【大家的项目】部分移植nodejs的json-rules-engine到rust

json-rules-engine

最近有一个老旧的nodejs项目需要移植到rust，其中一部分严重依赖nodejs的json-rules-engine库，于是昨天抽时间移植了该项目的部分功能到rust，尚不支持优先级和缓存。

项目地址

​​https://github.com/GopherJ/json-rules-engine-rs​​

安装

[dependencies]
json-rules-engine = { version = "0.7.0", features = ["email"] }
tokio = { version = "0.3.3", features = ["macros"] }
serde_json = { version = "*" }
anyhow = { version = "*" }

特性

• 很多的类型安全的内置操作符如, ​​string_equals​​, ​​int_in_range​​...等
• 支持All, Any, AtLeast操作符
• 支持匹配成功后的多个对应事件如HTTP post到callback_url，发送邮件，适合报警
• json序列化反序列化
• 内置moustache支持
• 自定义脚本
• 自定义函数

实例

use json_rules_engine::{Engine, Rule, Map, from_dynamic};
use serde_json::json;
use serde::{Serialize, Deserialize};

#[derive(Deserialize, Serialize)]
struct Facts {
name: String,
age: u8,
action: String
}

fn age_greater_than20_less_than_inclusive25(p: Map) -> bool {
let facts: Facts = from_dynamic(&p.into()).unwrap();
facts.age > 20 && facts.age <= 25
}

#[tokio::main]
async main() -> anyhow::Result<()> {
let sendgrid_api_key = "kjsldkjslkjlwkjkjew";

let rule_json = json!({
"conditions": {
"and": [
{
"field": "name",
"operator": "string_equals",
"value": "Cheng JIANG"
},
{
"field": "age",
"operator": "int_in_range",
"value": [20, 25]
},
{
"script": "facts.age > 20 && facts.age <= 25",
},
{
"script": "my_function(facts)",
},
{
"field": "action",
"operator": "string_equals",
"value": "coding in rust"
}
]
},
"events": [
{
"type": "post_to_callback_url",
"params": {
"callback_url": "http://example.com/people/conding_in_rust",
"type": "info",
"title": "Another person is coding in rust",
"message": "Name: {{ name }}, Age: {{ age }}, Action: {{ action }},"
}
},
{
"type": "email_notification",
"params": {
"from": "alex_cj96@foxmail.com",
"to": ["abc.def@gmail.com"],
"type": "info",
"title": "Another person is coding in rust",
"message": "Name: {{ name }}, Age: {{ age }}, Action: {{ action }},"
}
}
]
});

let rule: Rule = serde_json::from_str::<Rule>(&serde_json::to_string(&rule_json).unwrap()).unwrap();

let mut engine = Engine::new(sendgrid_api_key);
engine.add_rule(rule);
engine.add_function("my_function", age_greater_than20_less_than_inclusive25);

let facts = json!({
"name": "Cheng JIANG",
"age": 24,
"action": "coding in rust",
});

let rule_results = engine.run(&facts).await?;

println!("{:?}", rule_results);
}