typescript-data-model

Data Model For Typescript

By Somefive

This library is used for created data model using Class Object based on Typescript. The data model uses decorators to decorate properties. Currently, there are two kinds of decorators: Scenario and Validator.

Installing with npm

Run npm install --save-dev typescript-data-model.

Then use import {Model, scenario, validate} from 'data-model'

Notices: since this library use decorators and metadata which are experimental, experimentalDecorators and emitDecoratorMetadata should be enabled in tsconfig.json which means you should add

"experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
"emitDecoratorMetadata": true         /* Enables experimental support for emitting type metadata for decorators. */

to your tsconfig.json file.

Sample

Sample can be found in sample/index.ts. You can also run npm run sample to compile it into sample/dist and run it.

Introduction

Model

The Model class is the base class which can be extended while used.

The property scenario indicates the current scenario of this model and the property scenarioDefaultIncluded decides whether a property should be available while there is no ScenarioFilter applied on it.

isFieldAvailable check if one specified field is available under current scenario.

load can be used to load properties if the property is available and exists in the given object.

toDocs can publish current data model to object that contains specified available fields. If no fields specified then all available fields are going to be published. The option ignoreNil will ignore the fields that has null or undefined value. It is set to be true by default. The option force will skip the availability check and this is set to false by default.

validate can validate specified available fields if validators are suppressed on them. If no fields specified then all available fields are going to be published. The option force will skip the availability check and this is set to false by default.

Watch out: Each field should be initialized in constructor otherwise when it is not defined explicitly, the validation and scenario will not work on it.

Scenario

The ScenarioFilter is composed of list of included and excluded scenarios. The defaultIncluded is set to decide whether the suppressed property is available if current scenario is neither in included list nor in excluded list.

The ScenarioName includes string and Symbol types which are the valid parameter types when creating scenarios.

For example, Model default scenario are set to be default, if default is in a property's excluded scenario list then it will be unavailable.

Scenarios can be enabled by adding @scenario(scenarioFilter) to a property. Such as

@scenario(new ScenarioFilter(false, ["passwordEnabledScenario"]))
password: string

Validation

The validation is based on interface IValidator. Validation will be used when Model call validation to check. If the property is not available then it will be skipped by the validation.

Validation can be enabled by adding @validation(iValidator) to a property. Such as

@validate(new RangeValidator(1,100))
age: number

There are several validator available in the library and you can also create you own validator just implement the IValidator interface.

RegexValidator is using RegExp to validate string. RangeValidator is using min and max value to check number in range. ArrayValidator validates arrays. It takes another validator to validate every item. The error will be displayed in object instead of array. NestedValidator validates nested Model. You can specified what fields are to be validated in nested Model. ChainValidator can chain validators. PredicateValidator takes one predicate such as lambda expression to customize the validation which is a bit simplier than implementing a new validator. NotEmptyValidator checks if string, array, object are empty or undefined.