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Serialization class for Dynamoose. Configure properties on Model and Document as shown in TODO comments
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// TODO -- Model.serializer = new Serializer(); | |
class Serializer { | |
_serializers = {}; | |
_defaultSerializer = null; | |
add(name, options) { | |
validateName(name); | |
validateOptions(options); | |
this._serializers[name] = options; | |
if (!this._defaultSerializer) { | |
this.setDefault(name); | |
} | |
} | |
setDefault(name) { | |
validateName(name); | |
this._defaultSerializer = name; | |
} | |
remove(name) { | |
validateName(name); | |
if (this._serializers[name]) { | |
delete this._serializers[name]; | |
} | |
if (this._defaultSerializer === name) { | |
this._defaultSerializer = null; | |
} | |
} | |
// TODO -- Model.serializeMany = Model.serializer._serializeMany; | |
_serializeMany = (documentsArray = [], nameOrOptions) => { | |
documentsArray = cleanAndValidateDocumentsArray(documentsArray); | |
return documentsArray.map(doc => doc.serialize(nameOrOptions)); | |
}; | |
// TODO -- Document.serialize = nameOrOptions => this.Model.serializer._serialize(this._internalProperties, nameOrOptions); | |
_serialize = (document, nameOrOptions = this._defaultSerializer) => { | |
const inputType = typeof nameOrOptions; | |
let isArray = Array.isArray(nameOrOptions); | |
let options; | |
if (inputType === 'string') { | |
options = this._serializers[nameOrOptions]; | |
} else if (isArray || inputType === 'object') { | |
options = nameOrOptions; | |
} | |
try { | |
validateOptions(options); | |
isArray = Array.isArray(options); | |
if (isArray) { return includeHandler(document, options); } | |
let serialized = {}; | |
if(options.include){ | |
serialized = includeHandler(document, options.include, serialized); | |
} | |
if(options.exclude){ | |
if(!options.include){ | |
serialized = {...document}; | |
} | |
serialized = excludeHandler(document, options.exclude, serialized); | |
} | |
if(options.modify && typeof options.modify === 'function'){ | |
serialized = options.modify(serialized, document); | |
} | |
return serialized; | |
} catch (error) { | |
// Failing quietly and defaulting to dumping the whole object may not be safest idea, lest we expose sensitive data. | |
return { ...document }; | |
} | |
}; | |
} | |
const includeHandler = (document, includeRules, serialized = {}) => | |
includeRules.reduce((_serialized, key) => { | |
if (document.hasOwnProperty(key)) { | |
_serialized[key] = document[key]; | |
} | |
return _serialized; | |
}, serialized); | |
const excludeHandler = (document, excludeRules, serialized = {}) => | |
excludeRules.reduce((_serialized, key) => { | |
if (_serialized.hasOwnProperty(key)) { | |
delete _serialized[key]; | |
} | |
return _serialized; | |
}, serialized); | |
const validateName = name => { | |
if (!name || typeof name !== 'string') { | |
throw new Error('Field name is required and should be of type string'); | |
} | |
}; | |
const validateOptions = options => { | |
if (!options || !(Array.isArray(options) || typeof options === 'object')) { | |
throw new Error('Field options is required and should be an object or array'); | |
} | |
}; | |
const cleanAndValidateDocumentsArray = documentsArray => { | |
if (!documentsArray || !Array.isArray(documentsArray)) { | |
throw new Error('documentsArray must be an array of document objects'); | |
} | |
return documentsArray.filter(doc => typeof doc.serialize === 'function'); | |
}; | |
module.exports = Serializer; | |
/* | |
* | |
* Example Cases | |
* | |
* */ | |
// Dummy Model class | |
class Model { | |
serializer = new Serializer(); | |
serializeMany = this.serializer._serializeMany; | |
} | |
const MyModel = new Model(); | |
// Dummy Document class | |
class Document { | |
Model = MyModel; | |
_internalProperties = {}; | |
serialize = nameOrOptions => this.Model.serializer._serialize(this._internalProperties, nameOrOptions); | |
constructor(properties) { | |
Object.assign(this._internalProperties, {...properties}); | |
} | |
} | |
MyModel.serializer.add('contactOnly', ['email', 'phone']); | |
MyModel.serializer.add('excludeSecure', { exclude: ['password'] }); | |
MyModel.serializer.add('isActive', { | |
exclude: ['status', 'password'], | |
modify: (serialized, original) => { | |
serialized.isActive = original.status === 'active'; | |
return serialized; | |
} | |
}); | |
const docOne = new Document({ | |
id: 1, | |
email: 'one@example.com', | |
phone: '1234567890', | |
password: 'superSecret', | |
status: 'active' | |
}); | |
const docTwo = new Document({ | |
id: 2, | |
email: 'two@example.com', | |
phone: '9876543210', | |
password: 'moreSecret', | |
status: 'notActive' | |
}); | |
// Test array only (include) | |
console.log(docOne.serialize('contactOnly')); | |
// Test excluding only | |
console.log(docTwo.serialize('excludeSecure')); | |
// Test serializeMany with exclude and modify | |
console.log(MyModel.serializeMany([docOne, docTwo], 'isActive')); | |
// Test default serializer (should be contactOnly, the first created) | |
console.log(docOne.serialize()); | |
// Change the default serializer | |
MyModel.serializer.setDefault('isActive'); | |
// Test the new default serializer | |
console.log(docOne.serialize()); |
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