users": "List users with pagination",
"GET /users/cursor": "List users with cursor pagination"
},
"features": {
"pagination": "?page=2&per_page=5",
"sorting": "?sort=-created_at,name (- prefix = DESC)",
"filtering": "?status=active&age__gte=18",
"field_selection": "?fields=id,name,email",
"search": "?q=search term",
"combined": "?page=1&sort=-created_at&status=active&fields=id,name"
},
"filter_operators": {
"eq": "Equal (default)",
"ne": "Not equal",
"gt": "Greater than",
"gte": "Greater than or equal",
"lt": "Less than",
"lte": "Less than or equal",
"in": "In list",
"contains": "Contains substring",
"starts_with": "Starts with",
"ends_with": "Ends with"
},
"examples": {
"pagination": "curl 'http://localhost:3000/users?page=2&per_page=5'",
"sorting": "curl 'http://localhost:3000/users?sort=-created_at,name'",
"filtering": "curl 'http://localhost:3000/users?status=active&age__gte=18'",
"fields": "curl 'http://localhost:3000/users?fields=id,name,email'",
"combined": "curl 'http://localhost:3000/users?page=1&sort=-age&status=active&fields=id,name'",
"cursor": "curl 'http://localhost:3000/users/cursor?limit=3'"
}
}))?)
})
})),
constraints: None,
});
// Build application
let container = Container::new();
let app = Application::new(container, router);
info!("\n✓ Server started on http://localhost:3000");
info!("\nFeatures:");
info!(" ✓ Offset pagination (page/per_page)");
info!(" ✓ Cursor pagination (cursor/limit)");
info!(" ✓ Multi-field sorting");
info!(" ✓ Query parameter filtering");
info!(" ✓ Field selection (sparse fieldsets)");
info!("\nExamples:");
info!(" curl 'http://localhost:3000/users?page=2&per_page=3'");
info!(" curl 'http://localhost:3000/users?sort=-created_at,name'");
info!(" curl 'http://localhost:3000/users?status=active&age__gte=25'");
info!(" curl 'http://localhost:3000/users?fields=id,name,email'");
info!(" curl 'http://localhost:3000/users?page=1&sort=-age&status=active'");
info!("\nPress Ctrl+C to stop\n");
app.listen(3000).await?;
Ok(())
}