An open API service indexing awesome lists of open source software.

https://github.com/georged19/json-logic-go

Build complex rules, serialize them as JSON, and execute them in GO
https://github.com/georged19/json-logic-go

go golang json jsonlogic parser

Last synced: 20 days ago
JSON representation

Build complex rules, serialize them as JSON, and execute them in GO

Awesome Lists containing this project

README

          

# json-logic-go

This parser accepts [JsonLogic](http://jsonlogic.com) rules and executes them in Go.

The JsonLogic format is designed to allow you to share rules (logic) between front-end and back-end code (regardless of language difference), even to store logic along with a record in a database. JsonLogic is documented extensively at [JsonLogic.com](http://jsonlogic.com), including examples of every [supported operation](http://jsonlogic.com/operations.html) and a place to [try out rules in your browser](http://jsonlogic.com/play.html).

The same format can be executed in the following libraries:
- JavaScript [json-logic-js](https://github.com/jwadhams/json-logic-js/)
- PHP [json-logic-php](https://github.com/jwadhams/json-logic-php/)
- Python [json-logic-py](https://github.com/nadirizr/json-logic-py)
- Ruby [json-logic-ruby](https://github.com/bhgames/json-logic-ruby)
- Go [json-logic-go](https://github.com/GeorgeD19/json-logic-go)

## Examples

### A note about types

This is a GO interpreter of a format designed to be transmitted and stored as JSON. So it makes sense to conceptualize the rules in JSON.

Expressed in JSON, a JsonLogic rule is always one key, with an array of values.

```GO
rule := `{"==":["apples", "apples"]}`
result, err := jsonlogic.Run(rule)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// true
```

### Simple
```GO
rule := `{"==":[1, 1]}`
result, err := jsonlogic.Run(rule)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// true
```

This is a simple test, equivalent to `1 == 1`. A few things about the format:

1. The operator is always in the "key" position. There is only one key per JsonLogic rule.
2. The values are typically an array.
3. Each value can be a string, number, boolean, array, or null

### Compound
Here we're beginning to nest rules.

```GO
rule := `{"and": [
{ ">": [3,1] },
{ "<": [1,3] }
] }`
result, err := jsonlogic.Run(rule)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// true
```

### Data-Driven

Obviously these rules aren't very interesting if they can only take static literal data. Typically `jsonlogic.Apply` will be called with a rule object and a data object however you can also use `jsonlogic.Run` to run a rule object without a data object. You can use the `var` operator to get attributes of the data object:

```GO
rule := `{ "var": ["a"] }`
data := `{ "a": 1, "b": 2 }`
result, err := jsonlogic.Apply(rule, data)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// 1
```

If you like, we support [syntactic sugar](https://en.wikipedia.org/wiki/Syntactic_sugar) on unary operators to skip the array around values:

You can also use the `var` operator to access an array by numeric index:

```GO
rule := `{ "var": 1 }`
data := `[ "apple", "banana", "carrot" ]`
result, err := jsonlogic.Apply(rule, data)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// "banana"
```

Here's a complex rule that mixes literals and data. The pie isn't ready to eat unless it's cooler than 110 degrees, *and* filled with apples.

```GO
rule := `{ "and": [
{ "<": [ { "var": "temp" }, 110 ] },
{ "==": [ { "var": "pie.filling" }, "apple" ] }
] }`
data := `{ "temp": 100, "pie": { "filling": "apple" } }`
result, err := jsonlogic.Apply(rule, data)
if err != nil {
fmt.Println(err)
}
fmt.Println(result)
// true
```

## Installation

```
go get github.com/GeorgeD19/json-logic-go
```

If that doesn't suit you, and you want to manage updates yourself, the entire library is self-contained in jsonlogic.go and you can download it straight into your project as you see fit.

```
curl -O https://raw.githubusercontent.com/GeorgeD19/json-logic-go/master/jsonlogic.go
```