README.md in json_validator-0.0.1 vs README.md in json_validator-0.0.2
- old
+ new
@@ -1,34 +1,52 @@
# JsonValidator
+[](https://rubygems.org/gems/json_validator)
[](https://travis-ci.org/iainbeeston/json_validator)
[](https://codeclimate.com/github/iainbeeston/json_validator)
+
JsonValidator is an ActiveModel validator that validates any hash field against [JSONSchema](http://json-schema.org), returning errors in the model's own `errors` attribute.
This gem was originally written to provide deep validation of JSON attributes, which are available alongside primative types in recent versions of [PostgreSQL](http://www.postgresql.org), but it works equally well with ActiveModel objects.
Most of the functionality is dependent on the wonderful [json-schema](https://github.com/hoxworth/json-schema) gem.
## Usage
If you're using Ruby on Rails and ActiveRecord, add a validation to your model like this:
- class Foo < ActiveRecord::Base
- validates :bar, json: {
- schema: {
- '$schema' => 'http://json-schema.org/schema#',
- 'title': 'Universal spoons schema',
- 'properties': {
- 'handleSize': {
- 'type': 'integer',
- 'minimum': 0
- }
- },
- 'required': ['handleSize']
- }
- }
- end
+~~~ruby
+class Foo < ActiveRecord::Base
+ validates :bar, json: {
+ schema: JSON.parse(File.read('foo_schema.json'))
+ }
+end
+~~~
-Then whenever an instance of `Foo` is saved, `Foo.bar` (assumed to be a hash) will be validated against the JSON schema specified. In this case, `Foo.new(bar: { handleSize: -10 })` would be invalid, but `Foo.new(bar: { handleSize: 10 })` would be valid.
+And you have a schema file (ie. `foo_schema.json`) like this:
+
+~~~json
+{
+ "$schema": "http://json-schema.org/draft-04/schema#",
+ "title": "Universal spoons schema",
+ "properties": {
+ "handleSize": {
+ "type": "integer",
+ "minimum": 0
+ }
+ },
+ "required": ["handleSize"]
+}
+~~~
+
+Then whenever an instance of `Foo` is saved, `Foo.bar` (assumed to be a hash) will be validated against the JSON schema specified. So, for example:
+
+~~~ruby
+
+f = Foo.new(bar: { handleSize: -10 })
+f.valid? # false
+f.errors.full_messages # ["Bar is invalid (the property '#/handleSize' did not have a minimum value of 0, inclusively)"]
+
+~~~
The attribute being validated can be either a hash or a string (which will be parsed as JSON). The schema can be either a hash or a Proc that returns a hash (if you'd like to decide on the schema at runtime), and there's no reason why you could not load your schema from a .json file.