jsonpath/src/lib.rs
2019-09-22 16:49:41 +09:00

471 lines
15 KiB
Rust

//! JsonPath implementation written in Rust.
//!
//! # Example
//! ```
//! extern crate jsonpath_lib as jsonpath;
//! #[macro_use] extern crate serde_json;
//! let json_obj = json!({
//! "store": {
//! "book": [
//! {
//! "category": "reference",
//! "author": "Nigel Rees",
//! "title": "Sayings of the Century",
//! "price": 8.95
//! },
//! {
//! "category": "fiction",
//! "author": "Evelyn Waugh",
//! "title": "Sword of Honour",
//! "price": 12.99
//! },
//! {
//! "category": "fiction",
//! "author": "Herman Melville",
//! "title": "Moby Dick",
//! "isbn": "0-553-21311-3",
//! "price": 8.99
//! },
//! {
//! "category": "fiction",
//! "author": "J. R. R. Tolkien",
//! "title": "The Lord of the Rings",
//! "isbn": "0-395-19395-8",
//! "price": 22.99
//! }
//! ],
//! "bicycle": {
//! "color": "red",
//! "price": 19.95
//! }
//! },
//! "expensive": 10
//! });
//!
//! let mut selector = jsonpath::selector(&json_obj);
//!
//! assert_eq!(selector("$.store.book[*].author").unwrap(),
//! vec![
//! "Nigel Rees", "Evelyn Waugh", "Herman Melville", "J. R. R. Tolkien"
//! ]);
//!
//! assert_eq!(selector("$..author").unwrap(),
//! vec![
//! "Nigel Rees", "Evelyn Waugh", "Herman Melville", "J. R. R. Tolkien"
//! ]);
//!
//! assert_eq!(selector("$.store.*").unwrap(),
//! vec![
//! &json!([
//! { "category": "reference", "author": "Nigel Rees", "title": "Sayings of the Century", "price": 8.95 },
//! { "category": "fiction", "author": "Evelyn Waugh", "title": "Sword of Honour", "price": 12.99 },
//! { "category": "fiction", "author": "Herman Melville", "title": "Moby Dick", "isbn": "0-553-21311-3", "price": 8.99 },
//! { "category": "fiction", "author": "J. R. R. Tolkien", "title": "The Lord of the Rings", "isbn": "0-395-19395-8", "price": 22.99 }
//! ]),
//! &json!({ "color": "red", "price": 19.95 })
//! ]);
//!
//! assert_eq!(selector("$.store..price").unwrap(),
//! vec![
//! 8.95, 12.99, 8.99, 22.99, 19.95
//! ]);
//!
//! assert_eq!(selector("$..book[2]").unwrap(),
//! vec![
//! &json!({
//! "category" : "fiction",
//! "author" : "Herman Melville",
//! "title" : "Moby Dick",
//! "isbn" : "0-553-21311-3",
//! "price" : 8.99
//! })
//! ]);
//!
//! assert_eq!(selector("$..book[-2]").unwrap(),
//! vec![
//! &json!({
//! "category" : "fiction",
//! "author" : "Herman Melville",
//! "title" : "Moby Dick",
//! "isbn" : "0-553-21311-3",
//! "price" : 8.99
//! })
//! ]);
//!
//! assert_eq!(selector("$..book[0,1]").unwrap(),
//! vec![
//! &json!({"category" : "reference","author" : "Nigel Rees","title" : "Sayings of the Century","price" : 8.95}),
//! &json!({"category" : "fiction","author" : "Evelyn Waugh","title" : "Sword of Honour","price" : 12.99})
//! ]);
//!
//! assert_eq!(selector("$..book[:2]").unwrap(),
//! vec![
//! &json!({"category" : "reference","author" : "Nigel Rees","title" : "Sayings of the Century","price" : 8.95}),
//! &json!({"category" : "fiction","author" : "Evelyn Waugh","title" : "Sword of Honour","price" : 12.99})
//! ]);
//!
//! assert_eq!(selector("$..book[:2]").unwrap(),
//! vec![
//! &json!({"category" : "reference","author" : "Nigel Rees","title" : "Sayings of the Century","price" : 8.95}),
//! &json!({"category" : "fiction","author" : "Evelyn Waugh","title" : "Sword of Honour","price" : 12.99})
//! ]);
//!
//! assert_eq!(selector("$..book[?(@.isbn)]").unwrap(),
//! vec![
//! &json!({"category" : "fiction","author" : "Herman Melville","title" : "Moby Dick","isbn" : "0-553-21311-3","price" : 8.99}),
//! &json!({"category" : "fiction","author" : "J. R. R. Tolkien","title" : "The Lord of the Rings","isbn" : "0-395-19395-8","price" : 22.99})
//! ]);
//!
//! assert_eq!(selector("$.store.book[?(@.price < 10)]").unwrap(),
//! vec![
//! &json!({"category" : "reference","author" : "Nigel Rees","title" : "Sayings of the Century","price" : 8.95}),
//! &json!({"category" : "fiction","author" : "Herman Melville","title" : "Moby Dick","isbn" : "0-553-21311-3","price" : 8.99})
//! ]);
//! ```
extern crate array_tool;
extern crate core;
extern crate env_logger;
#[macro_use]
extern crate log;
extern crate serde;
extern crate serde_json;
use serde_json::Value;
pub use parser::Parser;
pub use select::JsonPathError;
pub use select::{Selector, SelectorMut};
#[doc(hidden)]
mod ffi;
#[doc(hidden)]
mod parser;
#[doc(hidden)]
mod select;
/// It is a high-order function. it compile a jsonpath and then returns a closure that has JSON as argument. if you need to reuse a jsonpath, it is good for performance.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// let mut first_firend = jsonpath::compile("$..friends[0]");
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// let json = first_firend(&json_obj).unwrap();
///
/// assert_eq!(json, vec![
/// &json!({"name": "친구3", "age": 30}),
/// &json!({"name": "친구1", "age": 20})
/// ]);
/// ```
pub fn compile(path: &str) -> impl FnMut(&Value) -> Result<Vec<&Value>, JsonPathError> {
let node = parser::Parser::compile(path);
move |json| match &node {
Ok(node) => {
let mut selector = Selector::default();
selector.compiled_path(node).value(json).select()
}
Err(e) => Err(JsonPathError::Path(e.to_string())),
}
}
/// It is a high-order function. it returns a closure that has a jsonpath string as argument. you can use diffenent jsonpath for one JSON object.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// let mut selector = jsonpath::selector(&json_obj);
///
/// let json = selector("$..friends[0]").unwrap();
///
/// assert_eq!(json, vec![
/// &json!({"name": "친구3", "age": 30}),
/// &json!({"name": "친구1", "age": 20})
/// ]);
///
/// let json = selector("$..friends[1]").unwrap();
///
/// assert_eq!(json, vec![
/// &json!({"name": "친구4"}),
/// &json!({"name": "친구2", "age": 20})
/// ]);
/// ```
#[allow(clippy::needless_lifetimes)]
pub fn selector<'a>(json: &'a Value) -> impl FnMut(&str) -> Result<Vec<&'a Value>, JsonPathError> {
let mut selector = Selector::default();
let _ = selector.value(json);
move |path: &str| selector.str_path(path)?.reset_value().select()
}
/// It is the same to `selector` function. but it deserialize the result as given type `T`.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// extern crate serde;
/// #[macro_use] extern crate serde_json;
///
/// use serde::{Deserialize, Serialize};
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// #[derive(Deserialize, PartialEq, Debug)]
/// struct Friend {
/// name: String,
/// age: Option<u8>,
/// }
///
/// let mut selector = jsonpath::selector_as::<Friend>(&json_obj);
///
/// let json = selector("$..friends[0]").unwrap();
///
/// let ret = vec!(
/// Friend { name: "친구3".to_string(), age: Some(30) },
/// Friend { name: "친구1".to_string(), age: Some(20) }
/// );
/// assert_eq!(json, ret);
///
/// let json = selector("$..friends[1]").unwrap();
///
/// let ret = vec!(
/// Friend { name: "친구4".to_string(), age: None },
/// Friend { name: "친구2".to_string(), age: Some(20) }
/// );
///
/// assert_eq!(json, ret);
/// ```
pub fn selector_as<T: serde::de::DeserializeOwned>(
json: &Value,
) -> impl FnMut(&str) -> Result<Vec<T>, JsonPathError> + '_ {
let mut selector = Selector::default();
let _ = selector.value(json);
move |path: &str| selector.str_path(path)?.reset_value().select_as()
}
/// It is a simple select function. but it compile the jsonpath argument every time.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// let json = jsonpath::select(&json_obj, "$..friends[0]").unwrap();
///
/// assert_eq!(json, vec![
/// &json!({"name": "친구3", "age": 30}),
/// &json!({"name": "친구1", "age": 20})
/// ]);
/// ```
pub fn select<'a>(json: &'a Value, path: &str) -> Result<Vec<&'a Value>, JsonPathError> {
Selector::default().str_path(path)?.value(json).select()
}
/// It is the same to `select` function but it return the result as string.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// let ret = jsonpath::select_as_str(r#"
/// {
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]
/// }
/// "#, "$..friends[0]").unwrap();
///
/// assert_eq!(ret, r#"[{"name":"친구3","age":30},{"name":"친구1","age":20}]"#);
/// ```
pub fn select_as_str(json_str: &str, path: &str) -> Result<String, JsonPathError> {
let json = serde_json::from_str(json_str).map_err(|e| JsonPathError::Serde(e.to_string()))?;
let ret = Selector::default().str_path(path)?.value(&json).select()?;
serde_json::to_string(&ret).map_err(|e| JsonPathError::Serde(e.to_string()))
}
/// It is the same to `select` function but it deserialize the the result as given type `T`.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// extern crate serde;
/// #[macro_use] extern crate serde_json;
///
/// use serde::{Deserialize, Serialize};
///
/// #[derive(Deserialize, PartialEq, Debug)]
/// struct Person {
/// name: String,
/// age: u8,
/// phones: Vec<String>,
/// }
///
/// let ret: Vec<Person> = jsonpath::select_as(r#"
/// {
/// "person":
/// {
/// "name": "Doe John",
/// "age": 44,
/// "phones": [
/// "+44 1234567",
/// "+44 2345678"
/// ]
/// }
/// }
/// "#, "$.person").unwrap();
///
/// let person = Person {
/// name: "Doe John".to_string(),
/// age: 44,
/// phones: vec!["+44 1234567".to_string(), "+44 2345678".to_string()],
/// };
///
/// assert_eq!(ret[0], person);
/// ```
pub fn select_as<T: serde::de::DeserializeOwned>(
json_str: &str,
path: &str,
) -> Result<Vec<T>, JsonPathError> {
let json = serde_json::from_str(json_str).map_err(|e| JsonPathError::Serde(e.to_string()))?;
Selector::default().str_path(path)?.value(&json).select_as()
}
/// Delete(= replace with null) the JSON property using the jsonpath.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// let ret = jsonpath::delete(json_obj, "$..[?(20 == @.age)]").unwrap();
///
/// assert_eq!(ret, json!({
/// "school": {
/// "friends": [
/// null,
/// null
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]}));
/// ```
pub fn delete(value: Value, path: &str) -> Result<Value, JsonPathError> {
let mut selector = SelectorMut::default();
let value = selector.str_path(path)?.value(value).delete()?;
Ok(value.take().unwrap_or(Value::Null))
}
/// Select JSON properties using a jsonpath and transform the result and then replace it. via closure that implements `FnMut` you can transform the selected results.
///
/// ```rust
/// extern crate jsonpath_lib as jsonpath;
/// #[macro_use] extern crate serde_json;
///
/// use serde_json::Value;
///
/// let json_obj = json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 20},
/// {"name": "친구2", "age": 20}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]});
///
/// let ret = jsonpath::replace_with(json_obj, "$..[?(@.age == 20)].age", &mut |v| {
/// let age = if let Value::Number(n) = v {
/// n.as_u64().unwrap() * 2
/// } else {
/// 0
/// };
///
/// Some(json!(age))
/// }).unwrap();
///
/// assert_eq!(ret, json!({
/// "school": {
/// "friends": [
/// {"name": "친구1", "age": 40},
/// {"name": "친구2", "age": 40}
/// ]
/// },
/// "friends": [
/// {"name": "친구3", "age": 30},
/// {"name": "친구4"}
/// ]}));
/// ```
pub fn replace_with<F>(value: Value, path: &str, fun: &mut F) -> Result<Value, JsonPathError>
where
F: FnMut(Value) -> Option<Value>,
{
let mut selector = SelectorMut::default();
let value = selector.str_path(path)?.value(value).replace_with(fun)?;
Ok(value.take().unwrap_or(Value::Null))
}