# json_schema

A JSON Schema V4 and Hyperschema V4 parser and validator.

Validate some data based on a JSON Schema:

```
gem install json_schema
validate-schema schema.json data.json
```

## Programmatic

``` ruby
require "json"
require "json_schema"

# parse the schema - raise SchemaError if it's invalid
schema_data = JSON.parse(File.read("schema.json"))
schema = JsonSchema.parse!(schema_data)

# expand $ref nodes - raise SchemaError if unable to resolve
schema.expand_references!

# validate some data - raise ValidationError if it doesn't conform
data = JSON.parse(File.read("data.json"))
schema.validate!(data)

# iterate through hyperschema links
schema.links.each do |link|
  puts "#{link.method} #{link.href}"
end

# abort on first error, instead of listing them all:
schema.validate!(data, fail_fast: true)
```

Errors have a `message` (for humans), and `type` (for machines).
`ValidationError`s also include a `path`, a JSON pointer to the location in
the supplied document which violated the schema. See [errors](docs/errors.md)
for more info.

Non-bang methods return a two-element array, with `true`/`false` at index 0
to indicate pass/fail, and an array of errors at index 1 (if any).

Passing `fail_fast: true` (default: `false`) will cause the validator to abort
on the first error it encounters and report just that. Even on fully valid data
this can offer some speed improvement, since it doesn't have to collect error
messages that might be later discarded (think of e.g. the `anyOf` directive).

## Development

Run the test suite with:

```
rake
```

Or run specific suites or tests with:

```
ruby -Ilib -Itest test/json_schema/validator_test.rb
ruby -Ilib -Itest test/json_schema/validator_test.rb -n /anyOf/
```

## Release

1. Update the version in `json_schema.gemspec` as appropriate for [semantic
   versioning](http://semver.org) and add details to `CHANGELOG`.
2. Run the `release` task:

    ```
    bundle exec rake release
    ```
