Bookshelf fields

npm install bookshelf-fields
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Bookshelf plugin for simpler model validation and field format convertion.

What exactly it does

First of all when plugged in with call to db.plugin it (re)defines several db.Model methods:

  • validate - perform validation of model with CheckIt. It uses instance array 'validations' for field-level validation and array 'model_validations' for validating the whole model.

  • format/parse - for each field defined in model applys its format/parse method

Then when field is applyed to a model it

  • stores the itself in the models __meta.fields array

  • may add some validation rules to validations of model_validations arrays

  • defines with the same name. By default this property only calls basic set and get methods

And finally when called to enable_validation it redefines models initialize method, adding subscription to event 'saving' to perform validation.

Basic usage

First you need to require bookshelf-fields and apply exported plugin to an initialized database instance:

Fields = require 'bookshelf-fields'
db.plugin Fields.plugin

Now you are ready to add fields information to models. There are two equivalent ways to do it: with exported functions 'field', 'fields' and 'enable_validation' and with the same methods, mixed into a Function prototype. If you choose the second way you need to call Fields.pollute_function_prototype() before.

Provided helpers

  • plugin - method that mixes Fields functionality into a Bookshelf Model

    db.plugin Fields.plugin

  • enable_validation(model) - actually turn on validation for a specified model


  • field(model, field_class, name, options) - add field to a model

    field(User, Fields.StringField, 'username', {max_length: 64})

  • fields(model, field_definitions...) - add a bunch of fields to a model. field_definitions is one or more arrays [field_class, name, options]

  • pollute_function_prototype() - add methods enable_validation, field and fields to a Function prototype. Those methods have the same signature as a same-named functions excluding first 'model' parameter.

  • cleanup_function_prototype() - remove methods added in pollute_function_prototype


Common options

  • required: boolean - field must be provided and not empty
  • not_null: boolean - field must not be null
  • choices: [array or hash] - field must have one of provided values

    choices_ may be defined as an array (['foo', 'bar']) or as a hash ({foo: 'foo description', bar: bar description'}). If hash used then field value is compared with hash keys.

  • comparator: function - used with choices to provide custom equality checker.

    Useful if fields value is an object and simple '==' is not adequate.


  • min_length | minLength: integer
  • max_length | maxLength: integer


StringField with simple check that value looks like a email address


Does no any validation - use IntField or FloatField instead!

  • gt | greater_than | greaterThan: integer
  • gte | greater_than_equal_to | greaterThanEqualTo | min: integer
  • lt | less_than | lessThan: integer
  • lte | less_than_equal_to | lessThanEqualTo | max: integer


NumberField checked to be Integer. Applys parseInt when loaded.


NumberField checked to be Float. Applys parseFloat when loaded.


Casts value to Boolean on parse and format.


Validates that value is a Date or a string than can be parsed as Date. Converts value to Date on parse and format.


DateTimeField with stripped Time part.


Validates that value is object or a valid JSON string. Parses string from JSON when loaded and stringifies to JSON when formatted.

Add custom behaviour

You can add extra validations to models arrays validations and model_validations. Just make sure that you doesn't throw away validations added by fields. If you redefine initialize method call parent initialize or manage calling validate method on model saving. You can also redefine validate method.



Bookshelf = require 'bookshelf'
Fields = require 'bookshelf-fields'

db = Bookshelf.initialize
    client: 'sqlite'
        filename: './test.db'

db.plugin Fields.plugin


class User extends db.Model
    tableName: 'users'

    @field Fields.StringField, 'username', max_length: 32
    @field Fields.EmailField, 'email'


new User(username: 'bogus', email: '').save()
    .otherwise (errors) ->
        console.log errors.toJSON()
        throw errors
    .then (user) ->
        console.log user.username # username is a property, calling @get('username') in getter
        console.log = 'invalid-email' # simply calliong @set('email', 'invalid-email') in setter (errors) ->
            console.log errors.toJSON() # { email: 'The email must contain a valid email address' }


Bookshelf = require('bookshelf');
Fields = require('bookshelf-fields');

var db = Bookshelf.initialize({
    client: 'sqlite',
    connection: { filename: './test.db' }


User = db.Model.extend({ tableName: 'users' });

    [Fields.StringField, 'username', {max_length: 32}],
    [Fields.EmailField, 'email']

new User({username: 'bogus', email: ''}).save()
    .otherwise(function(errors) {
        throw errors;
    }).then(function(user) {
        console.log(user.username); // username is a property, calling @get('username') in getter
        console.log(; = 'invalid-email'; // simply calliong @set('email', 'invalid-email') in setter {
            console.log(errors.toJSON()); // { email: 'The email must contain a valid email address' }
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