-> Documentation for current/stable release: 0.6.2

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Introduction

Backbone's philosophy is for a View, the display of a Model's state, to re-render after any changes have been made to the Model. This works beautifully for simple apps, but rich apps often need to render, respond, and synchronize changes with finer granularity.

Stickit is a Backbone data binding plugin that binds Model attributes to View elements with a myriad of options for fine-tuning a rich app experience. Unlike most model binding plugins, Stickit does not require any extra markup in your html; in fact, Stickit will clean up your templates, as you will need to interpolate fewer variables (if any at all) while rendering. In Backbone style, Stickit has a simple and flexible api which plugs in nicely to a View's lifecycle.

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Usage

Similar to view.events, you can define view.bindings to map selectors to binding configurations. The following bindings configuration will bind the view.$('#title') element to the title model attribute and the view.$('#author') element to the authorName model attribute:

  bindings: {
    '#title': 'title',
    '#author': 'authorName'
  }

When the view's html is rendered, usually the last call will be to stickit. By convention, and in the following example, stickit will use view.model and the view.bindings configuration to initialize:

  render: function() {
    this.$el.html('<div id="title"/> <input id="author" type="text">');
    this.stickit();
  }

On the initial call, stickit will initialize the innerHTML of view.$('#title') with the value of the title model attribute, and will setup a one-way binding (model->view) so that any time a model change:title event is triggered, the view.$('#title') element will reflect those changes. For form elements, like view.$('#author'), stickit will configure a two-way binding (model<->view), connecting and reflecting changes in the view elements with changes in bound model attributes.

API

stickit

view.stickit(optionalModel, optionalBindingsConfig)

Uses view.bindings and view.model to setup bindings. Optionally, you can pass in a model and bindings hash. Note: you can only bind to a model once, any subsequent attempts to bind a previously bound model will unbind all stickit events, then rebind it (this gives you flexibility to re-render).

  render: function() {
    this.$el.html(/* ... */);
    // Initialize stickit with view.bindings and view.model
    this.stickit();
    // In addition to, or instead, call stickit with a different model and bindings configuration.
    this.stickit(this.otherModel, this.otherBindings);
  }

unstickit

view.unstickit(optionalModel)

Removes event bindings from all models. Optionally, a model can be passed in which will remove events for the given model and its corresponding bindings configuration only. Unbinding will be taken care of automatically in view.remove(), but if you want to unbind early, use this.

Bindings

The view.bindings is a hash of jQuery or Zepto selector keys with binding configuration values. Similar to the callback definitions configured in view.events, an actual function or a string function name may be configured.

observe

A string or array which is used to map a model attribute to a view element. If binding to observe is the only configuration needed, then it can be written in short form where the attribute name is the value of the whole binding configuration.

Note, binding to multiple model attributes using an array configuration only applies to one-way bindings (model->view), and should be paired with an onGet callback.

  bindings: {
    // Short form binding
    '#author': 'author',
    // Normal binding
    '#title': {
      observe: 'title'
    }
    // Bind to multiple model attributes
    '#header': {
      observe: ['title', 'author'],
      onGet: function(values) {
        // onGet called after title *or* author model attributes change.
        return values[0] + ', by ' + values[1];
      }
    }
  }

:el (selector)

A special selector value that binds to the view delegate (view.$el).

  tagName: 'form',
  bindings: {
    ':el': {
      observe: 'title'
      onGet: function(value) { /* ... */ }
    }
  }

onGet

A callback which returns a formatted version of the model attribute value that is passed in before setting it in the bound view element.

  bindings: {
    '#header': {
      observe: 'headerName',
      onGet: 'formatHeader'
    }
  },
  formatHeader: function(value, options) {
    return options.observe + ': ' + val;
  }

onSet

A callback which prepares a formatted version of the view value before setting it in the model.

  bindings: {
    '#author': {
      observe: 'author',
      onSet: 'addByline'
    }
  },
  addByline: function(val, options) {
    return 'by ' + val;
  }

getVal

A callback which overrides stickit's default handling for retrieving the value from the bound view element. Use onSet to format values - this is better used in handlers or when extra/different dom operations need to be handled.

  bindings: {
    '#author': {
      observe: 'author',
      getVal: function($el, event, options) { return $el.val(); }
    }
  }

update

A callback which overrides stickit's default handling for updating the value of a bound view element. Use onGet to format model values - this is better used in handlers or when extra/different dom operations need to be handled .

  bindings: {
    '#author': {
      observe: 'author',
      update: function($el, val, model, options) { $el.val(val); }
    }
  }

updateModel

A boolean value or a function that returns a boolean value which controls whether or not the model gets changes/updates from the view (model<-view). This is only relevant to form elements, as they have two-way bindings with changes that can be reflected into the model. Defaults to true.

  bindings: {
    '#title': {
      observe: 'title',
      updateModel: 'confirmFormat'
    }
  },
  confirmFormat: function(val, options) {
    // Only update the title attribute if the value starts with "by".
    return val.startsWith('by ');
  }

updateView

A boolean value or a function that returns a boolean value which controls whether or not the bound view element gets changes/updates from the model (view<-model). Defaults to true.

bindings: {
  '#title': {
    observe: 'title',
    // Any changes to the model will not be reflected to the view.
    updateView: false
  }
}

afterUpdate

Called after a value is updated in the dom.

  bindings: {
    '#warning': {
      observe: 'warningMessage',
      afterUpdate: 'highlight'
    }
  },
  highlight: function($el, val, options) {
    $el.fadeOut(500, function() { $(this).fadeIn(500); });
  }

updateMethod

Method used to update the inner value of the view element. Defaults to 'text', but 'html' may also be used to update the dom element's innerHTML.

  bindings: {
    '#header': {
      observe: 'headerName',
      updateMethod: 'html',
      onGet: function(val) { return '<div id="headerVal">' + val + '</div>'; }
    }
  }

escape

A boolean which when true escapes the model before setting it in the view - internally, gets the attribute value by calling model.escape('attribute'). This is only useful when updateMethod is "html".

  bindings: {
    '#header': {
      observe: 'headerName',
      updateMethod: 'html',
      escape: true
    }
  }

visible and visibleFn

When true, visible shows or hides the view element based on the model attribute's truthiness. visible may also be defined with a callback which should return a truthy value.

If more than the standard jQuery show/hide is required, then you can manually take control by defining visibleFn with a callback.

  bindings: {
    '#author': {
      observe: 'isDeleuze',
      visible: true
    }
  }

  bindings: {
    '#title': {
      observe: 'title',
      visible: function(val, options) { return val == 'Mille Plateaux'; }
    }
  }

  bindings: {
    '#body': {
      observe: 'isWithoutOrgans',
      visible: true,
      visibleFn: 'slideFast'
    }
  },
  slideFast: function($el, isVisible, options) {
    if (isVisible) $el.slideDown('fast');
    else $el.slideUp('fast');
  }

Form Element Bindings and Contenteditable

By default, form and contenteditable elements will be configured with two-way bindings, syncing changes in the view elements with model attributes. Optionally, one-way bindings can be configured with updateView or updateModel. With the eventsOverride, you can specify a different set of events to use for reflecting changes to the model.

The following is a list of the supported form elements, their binding details, and the default events used for binding:

• input, textarea, and contenteditable
  • element value synced with model attribute value
  • input[type=number] will update the model with a Number value
  • keyup, change, cut, and paste events are used for handling
• input[type=checkbox]
  • checked property determined by the truthiness of the model attribute or if the checkbox "value" attribute is defined, then its value is used to match against the model. If a binding selector matches multiple checkboxes then it is expected that the observed model attribute will be an array of values to match against the checkbox value attributes.
  • change event is used for handling
• input[type=radio]
  • model attribute value matched to a radio group value attribute
  • change event is used for handling
• select
  • see the selectOptions configuration
  • change event is used for handling

events

Specify a list of events which will override stickit's default events for a form element. Bound events control when the model is updated with changes in the view element.

  bindings: {
    'input#title': {
      observe: 'title',
      // Normally, stickit would bind `keyup`, `change`, `cut`, and `paste` events
      // to an input:text element. The following will override these events and only 
      // update/set the model after the input#title element is blur'ed.
      events: ['blur']
    }
  }

selectOptions

Binds an object collection, html select box, and a model attribute value. The following are configuration options for binding:

• collection: an object path of a collection relative to window or view/this, or a string function reference which returns a collection of objects. A collection should be either an array of objects or Backbone.Collection.
• labelPath: the path to the label value for select options within the collection of objects. Default value when undefined is label.
• valuePath: the path to the values for select options within the collection of objects. When an options is selected, the value that is defined for the given option is set in the model. Leave this undefined if the whole object is the value or to use the default value.

When bindings are initialized, Stickit will build the select element with the options and bindings configured.

Note: if you are using Zepto and referencing object values for your select options, like in the second example, then you will need to also include the Zepto data module.

The following example references a collection of stooges at window.app.stooges and uses the age attribute for labels and the name attribute for option values:

  window.app.stooges = [{name:'moe', age:40}, {name:'larry', age:50}, {name:'curly', age:60}];

  bindings: {
    'select#stooges': {
      observe: 'stooge',
      selectOptions: {
        // Alternatively, `this.` can be used to reference anything in the view's scope.
        // For example: `collection:'this.stooges'`` would reference `view.stooges`.
        collection: 'window.app.stooges',
        labelPath: 'age',
        valuePath: 'name'
    }
  }

The following is an example where a collection is returned by callback and the collection objects are used as option values:

  bindings: {
    'select#states': {
      observe: 'state',
      selectOptions: {
        collection: function() {
          // Prepend null or undefined for an empty select option and value.
          return [null, {id:1, data:{name:'OH'}}, {id:2, data:{name:'IN'}}];
        },
        labelPath: 'data.name'
        // Leaving `valuePath` undefined so that the collection objects are used 
        // as option values. For example, if the "OH" option was selected, then the 
        // following value would be set into the model: `model.set('state', {id:1, data:{name:'OH'}});`
    }
  }

Optgroups are supported, where the collection is formatted into an object with an opt_labels key that specifies the opt label names and order.

  bindings: {
    'select#tv-characters': {
      observe: 'character',
      selectOptions: {
        collection: function() {
          return {
            'opt_labels': ['Looney Tunes', 'Three Stooges'],
            'Looney Tunes': [{id: 1, name: 'Bugs Bunny'}, {id: 2, name: 'Donald Duck'}],
            'Three Stooges': [{id: 3, name: 'moe'}, {id: 4, name: 'larry'}, {id: 5, name: 'curly'}]
          };
        },
        labelPath: 'name',
        valuePath: 'id'
      }
    }
  }

Finally, multiselects are supported if the select element contains the [multiple="true"] attribute. By default stickit will expect that the model attribute is an array of values, but if your model has a formatted value, you can use onGet and onSet to format attribute values (this applies to any select bindings).

//
// model.get('books') returns a dash-delimited list of book ids: "1-2-4"

bindings: {
  '#books': {
    observe: 'books',
    onGet: function(val) {
      // Return an array of the ids so that stickit can match them to select options.
      return _.map(val.split('-'), Number);
    },
    onSet: function(vals) {
      // Format the array of ids into a dash-delimited String before setting.
      return vals.join('-');
    },
    selectOptions: {
      collection: 'app.books',
      labelPath: 'name',
      valuePath: 'id'
    }
  }
}

setOptions

An object which is used as the set options when setting values in the model. This is only used when binding to form elements, as their changes would update the model.

  bindings: {
    'input#name': {
      observe: 'name',
      setOptions: {silent:true}
    }
  }

Attribute and Property Bindings

attributes

Binds element attributes and properties with observed model attributes, using the following options:

• name: attribute or property name.
• observe: observes the given model attribute. If left undefined, then the main configuration observe is observed.
• onGet: formats the observed model attribute value before it is set in the matched element.

  bindings: {
    '#header': {
      attributes: [{
        name: 'class',
        observe: 'hasWings',
        onGet: 'formatWings'
      }, {
        name: 'readonly',
        observe: 'isLocked'
      }]
    }
  },
  formatWings: function(val) {
    return val ? 'has-wings' : 'no-wings';
  }

Custom Handlers

addHandler

Backbone.Stickit.addHandler(handler_s)

Adds the given handler or array of handlers to Stickit. A handler is a binding configuration, with an additional selector key, that is used to customize or override any of Stickit's default binding handling. To derive a binding configuration, the selectors are used to match against a bound element, and any matching handlers are mixed/extended in the order that they were added.

Internally, Stickit uses addHandler to add configuration for its default handling. For example, the following is the internal handler that matches against textarea elements:

Backbone.Stickit.addHandler({
  selector: 'textarea',
  events: ['keyup', 'change', 'paste', 'cut'],
  update: function($el, val) { $el.val(val); },
  getVal: function($el) { return $el.val(); }
})

Except for the selector, those keys should look familiar since they belong to the binding configuration api. If unspecified, the following keys are defaulted for handlers: updateModel:true, updateView:true, updateMethod:'text'.

By adding your own selector:'textarea' handler, you can override any or all of Stickit's default textarea handling. Since binding configurations are derived from handlers with matching selectors, another customization trick would be to add a handler that matches textareas with a specific class name. For example:

Backbone.Stickit.addHandler({
  selector: 'textarea.trim',
  getVal: function($el) { return $.trim($el.val()); }
})

With this handler in place, anytime you bind to a textarea, if the textarea contains a trim class then this handler will be mixed into the default textarea handler and getVal will be overridden.

F.A.Q.

Why Stickit?

JavaScript frameworks seem to be headed in the wrong direction - controller callbacks/directives, configuration, and special tags are being forced into the template/presentation layer. Who wants to program and debug templates?

If you are writing a custom frontend, then you're going to need to write custom JavaScript. Backbone helps you organize with a strong focus on the model, but stays the hell out of your presentation. Configuration and callbacks should only be in one place - the View/JavaScript.

Dependencies

Backbone 0.9, underscore.js, and jQuery or Zepto (with data module; see selectOptions)

License

MIT

Change Log

Master

• Added Backbone.Stickit.addHandler(), useful for defining a custom configuration for any bindings that match the handler.selector.
• Breaking Change: eventsOverride was changed to events.
• Breaking Change: removed the third param (original value) from the afterUpdate parameters.
• Breaking Change: replaced unstickModel with unstickit.
• Breaking Change: removed deprecated modelAttr from bindings api.
• Breaking Change: removed deprecated format from bindings api.
• Fixed a bug introduced in 0.6.2 where re-rendering/re-sticking wasn't unbinding view events #66.
• Added update to the bindings api which is an override for handling how the View element gets updated with Model changes.
• Added getVal to the bindings api which is an override for retrieving the value of the View element.
• Added support for passing in Backbone.Collection's into selectOptions.collection.
• Added support for referencing the view's scope with a String selectOptions.collection reference. For example: collection:'this.viewCollection'.

0.6.2

• Breaking Change: Changed the last parameter from the model attribute name to the bindings hash in most of the binding callbacks. Note the model attribute name can still be gleaned from the bindings hash - options.observe. The following are the callbacks that were affected and their parameters (options are the bindings hash):
  onGet(value, options)
onSet(value, options)
updateModel(value, options)
updateView(value, options)
afterUpdate($el, value, originalVal, options)
visible(value, options)
visibleFn($el, isVisible, options)
• Added support for handling multiple checkboxes with one binding/selector and using the value attribute, if present, for checkboxes.
• Added default values for labelPath and valuePath in selectOptions: label and value respectively.
• Refactored event registration to use $.on and $.off instead of delegating through Backbone which fixed the following bugs:
  • view.events selectors and binding selectors that are equal were overriding #49
  • view.events declared as a function was not supported #51
• Fixed some bugs and added support requirements for zepto.js; #58.
• Bug Fixes: #38, #42,

0.6.1

• Added observe in place of modelAttr (deprecated modelAttr but maintained for backward-compatibility).
• Added onGet in place of format (deprecated format but maintained for backward-compatibility).
• Added onSet binding for formatting values before setting into the model.
• Added updateModel, a boolean to control changes being reflected from view to model.
• Added updateView, a boolean to control changes being reflected from model to view.
• Added eventsOverride which can be used to specify events for form elements that update the model.
• Breaking Change: Removed manual event configuration/handling (no keyup, submit, etc, in binding configurations).
• Added support for multiselect select elements.
• Added support for optgroups within a select element.
• Bug Fixes: #29, #31

0.6.0

• Breaking Change: Removed readonly configurtion option.
• Element properties (like readonly, disabled, etc.) can be configured in attributes.
• Added custom event handling to the api - see events section in docs.
• Added support for binding multiple model attributes in modelAttr configuration.
• Added the visible and visibleFn binding configurations.
• Added support for :el selector for selecting the view delegate.
• Bug Fixes: #10, #11, #16

0.5.2

• Fix IE7/8 select options bug (issue #9)

0.5.1

• Shorthand binding for model attributes: '#selector':attrName.
• Added support for input[type=number] where values will be bound to model attributes as the Number type.
• Attribute name is passed in as the second parameter of format callbacks.
• Bug fixes: issue #1, #2, #4, #6, #8

0.5.0

• Initial release (extracted and cleaned up from the backend of cn.nytimes.com).