#backbone-forms

A flexible, customisable form framework for Backbone.JS applications.

• Simple schema definition to auto-generate forms
• Validation
• Nested forms
• Advanced and custom editors (e.g. NestedModel, List, Date, DateTime)
• Custom HTML templates

###Example

var User = Backbone.Model.extend({
    schema: {
        title:      { type: 'Select', options: ['Mr', 'Mrs', 'Ms'] },
        name:       'Text',
        email:      { validators: ['required', 'email'] },
        birthday:   'Date',
        password:   'Password',
        address:    { type: 'NestedModel', model: Address },
        notes:      { type: 'List', listType: 'Text' }
    }
});

var user = new User();

var form = new Backbone.Form({
    model: user
}).render();

$('body').append(form.el);

###Live editable demos

• User form
• Form with Bootstrap templates and an Object list
• Update form elements based on user input

##Guide

###Table of Contents:

• Installation
• Usage
• Backbone.Form
• Schema Definition
  • Text
  • Checkboxes
  • Select
  • Radio
  • Object
  • NestedModel
  • Date
  • DateTime
  • List
• Validation
• Customising templates
• More
  • Editors without forms
  • Using nested fields
  • Custom editors
  • Help
  • Changelog

##Installation

Dependencies:

• Backbone 0.9.2

Include backbone-forms.js and backbone-forms.css:

<script src="backbone-forms/distribution/backbone-forms.min.js"></script>
<link href="backbone-forms/distribution/templates/default.css" rel="stylesheet" />

Optionally, you can include the extra editors, for example the List editor:

<script src="backbone-forms/distribution/editors/list.min.js"></script>

To use a custom template pack, e.g. Bootstrap, include the relevants file after backbone-forms.js. You can remove templates/default.css and replace it with templates/bootstrap.css.

<script src="backbone-forms/distribution/templates/bootstrap.js"></script>
<link href="backbone-forms/distribution/templates/bootstrap.css" rel="stylesheet" />

If you use Backbone with node.js, you can just require('backbone-forms'); in your index file.

Note there is also a distribution file for RequireJS / AMD.

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##Usage

Define a schema attribute on your Backbone models. The schema keys should match the attributes that get set on the model. type defaults to Text. When you don't need to specify any options you can use the shorthand by passing the editor name as a string. See schema definition for more information.

var User = Backbone.Model.extend({
    schema: {
        title:      { type: 'Select', options: ['Mr', 'Mrs', 'Ms'] },
        name:       'Text',
        email:      { validators: ['required', 'email'] },
        birthday:   'Date',
        password:   'Password',
        address:    { type: 'NestedModel', model: Address },
        notes:      { type: 'List', listType: 'Text' }
    }
});

var user = new User();

var form = new Backbone.Form({
    model: user
}).render();

$('body').append(form.el);

Once the user is done with the form, call form.commit() to apply the updated values to the model. If there are validation errors they will be returned. See validation for more information.

var errors = form.commit();

To update a field after the form has been rendered, use form.setValue:

model.on('change:name', function(model, name) {
    form.setValue({ name: name });
});

###Usage without models

You can create a form without tying it to a model. For example, to create a form for a simple object of data:

var form = new Backbone.Form({
    //Data to populate the form with
    data: {
      id: 123,
      name: 'Rod Kimble',
      password: 'cool beans'
    },
    
    //Schema
    schema: {
        id:         'Number',
        name:       'Text',
        password:   'Password'
    }
}).render();

Then instead of form.commit(), do:

var data = form.getValue(); //Returns object with new form values

###Initial data If a form has a model attached to it, the initial values are taken from the model's defaults. Otherwise, you may pass default values using the schema.data.

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##Backbone.Form

###Options

• model

  The model to tie the form to. Calling form.commit() will update the model with new values.

• data

  If not using the model option, pass a native object through the data option. Then use form.getValue() to get the new values.

• schema

  The schema to use to create the form. Pass it in if you don't want to store the schema on the model, or to override the model schema.

• fieldsets

  An array of fieldsets descriptions. A fieldset is either a list of field names, or an object with legend and fields attributes. The legend will be inserted at the top of the fieldset inside a <legend> tag; the list of fields will be treated as fields is below. fieldsets takes priority over fields.

• fields

  An array of field names (keys). Only the fields defined here will be added to the form. You can also use this to re-order the fields.

• idPrefix

  A string that will be prefixed to the form DOM element IDs. Useful if you will have multiple forms on the same page. E.g. idPrefix: 'user-' will result in IDs like 'user-name', 'user-email', etc.

  If not defined, the model's CID will be used as a prefix to avoid conflicts when there are multiple instances of the form on the page. To override this behaviour, pass a null value to idPrefix.

• template

  The template name to use for generating the form. E.g.:

    Backbone.Form.setTemplates({
        customForm: '<form class="custom-form">{{fieldsets}}</form>'
    });
  
    var form = new Backbone.Form({
        model: user,
        template: 'customForm'
    });
  

###Events

Backbone.Form fires the following events:

• change

  This event is triggered whenever something happens that affects the result of form.getValue().

• focus

  This event is triggered whenever this form gains focus, i.e. when the input of an editor within this form becomes the document.activeElement.

• blur

  This event is triggered whenever this form loses focus, i.e. when the input of an editor within this form stops being the document.activeElement.

• <key>:<event>

  Events fired by editors within this form will bubble up and be fired as <key>:<event>.

    form.on('title:change', function(form, titleEditor) { 
        console.log('Title changed to "' + titleEditor.getValue() + '".');
    });
  

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##Schema definition

The schema defined on your model can be the schema object itself, or a function that returns a schema object. This can be useful if you're referencing variables that haven't been initialized yet.

The following default editors are included:

• Text
• Number
• Password
• TextArea
• Checkbox
• Checkboxes
• Hidden
• Select
• Radio
• Object
• NestedModel
• Date
• DateTime
• List An editable list of items (included in a separate file: distribution/editors/list.min.js)

The old jQuery editors are still included but may be moved to another repository:

• jqueryui.List
• jqueryui.Date (uses the jQuery UI popup datepicker)
• jqueryui.DateTime

###Main attributes

For each field definition in the schema you can use the following optional attributes:

• type

  The editor to use in the field. Can be a string for any editor that has been added to Backbone.Form.editors, such as the built-in editors (e.g. { type: 'TextArea' }), or can be a constructor function for a custom editor (e.g. : { type: MyEditor }).

  If not defined, defaults to 'Text'.

• title

  Defines the text that appears in a form field's <label>. If not defined, defaults to a formatted version of the camelCased field key. E.g. firstName becomes First Name. This behaviour can be changed by assigning your own function to Backbone.Form.helpers.keyToTitle.

• validators

  A list of validators. See Validation for more information

• help

  Help text to add next to the editor.

• editorClass

  String of CSS class name(s) to add to the editor

• editorAttrs

  A map of attributes to add to the editor, e.g. { maxlength: 30, title: 'Tooltip help' }

• fieldClass

  String of CSS class name(s) to add to the field

• fieldAttrs

  A map of attributes to add to the field, e.g. { style: 'background: red', title: 'Tooltip help' }

• template

  Name of the template to use for this field. See Customising templates for more information.

###Main events

Every editor fires the following events:

• change

  This event is triggered whenever something happens that affects the result of editor.getValue().

• focus

  This event is triggered whenever this editor gains focus, i.e. when an input within this editor becomes the document.activeElement.

• blur

  This event is triggered whenever this editor loses focus, i.e. when an input within this editor stops being the document.activeElement.

Besides these three, editors can implement custom events, which are described below.

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##Text

Creates a normal text input.

• dataType

  Changes the type="text" attribute. Used for HTML5 form inputs such as url, tel, email. When viewing on a mobile device e.g. iOS, this will change the type of keyboard that is opened. For example, tel opens a numeric keypad.

##Select

Creates and populates a <select> element.

• options

  Options to populate the <select>.

  Can be either:

  • String of HTML <option>s
  • Array of strings/numbers
  • Array of objects in the form { val: 123, label: 'Text' }
  • A Backbone collection
  • A function that calls back with one of the above

  Backbone collection notes

  If using a Backbone collection as the options attribute, models in the collection must implement a toString() method. This populates the label of the <option>. The ID of the model populates the value attribute.

  If there are no models in the collection, it will be fetch()ed.

####Methods

• setOptions()

  Update the options in the select. Accepts any of the types that can be set in the schema options

####Examples

var schema = {
    country: { type: 'Select', options: new CountryCollection() }
};

var schema = {
    users: { type: 'Select', options: function(callback) {
        users = db.getUsers();
        
        callback(users);
    }}
}

##Radio

Creates and populates a list of radio inputs. Behaves the same way and has the same options as a Select.

##Checkboxes

Creates and populates a list of checkbox inputs. Behaves the same way and has the same options as a Select. To set defaults for this editor, use an array of values.

##Object

The Object editor creates an embedded child form representing a Javascript object.

###Attributes

• subSchema

  A schema object which defines the field schema for each attribute in the object

###Events

• <key>:<event>

  Events fired by editors within this Object editor will bubble up and be fired as <key>:<event>.

####Examples

var schema = {
    address: { type: 'Object', subSchema: {
        street: {},
        zip: { type: 'Number' },
        country: { 'Select', options: countries }
    }}
};

addressEditor.on('zip:change', function(addressEditor, zipEditor) {
    console.log('Zip changed to "' + zipEditor.getValue() + '".');
});

##NestedModel

Used to embed models within models. Similar to the Object editor, but adds validation of the child form (if it is defined on the model), and keeps your schema cleaner.

###Attributes

• model

  A reference to the constructor function for your nested model. The referenced model must have it's own schema attribute

###Events

• <key>:<event>

  Events fired by editors within this NestedModel editor will bubble up and be fired as <key>:<event>.

####Examples

var schema = {
    address: { type: 'NestedModel', model: Address }
};

addressEditor.on('zip:change', function(addressEditor, zipEditor) {
    console.log('Zip changed to "' + zipEditor.getValue() + '".');
});

##Date

Creates <select>s for date, month and year.

• yearStart

  First year in the list. Default: 100 years ago

• yearEnd

  Last year in the list. Default: current year

####Extra options You can customise the way this editor behaves, throughout your app:

var editors = Backbone.Form.editors;

editors.Date.showMonthNames = false; //Defaults to true
editors.Date.monthNames = ['Jan', 'Feb', ...] //Defaults to full month names in English

##DateTime

Creates a Date editor and adds <select>s for time (hours and minutes).

• minsInterval

  Optional. Controls the numbers in the minutes dropdown. Defaults to 15, so it is populated with 0, 15, 30, and 45 minutes.

##List

Creates a list of items that can be added, removed and edited. Used to manage arrays of data.

This is a special editor which is in a separate file and must be included:

<script src="backbone-forms/distribution/editors/list.min.js" />

If using the Object or NestedModel listType, you will need to include a modal adapter on the page. Backbone.BootstrapModal is provided for this purpose. It must be included on the page:

<script src="backbone-forms/distribution/adapters/backbone.bootstrap-modal.min.js" />

This list replaces the old jQueryUI list, but may need some upgrade work. The old jQueryUI List editor is still included in a separate file.

###Attributes

• itemType

  Defines the editor that will be used for each item in the list. Similar in use to the main 'type' schema attribute. Defaults to 'Text'.

• confirmDelete

  Optional. Text to display in a delete confirmation dialog. If falsey, will not ask for confirmation.

• itemToString

  A function that returns a string representing how the object should be displayed in a list item.

  Optional, but recommended when using listType 'Object'. When listType is 'NestedModel', the model's toString() method will be used, unless a specific itemToString() function is defined on the schema.

• listTemplate

  Name of the template to hold the list. Edit if you want to customize the 'Add' button, for instance. Optional, defaults to 'list'.

• listItemTemplate

  Name of the template to hold the list item (including the remove item button).

  Optional, defaults to 'listItem'

###Events

• add

  This event is triggered when a new item is added to the list.

• remove

  This event is triggered when an existing item is removed from the list.

• item:<event>

  Events fired by any item's editor will bubble up and be fired as item:<event>.

####Examples

function userToName(user) {
    return user.firstName + ' ' + user.lastName;
}

var schema = {
    users: { type: 'List', itemType: 'Object', itemToString: userToName }
};

listEditor.on('add', function(listEditor, itemEditor) {
    console.log('User with first name "' + itemEditor.getValue().firstName + '" added.');
});

listEditor.on('item:focus', function(listEditor, itemEditor) {
    console.log('User "' + userToName(itemEditor.getValue()) + '" has been given focus.');
});

listEditor.on('item:lastName:change', function(listEditor, itemEditor, lastNameEditor) {
    console.log('Last name for user "' + itemEditor.getValue().firstName + '" changed to "' + lastNameEditor.getValue() +'".');
});

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##Validation

There are 2 levels of validation: schema validators and the regular built-in Backbone model validation. Backbone Forms will run both when either form.commit() or form.validate() are called.

###Schema validation

Validators can be defined in several ways:

• As a string - Shorthand for adding a built-in validator. You can add custom validators to this list by adding them to Backbone.Form.validators. See the source for more information.
• As an object - For adding a built-in validator with options, e.g. overriding the default error message.
• As a function - Runs a custom validation function. Each validator the following arguments: value and formValues
• As a regular expression - Runs the built-in regexp validator with a custom regular expresssion.

###Built-in validators

• required: Checks the field has been filled in
• email: Checks it is a valid email address
• url: Checks it is a valid URL
• match: Checks that the field matches another. The other field name must be set in the field option.
• regexp: Runs a regular expression. Requires the regexp option, which takes a compiled regular expression.

####Examples

var schema = {
    //Built-in validator
    name: { validators: ['required'] },
    
    //Multiple built-in validators
    email: { validators: ['required', 'email'] },
    
    //Built-in editors with options:
    password: { validators: [
        { type: 'match', field: 'passwordConfirm', message: 'Passwords must match!' }
    ] },
    
    //Regular expression
    foo: { validators: [/foo/] },
    
    //Custom function
    username: { validators: [
        function checkUsername(value, formValues) {
            var err = {
                type: 'username',
                message: 'Usernames must be at least 3 characters long'
            };
            
            if (value.length < 3) return err;
        }
    ] }
}

###Handling errors

Error messages will be added to the field's help text area, and a customisable bbf-error class will be added to the field element so it can be styled with CSS.

Validation runs when form.commit() or form.validate() are called. If validation fails, an error object is returned with the type (validator that failed) and customisable message:

//Example returned errors from form validation:
{
    name:   { type: 'required', message: 'Required' },              //Error on the name field
    email:  { type: 'email', message: 'Invalid email address' },    //Error on the email field
    _others: ['Custom model.validate() error']                      //Error from model.validate()
}

###Customising error messages

After including the Backbone Forms file, you can override the default error messages.

{{mustache}} tags are supported; they will be replaced with the options passed into the validator configuration object. {{value}} is a special tag which is passed the current field value.

Backbone.Form.validators.errMessages.required = 'Please enter a value for this field.';

Backbone.Form.validators.errMessages.match = 'This value must match the value of {{field}}';

Backbone.Form.validators.errMessages.email = '{{value}} is an invalid email address.';

You can also override the error message on a field by field basis by passing the message option in the validator config.

###Model validation

If your models have a validate() method the errors will be added to the error object. To make the most of the validation system, the method should return an error object, keyed by the field object. If an unrecognised field is added, or just a string is returned, it will be added to the _others array of errors:

var User = Backbone.Model.extend({
    validate: function(attrs) {
        var errs = {};
        
        if (usernameTaken(attrs.username)) errs.username = 'The username is taken'
        
        if !_.isEmpty(errs) return errs;
    }
})

###Schema validators Forms provide a validate method, which returns a dictionary of errors, or null. Validation is determined using the validators attribute on the schema (see above).

If you model provides a validate method, then this will be called when you call Form.validate. Forms are also validated when you call commit. See the Backbone documentation for more details on model validation.

####Example

//Schema definition:
var schema = {
    name: { validators: ['required']
}

var errors = form.commit();

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##Customising templates

Backbone-Forms comes with a few options for rendering HTML. To use another template pack, such as for Bootstrap, just include the .js file from the templates folder, after including backbone-forms.js.

You can use your own custom templates by passing your templates (in Mustache syntax) and class names into Backbone.Form.setTemplates(). See the included templates files for examples.

You can include different field templates and then use them on a field-by-field basis by passing the template option in the field schema.

####Example

var templates = {
  //field is the default template used
  field: '\
    <div>\
      <label for="{{id}}">{{title}}</label>\
      <div>{{editor}}</div> <div>{{help}}</div>\
    </div>\
  ',

  //Specify an alternate field template
  altField: '<div class="altField">{{editor}}</div>'
};

//Set the templates
Backbone.Form.setTemplates(templates, classNames);

var schema = {
  age: { type: 'Number' }, //Uses the default 'field' template
  name: { template: 'altField' } //Uses the 'altField' template
};

####Using custom variables in templates You can pass your own template data into templates by overriding the Form.Field.renderingContext method with your own locals.

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###Changing template compiler

You can use your own custom template compiler, like Handlebars by passing a reference to the function into Backbone.Form.setTemplateCompiler().

####Example

Backbone.Form.setTemplateCompiler(Handlebars.compile);

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##More ###Editors without forms

You can add editors by themselves, without being part of a form. For example:

var select = new Backbone.Form.editors.Select({
    model: user,
    key: 'country',
    options: getCountries()
}).render();

//When done, apply selection to model:
select.commit();

###Using nested fields

If you are using a schema with nested attributes (using the Object type), you may want to include only some of the nested fields in a form. This can be accomplished by using 'path' syntax as in the example below.

However, due to Backbone's lack of support for nested model attributes, getting and setting values will not work out of the box. For this to work as expected you must adapt your model's get() and set() methods to handle the path names, or simply use DeepModel which will handle paths for you automatically.

var Model = Backbone.DeepModel.extend({
    schema: {
        title: 'Text',
        author: { type: 'Object', subSchema: {
            id: 'Number',
            name: { type: 'Object', subSchema: {
                first: 'Text',
                last: 'Text'
            }}
        }}
    }
});

var form = new Backbone.Form({
    model: new Model,
    fields: ['title', 'author.id', 'author.name.last']
}).render();

The following shorthand is also valid:

var Model = Backbone.DeepModel.extend({
    schema: {
        title: 'Text',
        'author.id': 'Number',
        'author.name.first': 'Text'
    }
});

var form = new Backbone.Form({
    model: new Model
})

###Custom editors

Writing a custom editor is simple. They must extend from Backbone.Form.editors.Base.

var CustomEditor = Backbone.Form.editors.Base.extend({
    
    tagName: 'input',
    
    events: {
        'change': function() {
            // The 'change' event should be triggered whenever something happens
            // that affects the result of `this.getValue()`.
            this.trigger('change', this);
        },
        'focus': function() {
            // The 'focus' event should be triggered whenever an input within
            // this editor becomes the `document.activeElement`.
            this.trigger('focus', this);
            // This call automatically sets `this.hasFocus` to `true`.
        },
        'blur': function() {
            // The 'blur' event should be triggered whenever an input within
            // this editor stops being the `document.activeElement`.
            this.trigger('blur', this);
            // This call automatically sets `this.hasFocus` to `false`.
        }
    },
    
    initialize: function(options) {
        // Call parent constructor
        Backbone.Form.editors.Base.prototype.initialize.call(this, options);
        
        // Custom setup code.
        if (this.schema.customParam) this.doSomething();
    },
    
    render: function() {
        this.setValue(this.value);
        
        return this;
    },
    
    getValue: function() {
        return this.$el.val();
    },
    
    setValue: function(value) {
        this.$el.val(value);
    },
    
    focus: function() {
        if (this.hasFocus) return;
        
        // This method call should result in an input within this edior
        // becoming the `document.activeElement`.
        // This, in turn, should result in this editor's `focus` event
        // being triggered, setting `this.hasFocus` to `true`. 
        // See above for more detail.
        this.$el.focus();
    },
    
    blur: function() {
        if (!this.hasFocus) return;

        this.$el.blur();
    }
});

Notes:

• The editor must implement getValue(), setValue(), focus() and blur() methods.
• The editor must fire change, focus and blur events.
• The original value is available through this.value.
• The field schema can be accessed via this.schema. This allows you to pass in custom parameters.

##Help & discussion

• Google Groups

##Changelog

###master

• Don't show if schema title===false (philfreo)
• Fix change event on radio editor (DominicBoettger)
• Fix model errors not being return by validate() (mutewinter)
• Setting value with setValue only from form.schema (okhomenko)
• Some smaller optimisation and fixes according to jsHint (MarcelloDiSimone)
• Add Form.setValue(key, val) option for arguments (lennym)
• Support ordering years in descending order in Date field (lennym)
• Allow the Number field type to accept decimal values (philfreo)
• Added 'backbone-forms' as a dependency to the AMD wrapper for templates. (seanparmelee)
• Allow use of required validator with checkbox fields (lennym)
• Make Form.Field template rendering context overrideable (drd)
• Fix a mismatched button element in the bootstrap.js template file. (there4)
• Fix AMD editors that must have backbone forms (philfreo)
• Skip undefined properties when setting form value from model.toJSON() (jgarbers)
• Add listItemTemplate option to list editors (philfreo)
• Fix NestedModel values being overridden by defaults (#99)
• Add Select.setOptions() method to change options on demand
• AMD improvements (see issue #77)
• Add 'change', 'focus' and 'blur' events (DouweM)
• Fix: #72 Hitting 'Enter' being focused on any text field in examples deletes nested "notes"
• Pressing enter in a list now adds a new item to the bottom of the list (Juice10)
• Customization of List Template & Tweaked default templates (philfreo)
• Fix not rendering of hidden fields (#75) (DouweM)
• DateTime editor:
  • Convert strings to dates
  • Remove built-in Date editor before removing self
• Email validator should accept "+" sign (#70)

###0.10.0

• update build scripts & package.json for jam packaging (dstendardi)
• Fields with options, such as Select, should handle 0 as value (torbjorntorbjorn)
• Update backbone.bootstrap-modal adapter
• Refactor rendering.
  • tags are now defined in the template.
  • Where a template is used, (e.g. advanced editors, field etc.), the entirety of the HTML is now defined in the template to make custom templating easier.
  • All templates must now have a main 'parent' element.
• Create new List, Date and DateTime editors that don't rely on jQuery UI.
  • You will still need to use jQuery UI editors for the calendar.
  • For list items of type Object and NestedModel you must include a modal adapter, such as the included Bootstrap Modal one. Should create one for jQuery UI.
• Improve the way dependencies are defined and module is exported for browser & CommonJS
• Add underscore dependency to AMD version
• Use buildify for building distribution files.
• Rename jQuery UI editors to jqueryui.List, jqueryui.Date, jqueryui.DateTime. These may be moved to a separate repository soon.
• Fix #65 Number editor Firefox NaN bug
• Fix bug with hidden fields (jeffutter)
• Fix AMD distribution bug (ikr)

####Required changes when upgrading:

• List editor:
  • Change 'listType' to 'itemType' in schema definition.
  • Make sure you have a modal adapter included if using Object and NestedModel itemTypes. See the List editor section.

###0.9.0

• Added ability to use a custom template compiler (geowa4)
• Added distribution files (development and minified production versions)
• Added AMD-compatible version (development and minified production versions)