# jsonpath_lib

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`Rust` 버전 [JsonPath](https://goessner.net/articles/JsonPath/) 구현으로 `Webassembly`와 `Javascript`에서도 유사한 API 인터페이스를 제공 한다.

It is JsonPath [JsonPath](https://goessner.net/articles/JsonPath/) engine written in `Rust`. it provide a similar API interface in `Webassembly` and` Javascript` too.

- [Webassembly Demo](https://freestrings.github.io/jsonpath/)
- [NPM jsonpath-wasm - webassembly](https://www.npmjs.com/package/jsonpath-wasm)

## Rust API

jsonpath_lib crate

Go to [`jsonpath_lib` creates.io](https://crates.io/crates/jsonpath_lib)

```rust
extern crate jsonpath_lib as jsonpath;
```


Rust - jsonpath::Selector struct

```rust
#[derive(Deserialize, PartialEq, Debug)]
struct Friend {
    name: String,
    age: Option<u8>,
}

let json_obj = json!({
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
]});

let mut selector = Selector::new();

let result = selector
    .path("$..[?(@.age >= 30)]").unwrap()
    .value(&json_obj)
    .select().unwrap();

assert_eq!(vec![&json!({"name": "친구3", "age": 30})], result);

let result = selector.select_as_str().unwrap();
assert_eq!(r#"[{"name":"친구3","age":30}]"#, result);

let result = selector.select_as::<Friend>().unwrap();
assert_eq!(vec![Friend { name: "친구3".to_string(), age: Some(30) }], result);
```


Rust - jsonpath::SelectorMut struct

```rust
let json_obj = json!({
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
]});

let mut selector_mut = SelectorMut::new();

let result = selector_mut
    .str_path("$..[?(@.age == 20)].age").unwrap()
    .value(json_obj)
    .replace_with(&mut |v| {
        let age = if let Value::Number(n) = v {
            n.as_u64().unwrap() * 2
        } else {
            0
        };

        Some(json!(age))
    }).unwrap()
    .take().unwrap();

assert_eq!(result, json!({
    "school": {
        "friends": [
            {"name": "친구1", "age": 40},
            {"name": "친구2", "age": 40}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
]}));
```


Rust - jsonpath::select(json: &serde_json::value::Value, jsonpath: &str)

```rust
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})
]);
```


Rust - jsonpath::select_as_str(json_str: &str, jsonpath: &str)

```rust
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}]"#);
```


Rust - jsonpath::select_as<T: `serde::de::DeserializeOwned`>(json_str: &str, jsonpath: &str)

```rust
#[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);
```


Rust - jsonpath::Compiled::compile(jsonpath: &str)

```rust
let template = jsonpath::Compiled::compile("$..friends[0]").unwrap();

let json_obj = json!({
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
]});

let json = template.select(&json_obj).unwrap();

assert_eq!(json, vec![
    &json!({"name": "친구3", "age": 30}),
    &json!({"name": "친구1", "age": 20})
]);
```


Rust - jsonpath::selector(json: &serde_json::value::Value)

```rust
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})
]);
```


Rust - jsonpath::selector_as<T: serde::de::DeserializeOwned>(json: &serde_json::value::Value)

```rust
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);
```


Rust - jsonpath::delete(value: &Value, path: &str)

```rust
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"}
]}));
```


Rust - jsonpath::replace_with<F: FnMut(&Value) -> Value>(value: &Value, path: &str, fun: &mut F)

```rust
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"}
]}));
```


[Rust - Other Examples](https://github.com/freestrings/jsonpath/wiki/rust-examples)

## Javascript API

npm package

##### jsonpath-wasm

Goto [`jsonpath-wasm` npmjs.org](https://www.npmjs.com/package/jsonpath-wasm)

```javascript
// browser
import * as jsonpath from "jsonpath-wasm";
// NodeJs
const jsonpath = require('jsonpath-wasm');
```

##### jsonpath-wasm
`wasm-bindgen` 리턴 타입 제약 때문에 빌더 패턴은 지원하지 않는다.

It does not support `builder-pattern` due to the `return type` restriction of `wasm-bindgen`.

```javascript
let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let ret = [
    {"name": "친구3", "age": 30},
    {"name": "친구1", "age": 20}
];

let selector = new jsonpath.Selector();
selector.path('$..friends[0]');
selector.value(jsonObj);

let retObj = selector.select();

console.log(JSON.stringify(ret) == JSON.stringify(retObj));

// => true
```

빌더 패턴 제약은 `Selector class`와 동일하다.

```javascript
let jsonObj = {
    'school': {
        'friends': [
            {'name': '친구1', 'age': 20},
            {'name': '친구2', 'age': 20},
        ],
    },
    'friends': [
        {'name': '친구3', 'age': 30},
        {'name': '친구4'},
    ],
};

let selector = new jsonpath.SelectorMut();
selector.path('$..[?(@.age == 20)]');

{
    selector.value(jsonObj);
    selector.deleteValue();

    let resultObj = {
        'school': {'friends': [null, null]},
        'friends': [
            {'name': '친구3', 'age': 30},
            {'name': '친구4'},
        ],
    };
    console.log(JSON.stringify(selector.take()) !== JSON.stringify(resultObj));
    
    // => true
}

{
    selector.value(jsonObj);
    selector.replaceWith((v) => {
        v.age = v.age * 2;
        return v;
    });

    let resultObj = {
        'school': {
            'friends': [
                {'name': '친구1', 'age': 40},
                {'name': '친구2', 'age': 40},
            ],
        },
        'friends': [
            {'name': '친구3', 'age': 30},
            {'name': '친구4'},
        ],
    };
    console.log(JSON.stringify(selector.take()) !== JSON.stringify(resultObj));
    
    // => true
}
```


Javascript - jsonpath.select(json: string|object, jsonpath: string)

```javascript
let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let ret = [
    {"name": "친구3", "age": 30},
    {"name": "친구1", "age": 20}
];


let selectAsString = jsonpath.select(JSON.stringify(jsonObj), '$..friends[0]');
let selectAsObj = jsonpath.select(jsonObj, '$..friends[0]');

console.log(
    JSON.stringify(ret) == JSON.stringify(selectAsString),
    JSON.stringify(ret) == JSON.stringify(selectAsObj)
);

// => true, true
```


Javascript - jsonpath.compile(jsonpath: string)

```javascript
let error = jsonpath.compile('');
console.log(typeof error, error); //string 'path error'

let template = jsonpath.compile('$..friends[0]');

let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let ret = [
    {"name": "친구3", "age": 30},
    {"name": "친구1", "age": 20}
];

let selectAsString = template(JSON.stringify(jsonObj));
let selectAsObj = template(jsonObj);

console.log(
    JSON.stringify(ret) == JSON.stringify(selectAsString),
    JSON.stringify(ret) == JSON.stringify(selectAsObj)
);

// => true, true

let jsonObj2 = {
    "school": {
        "friends": [
            {"name": "Millicent Norman"},
            {"name": "Vincent Cannon"}
        ]
    },
    "friends": [ {"age": 30}, {"age": 40} ]
};

let ret2 = [
    {"age": 30},
    {"name": "Millicent Norman"}
];

let selectAsString2 = template(JSON.stringify(jsonObj2));
let selectAsObj2 = template(jsonObj2);

console.log(
        JSON.stringify(ret2) == JSON.stringify(selectAsString2),
        JSON.stringify(ret2) == JSON.stringify(selectAsObj2)
);

// => true, true
```
    

Javascript - jsonpath.selector(json: string|object)

```javascript
let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let ret1 = [
    {"name": "친구3", "age": 30},
    {"name": "친구1", "age": 20}
];

let ret2 = [
    {"name": "친구4"},
    {"name": "친구2", "age": 20}
];

let selector = jsonpath.selector(jsonObj);
// or as json string 
// let selector = jsonpath.selector(JSON.stringify(jsonObj));

let select1 = selector('$..friends[0]');
let select2 = selector('$..friends[1]');

console.log(
    JSON.stringify(ret1) == JSON.stringify(select1),
    JSON.stringify(ret2) == JSON.stringify(select2)
);

// => true, true
```


Javascript - jsonpath.deleteValue(json: string|object, path: string)

```javascript
let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let _1 = jsonpath.deleteValue(jsonObj, '$..friends[0]');
let result = jsonpath.deleteValue(_1, '$..friends[1]');

console.log(JSON.stringify(result) !== JSON.stringify({
    "school": { "friends": [null, null]},
    "friends": [null, null]
}));

// => true

```


Javascript - jsonpath.replaceWith(json: string|object, path: string, fun: function(json: object) => json: object

```javascript
let jsonObj = {
    "school": {
        "friends": [
            {"name": "친구1", "age": 20},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 30},
        {"name": "친구4"}
    ]
};

let result = jsonpath.replaceWith(jsonObj, '$..friends[0]', (v) => {
    v.age = v.age * 2;
    return v;
});

console.log(JSON.stringify(result) === JSON.stringify({
    "school": {
        "friends": [
            {"name": "친구1", "age": 40},
            {"name": "친구2", "age": 20}
        ]
    },
    "friends": [
        {"name": "친구3", "age": 60},
        {"name": "친구4"}
    ]
}));

// => true

```


[Javascript - Other Examples](https://github.com/freestrings/jsonpath/wiki/Javascript-examples)