Advanced strongly-typed JavaScript object.
npm install objectschema!Build Status  
> Advanced strongly-typed JavaScript object.
This is a light weight open source package for the server and browser (using module bundler). The source code is available on GitHub where you can also find our issue tracker.
* Simple and intuitive API
* TypeScript ready
* Field type casting
* Custom field data types
* Field dynamic default value
* Field dynamic fake value
* Field value transformation with getter and setter
* Document serialization and filtering
* Document nesting with support for self referencing
* Change tracking, data commits and rollbacks
* Advanced field validation
* Built-in and custom validators
* Contextable.js: Simple, unopinionated and minimalist framework for creating context objects with support for unopinionated ORM, object schemas, type casting, validation and error handling and more.
* Validatable.js: A library for synchronous and asynchronous validation.
* Handleable.js: A library for synchronous and asynchronous error handling.
* Typeable.js: A library for checking and casting types.
Run the command below to install the package.
``
$ npm install --save objectschema
This package uses promises thus you need to use Promise polyfill when promises are not supported.
// TODO
This package provides two core classes:
* Document represents strongly-typed data object with fields.Field
* represents a document property.
It's all about creating models.
> We will be using TypeScript for code examples for the rest of the docs. If you haven't picked it up, you should!
Creating a model is pretty straightforward. Just define a class which extends from Document.
`js
import {Document} from 'objectschema';
class User extends Document { // User model
public name: string; // class property
public constructor (data = {}, options = {}) {
super(data, options);
this.defineField('name'); // field definition for class property name
this.populate(data); // populating document
}
}
Now, you can use it like this:
`js
let user = new User({
name: 'John Smith'
});
console.log('User Name:', user.name); // => 'John Smith'
`
###
Defining models.
`js
class User extends Document {}
class Context extends Document { // Application context
public constructor () {
super();
this.defineModel(User); // defines a new class which extends User
}
public echo () {
return Hello World;`
}
}
Usage example:
`js`
let context = new Context();
let user = new context.User(); // new instance of context-aware user model
console.log(user.context.echo()); // how you would access the context from an instance method
console.log(User.context.echo()); // how you would access the context from a static method
`js
import {Document} from 'objectschema';
import {MongoClient} from 'mongodb';
class Context extends Document { // Application context
public settings: Object; // application settings
public constructor (settings = {}, options = {}) {
super(null, options);
this.settings = Object.freeze(settings); // storing application settings
}
}
`
`js
class Context extends Document { // Application context
public db: string; // class property
public constructor (settings = {}, options = {}) {
...
this.mongo = null; // initializing variable for MongoDB connection
}
public async connect (): this {
this.mongo = await MongoClient.connect(this.settings.mongo); // connecting to MongoDB
}
public async disconnect (): this {
await this.mongo.close(); // closing MongoDB connection
this.mongo = null;
}
}
`js`
let ctx = new Context();
ctx.connect(); // application started
This package consists of two core classes:
* Document represents strongly-typed data object with fields.Field
* represents a document property.
This package uses typeable.js for data type casting. Many common data types and array types are supported, but we can also use custom types. Please check package's website for a list of supported types and further information.
Validation is handled by validatable.js. The package provides many built-in validators, allows adding custom validators and overriding existing ones. When a document is created all validators share field's context thus we can write context-aware checks. Please see package's website for details.
A document is an advanced strongly-typed JavaScript object where properties are instances of the Field class.
Document(data, {parent})
> Strongly-typed JavaScript object.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| data | Object | No | - | Initial data object.
| parent | Document | No | - | Parent document instance (for nesting).
`js
class Model extends Document {
constructor (data, options) {
super(data, options);
this.defineField('name', {
type: 'String', // field type casting
get (v) { return v }, // custom getter
set (v) { return v }, // custom setter
validate: [ // value validations
{ // validator recipe (check validatable.js for more)
validator: 'presence', // validator name
message: 'must be present' // error message
}
],
defaultValue: 'Noname', // field default value (value or function)
fakeValue: 'Noname', // field fake value (value or function)
});
this.populate(data);
this.commit();
}
}
`
#### Properties
Document.prototype.options: Object
> Document options.
Document.prototype.parent: Document
> Parent document instance.
Document.prototype.root: Document
> The first document instance in a tree of documents.
#### Methods
Document.prototype.applyErrors(errors): Document
> Deeply populates fields with the provided errors.
`js`
doc.applyErrors([
{
path: ['books', 1, 'title'], // field path
errors: [
{
validator: 'presence',
message: 'is required',
code: 422
}
]
}
]);
Document.prototype.clear(): Document
> Sets all document fields to null.
Document.prototype.clone(): Document
> Returns a new Document instance which is the exact copy of the original.
Document.prototype.collect(handler): Array
> Scrolls through document fields and collects results.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| handler | Function | Yes | - | A handler method which is executed for each field.
Document.prototype.collectErrors(): Array
> Returns a list of errors for all the fields ({path, errors}[]).
`js`
doc.collectErrors(); // => {path: ['name'], errors: [{validator: 'absence', message: 'must be blank', code: 422}]}
Document.prototype.commit(): Document
> Sets initial value of each document field to the current value of a field. This is how field change tracking is restarted.
Document.prototype.defineField(name, {type, get, set, defaultValue, fakeValue, validate}): Void
> Defines a new document property.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| name | String | Yes | - | Property name.
| type | String, Document | No | - | Data type (pass a Document to create a nested structure; check typeable.js for more).
| get | Function | No | - | Custom getter.
| set | Function | No | - | Custom setter.
| defaultValue | Any | No | - | Field default value.
| fakeValue | Any | No | - | Field fake value.
| validate | Array | No | - | List of validation recipies (check validatable.js for more).
Document.prototype.defineType(name, converter): Void
> Defines a custom data type.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| name | String | Yes | - | Type name.
| converter | Function | Yes | - | Type converter.
Document.prototype.defineValidator(name, handler): Void
> Defines a custom validator.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| name | String | Yes | - | Validator name.
| handler | Function, Promise | Yes | - | Validator handler.
Document.prototype.equals(value): Boolean
> Returns true when the provided value represents an object with the same fields as the document itself.
Document.prototype.failFast(fail): Void
> Configures validator to stop field validation on the first error.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| fail | Boolean | No | false | Stops field validation on the first error when set to true.
Document.prototype.fake(): Document
> Sets each document field to its fake value if a fake value generator is registered, otherwise the default value is used.
Document.prototype.filter(handler): Object
> Converts a document into serialized data object with only the keys that pass the test.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| handler | Function | Yes | - | A function to test each key value. If the function returns true then the key is included in the returned object.
Document.prototype.flatten(): Array
> Converts the document into an array of fields.
Document.prototype.getField(...keys): Field
> Returns a class instance of a field at path.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| keys | Array | Yes | - | Path to a field (e.g. ['book', 0, 'title']).
Document.prototype.hasErrors(): Boolean
> Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.
Document.prototype.hasField(...keys): Boolean
> Returns true when a field path exists.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| keys | Array | Yes | - | Path to a field (e.g. ['book', 0, 'title']).
Document.prototype.isChanged(): Boolean
> Returns true if at least one document field has been changed.
Document.prototype.isNested(): Boolean
> Returns true if nested fields exist.
Document.prototype.isValid(): Boolean
> Returns true when all document fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.
Document.prototype.invalidate(): Document
> Clears errors on all fields.
Document.prototype.populate(data): Document
> Applies data to a document.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| data | Object | Yes | - | Data object.
Document.prototype.reset(): Document
> Sets each document field to its default value.
Document.prototype.rollback(): Document
> Sets each document field to its initial value (last committed value). This is how you can discharge document changes.
Document.prototype.scroll(handler): Integer
> Scrolls through document fields and executes a handler on each field.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| handler | Function | Yes | - | A handler method which is executed for each field.
Document.prototype.serialize(): Object
> Converts a document into serialized data object.
Document.prototype.validate({quiet}): Promise(Document)
> Validates document fields and throws an error if not all fields are valid unless the quiet is set to true.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| quiet | Boolean | No | false | When set to true, a validation error is thrown.
`jse
try {
await doc.validate(); // throws a validation error when invalid fields exist
}
catch (e) {
// is a 422 validation error`
}
Every document field is an instance of the Field class.
Field({type, get, set, defaultValue, fakeValue, validate}, {owner, validators, failFast})
> A document field.
| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| type | String, Document | No | - | Data type (pass a Document to create a nested structure; check typeable.js for more).
| get | Function | No | - | Custom getter.
| set | Function | No | - | Custom setter.
| defaultValue | Any | No | - | Field default value.
| fakeValue | Any | No | - | Field fake value.
| validate | Array | No | - | List of validation recipies (check validatable.js for more).
| owner | Document | No | - | An instance of a Document which owns the field.
| validators | Object | No | - | Custom validators (check validatable.js for more)
| failFast | Boolean | No | false | Stops validation on the first error when set to true.
#### Properties
Field.prototype.defaultValue: Any
> A getter which returns the default field value.
Field.prototype.errors: Object[];
> List of field errors (sets the validate method).
Field.prototype.fakeValue: Any
> A getter which returns a fake field value.
Field.prototype.initialValue: Any
> A getter which returns the last commited field value.
Field.prototype.options: Object
> A getter which returns field options.
Field.prototype.owner: Document
> A getter which returns a reference to a Document instance on which the field is defined.
Field.prototype.recipe: Object
> A getter which returns a field recipe object.
Field.prototype.type: Any
> A getter which returns field type (set to Document for a nested structure).
Field.prototype.value: Any
> Field current value (the actula document's property).
#### Methods
Field.prototype.clear(): Field
> Sets field and related sub fields to null.
Field.prototype.commit(): Field
> Sets initial value to the current value. This is how field change tracking is restarted.
Field.prototype.equals(value): Boolean
> Returns true when the provided value represents an object that looks the same.
Field.prototype.fake(): Field
> Sets field to a generated fake value.
Field.prototype.hasErrors(): Boolean
> Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.
Field.prototype.isChanged(): Boolean
> Returns true if the field or at least one sub field have been changed.
Field.prototype.isNested(): Boolean
> Returns true if the field is a nested document.
Field.prototype.isValid(): Boolean
> Returns true if the field and all sub fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.
Field.prototype.invalidate(): Field
> Clears the errors field on all fields (the reverse of validate()).
Field.prototype.reset(): Field
> Sets the field to its default value.
Field.prototype.rollback(): Field
> Sets the field to its initial value (last committed value). This is how you can discharge field's changes.
Field.prototype.validate(): Promise(Field)
> Validates the value and populates the errors property with errors.
`
Copyright (c) 2016 Kristijan Sedlak
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
``