backbone-blueprint

Create object hierarchies based on json schema

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Creates model/collection hierarchies based on JSON schema.

Based on JSON-Schema specification, but it's slightly modified regards handling relations etc.

Example

var addressSchema = exports.addressSchema = {
  id: '/schemas/address',
  title: 'Address',
  type: 'object',
  properties: {
    street: { type: 'string' },
    city: {type: 'string'},
    country: {type: 'string'}
  }
};

var Address = Model.extend({
  type: 'address',
  schema: addressSchema
});

var address = new Address({
  street: '221B Baker Street ',
  city: 'London',
  country: 'England'
});

Features

Relations

Relations are defined as

type: 'relation'
collection/model: ModelName

Thus relations can be either Models or Collections.

Example

var Addresses = exports.Addresses = Collection.extend({
  model: Address
});

var personSchema = exports.personSchema = {
  id: '/schemas/person',
  type: 'object',
  properties: {
   addresses : {
      type: 'relation',
      collection: Addresses
    }
  }
};

var person = new Person({
  addresses: [{street: 'Baker Street', city: 'London', country: 'GB'}]
});

console.log(person.get('addresses').at(0).get('country'));

Relation references

Initing a relation might need information from the main model. This is done by passing a references - options to the property. E.g.

  properties: {
    owner: {
      type: 'relation',
      model: Person,
      references: {id: 'owner_id'}
    }
  }

will read the value of owner_id property from the main model, and init relation automatically with it. So e.g. if a Model has {owner_id: 2}, owner relation will be inited with:

person = new Person({id: 2})

Validation

Validation is done by jsonschema module. Validating Models can be created by extending from ValidatingModel.

Example

var schema = {
  id: '/schemas/foo',
  type: 'object',
  properties: {
    data: {
      type: 'string'
    }
  }
};
var Foo = ValidatingModel.extend({
  type: 'foo',
  schema: schema
});
var f = new Foo({data: 'a'});
var errors = f.validate();

Will give an error, since 'data' had incorrect type.

Custom validation

If you want to make more complex validations, that jsonschema does not support, you can extend the customValidation method, see tests for more info.

Projection

Passing option {recursive: true} to toJSON, will also include relation in the JSON output. Sometimes it's useful to control which attributes are included in the JSON. This can be done with projection settings. E.g.

var projection = {
  owner: ['id', 'title'],
  removeFields: ['addresses']
};
var json = person.toJSON({recursive: true, projection: projection});

will include only 'id' & 'title' fields from the owner relation and will remove the 'addresses' relation completely from the output.

Projection options

onlyFields

onlyFields option will whitelist the given properties, thus includes only the specified properties in the JSON output.

removeFields

removeFields option will blacklist the given properties, thus removes the specified properties in the JSON output.

projection presets

You can define a projection preset in the schema, e.g.

properties: {
  ...
},
projection: {
  mini: {
    onlyFields: ['city']
  }
}

Then you can give projection options as

person.toJSON({recursive: true, projection: 'mini'})

Schema options

convert

A property can define convert function which is called when attribute is set. E.g.:

    properties: {
      id: {
        type: 'integer',
        convert: function(attribute) {
          return Number(attribute);
        }
      }, ...

Info

This project is based on https://github.com/redpie/backbone-schema

License

The MIT License

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