backbone-blueprint
v0.3.1
Published
Create object hierarchies based on json schema
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Backbone-blueprint
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