model

Lightweight model which supports proper dirty state and change events.

Installation

$ component install mikanda/model

Usage

var model = require('model');
var Address = model()
  .attr('street')
  .attr('zipCode')
  .attr('locality');
var User = model()
  .attr('name')
  .attr('age', Number)
  .attr('address', Address);

var user = new User({
  name: 'Mister test',
  age: '49', /* Is automatically turned into a number */
  address: { street: '...' }
});
user.on('change', function(name, value, old){

  // `name` is the keypath to the value that changed; e.g.
  //
  //   - 'address.street'
  //   - 'name'
  //   - etc.
  //
  // `value` is the new value of the attribute and `old` was the old value

});

// fires the change event
user.name = 'New name';

// fires the change event with 'address.street' as name
user.address.street = 'New street';

// to listen to the change of a specific attribute only use the following
user.on('change name', function(){

  // ...

});

model creation API

constructor Model()

Initializes a new model.

Model.attr()

Defines a new attribute.

Parameters

{String} name - Just the name of the attribute
{Object|Function|Any} opts - This can be either a function which is then handled as constructor (called with new) for each incoming value. In case of an object it is handled as an options object which supports the following options:
- preset - Acts as default value for the attribute. default: undefined
- persistent - If false this value is not included within the JSON representation of the model and doesn't affect the dirty status of the model. default: false
- compute - A function which is called as getter to the attribute. It gets passed the attribute name for which it is registered. The context of the function is the object.

model instance API

Events

change(name, value, old) - Fired on every change of the model. name is the name of the attribute which changed, value is the new value of the attribute and old is the old.
change ATTR - Fired if ATTR was changed.

constructor model([values])

Initializes the model with the given values. values is an object holding the values for the model. e.g. { name: 'My name', ... }

model.ATTR

Getter and setter for ATTR. ATTR represents the attribute-name you want to access. e.g. model.name.

...

var model = new Model({ name: 'Hans' });
console.log(model.name);  // => 'Hans'

// fires the change events
model.name = 'Peter';

model.update([values])

Update the model with the given values. Also calls constructors of the properties if defined.

model.isDirty([attrName])

Checks if the attribute at attrName is dirty. If none is given checks if the whole model is dirty.

model.resetDirty()

Resets the dirty state of the model and all submodels.

model.reset([attrName])

Resets the given attrName or all values of the model and all submodels.

model.toJSON()

Get a JSON representation of the model. Excludes all attributes declared with the option persistent: false.

Tests

Checkout the repository and run the following commands:

$ npm install
$ component install --dev
$ npm test

This will run a test server on the port 3000. Afterwards you should open your browser and navigate to http://localhost:3000.