tcomb-json-schema/README.md

Transforms a JSON Schema to a tcomb type

Transforms a JSON Schema to a type [tcomb](https://github.com/gcanti/tcomb) type.

# Compatibility

- tcomb ^2.0.0 -> tcomb-json-schema ^0.2.5
- tcomb ^3.0.0 -> tcomb-json-schema ^0.3.0

# Playground

If you want to get a general feel for how this works please head over to https://gcanti.github.io/resources/json-schema-to-tcomb/playground/playground.html

# API

## transform(schema: JSONSchema): Type

**Example**

```js
var transform = require('tcomb-json-schema');

var TcombType = transform({
  "type": "string",
  "enum": ["Street", "Avenue", "Boulevard"]
});
```

## registerFormat(format: string, predicateOrType: (x: any) => boolean | Type): void

Registers a new format.

**Example**

```js
function isEmail(x) {
  return /(.)+@(.)+/.test(x);
}

transform.registerFormat('email', isEmail);

var TcombType = transform({
  "type": "string",
  "format": 'email'
});
```

## resetFormats(): void

Removes all registered formats.

```js
transform.resetFormats();
```

## registerType(typeName: string, type: tComb Supported types): void

Registers a new type.

**Example**

```js
var Str10 = t.subtype(t.Str, function (s) {
  return s.length <= 10;
}, 'Str10');

transform.registerType('string10', Str10);

var TcombType = transform({
  type: "string10"
});
```

## resetTypes(): void

Removes all registered types.

```js
transform.resetTypes();
```

# JSON Schema

## strings

type `string` accepts the property `pattern` which will be used as a predicate (the value of the string must match the [regular expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) defined in `pattern`). Example:

```
{
  "type": "string",
  "pattern": "^abc$"
}
```

The pattern may be either

* a simple string with a regex pattern, e.g. `^abc$` (example matching the exact word `abc`), or
* a string version of a regex literal with a leading and trailing slash and optional [regex flags](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Advanced_searching_with_flags) after the last slash, e.g. `/^abc$/i` (example matching `abc` case insensetive)

## enums

If you don't care of values you can describe enums as an array:


```js
"street_type": {
  "type": "string",
  "enum": ["Street", "Avenue", "Boulevard"]
}
```

or if you want to specify values, describe it as an object where the keys are the values:

```js
"street_type": {
  "type": "string",
  "enum": {
    st: "Street",
    ave: "Avenue",
    blvd: "Boulevard"
  }
}
```