promised-models2

Promised Models 2

Key features

• promise based
• typed attributes
• nested models and collections
• async calculations and validation

Install

$npm install --save promised-models2

Usage

var Model = require('promises-models'),
    FashionModel = new Model.inherit({
        attributes: {
            name: Model.attributeTypes.String
        }
    }),
    model = new FashionModel({
        name: 'Kate'
    });

model.get('name'); // 'Kate'

Api reference (in progress)

Model sync methods

inherit Model.inherit(properties, [classPorperties])

Creates you own model class by extending Model. You can define attributes, instance/class method and properties. Inheritance is built over inherit.

var CountedModels = Model.inherit({
    __constructor: function () {
        this.__base.apply(this, arguments); //super
        this.attributes.index.set(this.__self._count); //static properties
        this.__self._count ++;
    },
    getIndex: function () {
        return this.get('index');
    }
}, {
    _count: 0,
    getCount: function () {
        return this._count;
    }
});

attributeTypes Model.attributeTypes

Namespace for predefined types of attributes. Supported types:

• Id - for entity id
• String
• Number
• Boolean
• List — for storing arrays
• Model — for nested models
• ModelsList — for nested collections
• Collection - another implementation of collections
• Object — serializable objects

You can extend default attribute types or create your own

var DateAttribute = Model.attributeTypes.Number.inherit({
    //..
}),
FashionModel = Model.inherit({
    attributes: {
        name: Model.attributeTypes.String,
        birthDate: DateAttribute
    }
});

Note: models.attributes will be replaced in constructor with attribute instances.

var model = new FashionModel();
model.attributes.birthDate instanceof DateAttribute; //true

set model.set(attributeName, value)

Set current value of attribute.

var model = new FashionModel();
model.set('name', 'Kate');
model.attributes.name.set('Kate');
model.set({
    name: 'Kate',
    birthDate: new Date(1974, 1, 16)
});

Note: setting null is equivalent to call .unset()

get model.get(attributeName)

Get current value of attribute.

var model = new FashionModel({
    name: 'Kate',
    birthDate: new Date(1974, 1, 16)
})
model.get('name'); //Kate
model.attributes.name.get(); //Kate
model.get('some'); //throws error as unknown attribute

toJSON model.toJSON()

Return shallow copy of model data.

Note: You can create internal attributes, which wouldn't be included to returned object.

var FashionModel = Model.inherit({
    attributes: {
        name: Model.attributeTypes.String.inherit({
            internal: true;
        }),
        sename: Model.attributeTypes.String.inherit({
            internal: true;
        }),
        fullName: Model.attributeTypes.String
    }
}),
model = new FashionModel({
    id: 1,
    name: 'Kate',
    surname: 'Moss',
    fullName: 'Kate Moss'
});
model.toJSON(); // {id: 1, fullName: 'Kate Moss'}
model.get('name'); // Kate

Note: Returned object supposed to be serializable via JSON.parse(). Due to this reason NaN and Infinity are serialized in this way:

NaN -> null
Infinity -> 'Infinity'

getId model.getId()

Returns entity id. You can declare special id attribute, which will be interpreted as entity id. If id attribute is not declared, getId returns null

var FashionModel = Model.inherit({
    attributes: {
        myId: Model.attributeTypes.Id,
        name: Model.attributeTypes.String    
    }
});

var model = new FashionModel({
    myId: 1,
    name: 'Kate'
}); 
model.getId() // 1

FashionModel = Model.inherit({
    attributes: {
        id: Model.attributeTypes.Id.inherit({
            dataType: String
        }),
        name: Model.attributeTypes.String    
    }
});

model = new FashionModel({
    id: 1,
    name: 'Kate'
}); 
model.getId() // '1'


FashionModel = Model.inherit({
    attributes: {
        name: Model.attributeTypes.String    
    }
});

var model = new FashionModel({
    id: 1,
    name: 'Kate'
}); 
model.getId() // 1

isChanged model.isChanged([branch])

Has model changed since init or last commit/save/fetch.

var FashionModel = Model.inherit({
        attributes: {
            name: Model.attributeTypes.String,
            weight: Model.attributeTypes.Number.inherit({
                default: 50
            })
        }
    }),
    model = new FashionModel({
        name: 'Kate',
        weight: 55
    });
model.isChanged(); //false
model.set('weight', 56);
model.isChanged(); //true

commit model.commit([branch])

Cache current model state

var model = new FashionModel();
model.set({
    name: 'Kate',
    weight: 55
});
model.isChanged();//true
model.commit();
model.isChanged();//false

revert model.revert([branch])

Revert model state to last cashed one

var model = new FashionModel({
    name: 'Kate',
    weight: 55
});
model.set('weight', 56);
model.revert();
model.get('weight'); //55
model.isChanged(); //false

Note: You can create your own cache by passing branch param.

var RENDERED = 'RENDERED';
model.on('change', function () {
    if (model.isChanged(RENDERED)) {
        View.render();
        model.commit(RENDERED);
    }
});

getLastCommitted model.getLastCommitted([branch])

Returns model last cached state.

previous model.previous([attr])

Returns attribute attr previous value or model previous state if called without arguments.

on model.on([attributes], events, cb, [ctx])

Add event handler for one or multiple model events.

List of events:

• change – some of attributes have been changed
• change:attributeName – attributeName have been changed
• commit - some of attributes have been committed to default branch
• branch:commit - some of attributes have been committed to branch branch
• commit:attributeName - attributeName have been committed to default branch
• branch:commit:attributeName - attributeName have been committed to branch branch
• destruct – model was destructed
• calculate – async calculations started

model.on('change', this.changeHandler, this)
     .on('change:weight change:name', this.changeHandler, this);

un model.un([attributes], events, cb, [ctx])

Unsubscribe event handler from events.

//subscribe
model.on('weight name', 'change', this.changeHandler, this);

//unsubscribe
model.un('change:weight change:name', this.changeHandler, this);

destruct model.destruct()

Remove all events handlers from model and removes model from collections

isSet model.isSet(attributeName)

Returns true if attribute was set via constructor or set

var model = new FashionModel();
model.isSet('name'); //false
model.set('name', 'Kate');
model.isSet('name'); //true

unset model.unset(attributeName)

Set attribute to default value and model.isSet() === 'false'

var model = new FashionModel();
model.set('name', 'Kate');
model.unset('name');
model.isSet('name'); //false
model.get('name'); //empty string (default value)

Model async methods

validate model.validate()

Validate model attributes.

var FashionModel = Model.inherit({
        attributes: {
            name: Model.attributeTypes.String.inherit({
                validate: function () {
                    return $.get('/validateName', {
                        name: this.get()
                    }).then(function () {
                        Vow.reject('Value is Invalid!');
                    });
                }
            })
        }
    }),
    model = new FashionModel();

model.validate().fail(function (err) {
    if (err instanceof Model.ValidationError) {
        console.log('Invalid attributes:');
        err.attributes.forEach(function (attrErr) {
            console.log('Attribute "' + attrErr.attribute.name + '" error:', attrError);
        });
    } else {
        return err;
    }
}).done();

Fulfilled attribute validation promise means that attribute is valid, otherwise it's not. Model.ValidationError#attributes is array of attributes errors (Attribute.ValidationError).

Note: For Model and Collection attributes validation method is already defined. It validates nested entity and if it's not returns promise rejected with specific error contains nested errors.

If validate returns promise rejected with String this string will be used as message for Attribute.ValidationError. If with something else (besides Boolean) - rejected value will be available in Attribute.ValidationError#data.

If attribute can be validated synchronously, you can define getValidationError method. If it returns non-falsy value, validation promise will be rejected with returned value.

var FashionModel = Model.inherit({
        attributes: {
            name: Model.attributeTypes.String.inherit({
                getValidationError: function () {
                    if (this.get() !== 'validValue') {
                        return 'Value is Invalid!';
                    }
                }
            })
        }
    }),
    model = new FashionModel();
    
model.validate().fail(function (err) {
    console.log(err.attributes[0]);
});

ready model.ready()

Fulfils when all calculations over model finished.

var FashionModel = Model.inherit({
        attributes: {
            name: Model.attributeTypes.String,
            ratingIndex: Model.attributeTypes.Number.inherit({
                calculate: function () {
                    return $.get('/rating', {
                        annualFee: this.model.get('annualFee')
                    });
                }
            }),
            annualFee: Model.attributeTypes.Number
        }
    }),
    model = new FashionModel();

model.set('annualFee', 1000000);
model.ready().then(function () {
    model.get('ratingIndex');
}).done();

fetch model.fetch()

Fetch data associated with model from storage.

var FashionModel = Model.inherit({
        attributes: {
            name: Model.attributeTypes.String
        },
        storage: Model.Storage.inherit({
            find: function (model) {
                return $.get('/models', {
                    id: model.getId()
                });
            }
        })
    }),
    model = new FashionModel({id: id});

model.fetch().then(function () {
    model.get('name');
}).done();

save model.save()

var FashionModel = Model.inherit({
        attributes: {
            id: Model.attributeTypes.Id,
            name: Model.attributeTypes.String,
            weight: Model.attributeTypes.Number
        },
        storage: Model.Storage.inherit({
            insert: function (model) {
                return $.post('/models', model.toJSON()).then(function (result) {
                    return result.id;
                });
            },
            update: function (model) {
                return $.put('/models', model.toJSON());
            }
        })
    }),
    model = new FashionModel();

model.set({
    name: 'Kate',
    weight: 55
});
model.save().then(function () { //create
    model.getId(); //storage id
    model.set('weight', 56);
    return model.save(); //update
}).done()

remove model.remove()

Removes model from storage.

Model additional methods and properties

• model.isNew()
• model.isReady()
• model.trigger(event)
• model.calculate()
• model.CHANGE_BRANCH
• model.CALCULATIONS_BRANCH

These methods provided for advanced model extending. Consult source for details.

Model static methods and properties

Storage Model.Storage

Abstract class for model storage

var FashionModel = Model.inherit({
    attributes: {
        //..
    },
    storage: Model.Storage.inherit({
        //..
    })
});

Class storage Model.storage

Storage class

var SuperModel = FashionModel.inherit({
    storage: FashionModel.storage.inherit({ //extend storage from FashionModel
        //..
    })
});

Attribute Model.Attribute

Base class for model attribute

var CustomAttribute = Model.attribute.inherit({
    //..
})

Class attributes Model.attributes

Model class attributes

var SuperModel = FashionModel.inherit({
    attributes: {
        name: FashionModel.attributes.name,
        weight: FashionModel.attributes.weight.inherit({
            default: 50
        })
    }
});

Model.on([attributes], events, cb, [ctx])

Bind event on all models of class

FashionModel.on('change', this.changeHandler, this);

Model.un([attributes], events, cb, [ctx])

Unbind event on all models of class

List

Array like object returned for fields types List and ModelsList

var Podium = Model.inherit({
    attributes: {
        models: Model.attributeTypes.ModelsList(FashionModel)
    }
}),

podium = new Podium(data),
list = podium.get('models'), //instanceof List
model = list.get(0); //instanceof Model

Mutating methods

List inerits Array mutating methods: pop, push, reverse, shift, sort, splice, unshift

podium.get('models').push(new FashionModel());

list.get(index)

Get list item by index

podium.get('models').get(0);// instanceof Model

list.length()

Returns length of list

list.toArray()

Returns shallow copy of Array, wich stores List items

podium.get('models').forEach(function (model) {
    model; // instanceof Model
});

ValidationError Model.ValidationError

Error class for validation fail report

Collection

inherit Collection.inherit(properties, [classPorperties])

Creates you own collection class by extending Collection. You should define modelType property - constructor which will be used for new models. Models that are used in collections should have declared id attribute, to make getId and related methods to work correctly.

var MyCollection = Collection.inherit({
    modelType: MyModel
});

length collection.length

Number of models in collection.

at collection.at(index)

Returns model by index.

get collection.get(id)

Returns model by id.

where collection.where(conditions)

Returns models that match the conditions.

var collection = new MyCollection([{
    name: 'John',
    age: 40
}, {
    name: 'Bob',
    age: 40
},{
    name: 'Jane'
    age: 42
}]);

collection.where({age: 40}) // -> [Model.<{name: 'John', age: 40}>, Model.<{name: 'Bob', age: 40}>]

findWhere collection.findWhere(conditions)

Same as where but returns first match.

pluck collection.pluck(attr)

Picks one attribute from each model in collection and return array of these attributes.

var collection = new MyCollection([{
    name: 'John',
    age: 40
}, {
    name: 'Bob',
    age: 40
},{
    name: 'Jane'
    age: 42
}]);

collection.pluck('name') // -> ['John', 'Bob', 'Jane']

add collection.add(models, [options])

Adds new model(s) to collection. models can be an object or instance of Model or array of objects or models. Triggers add event.

options

• options.at - position where model(s) should be inserted. By default model adds to end of colleciton

remove collection.remove(models)

Removes models from collection. models can be an instance of Model or array of models. Triggers remove event.

Note: When model removes via model.remove() it will be removed from collection

set collection.set(models)

Removes all models in collection and adds new models

Other methods

Collection implements some array methods: forEach, some, every, filter, map, reduce, find. Also collection proxies methods to models: isChanged, commit, revert, toJSON.

Model events

All model events such as change, change:attribute, calculate, commit, commit:attribute also wil be triggered on collection

run tests

$ npm test