# Liquid JSON template library
This library is a small wrapper around the [Liquid](https://shopify.github.io/liquid/) templating engine that recursively processes structured JSON values for Liquid templates.
Liquid JSON templates help templatize JSON files used in configuration or RPC transmission.
## Usage
```rust
use serde_json::json;
let template_json = json!({"this":"{{myval}}"});
let template_data = json!({"myval": 5});
let tmpl = liquid_json::LiquidJson::new(template_json);
let actual = tmpl.render(&template_data).unwrap();
let expected = json!({"this": 5}); // {{myval}} is replaced with 5
assert_eq!(actual, expected);
```
## Features
The `serde` feature (enabled by default) exposes `LiquidJsonValue`. `LiquidJsonValue` is a wrapper around `LiquidJson` (and `serde_json::Value`) that lets you embed `LiquidJson` templates in your structs, e.g.
```rust
use serde_json::json;
#[derive(serde::Serialize, serde::Deserialize, Debug, PartialEq)]
struct YourStruct {
inner_liquid: liquid_json::LiquidJsonValue,
}
let json_data = json!({"inner_liquid":"{{myval}}"});
let template_data = json!({"myval": 5});
let yours: YourStruct = serde_json::from_value(json_data).unwrap();
let actual = yours.inner_liquid.render(&template_data).unwrap();
```
## Additional Filters
This library extends the default Liquid filters with the following:
- `json`: parses a JSON string into a Liquid object (recursing through arrays/objects as necessary).
- `each`: apply a template over every element in an array.
- `output`: mark a Liquid value as the output value of the template. Useful when you want to return an array or an object instead of a string.
### Example
Those filters can combine to produce complex JSON structures from simple input data. E.g.:
The input data:
```json
{
"to": ["john@example.com", "jane@example.com"]
}
```
Applied to the liquid JSON template:
```json
{
```
Produces the JSON:
```json
{
"recipients": [
{
"email": "john@example.com"
},
{
"email": "jane@example.com"
}
]
}
```