I'm making a form with rich text in it. I have TinyMCE for that, Backbone controls the logic and underscore is used for templating.

I can't find if there's a way to bind a Backbone model to the TinyMCE value?

Something like:

var backboneModel = new BackBobeModel();
tinymce.init({ 
    selector:'#rich-text',
    'data-object': backboneModel.richText
});

As far as I know, TinyMCE doesn't bind automatically with Backbone. So I made a simple reusable TextArea component.

It's made from a Backbone View which init its own root <textarea> element as a TinyMCE instance and binds itself into its Change event.

TinyMCE Backbone component

var TextArea = Backbone.View.extend({
    tagName: 'textarea',
    initialize: function(options) {
        // set the default options
        options = this.options = _.extend({
            attribute: 'value',
            format: 'raw'
        }, options);

        // initialize a default model if not provided
        if (!this.model) this.model = new Backbone.Model();
        if (!this.getValue()) this.setValue('');

        this.listenTo(this.model, 'change:' + options.attribute, this.onModelChange);
    },
    render: function() {
        this.$el.html(this.getValue());
        tinymce.init({
            target: this.el,
            init_instance_callback: this.onEditorInit.bind(this)
        });
        return this;
    },

    // simple accessors
    getValue: function() {
        return this.model.get(this.options.attribute) || '';
    },
    setValue: function(value, options) {
        return this.model.set(this.options.attribute, value, options);
    },
    // event handlers
    onEditorInit: function(editor) {
        editor.on('Change', this.onTextChange.bind(this));
        this.editor = editor;
    },
    onTextChange: function(e) {
        this.setValue(this.editor.getContent());
    },
    onModelChange: function(model, value, options) {
        if (!this.editor) return;
        this.editor.setContent(value, { format: this.options.format });
    }
});

Use it as-is

You can use it without a model, and it will create its own model to keep track of the data.

var component = new TextArea({ content: "initial content" });

It's possible to retrieve the data or even listen to the component's model.

component.getValue();
// or use events:
Backbone.listenTo(component.model, 'change:value', function(model, value, options) {
    // use the new value
});

Use it with a custom model

Say you have a custom model with arbitrary attributes.

var car = new CarModel({ 
    make: "mazda", 
    description: "This is a car"
    // ...
});

Just pass it to the component, defining which attribute it should use to update the model.

var component = new TextArea({ 
    model: car, 
    // 
    attribute: 'description'
});

The same initial model instance description attribute will now be auto-updated anytime a user types in the TinyMCE box.

Backbone.listenTo(car , 'change:description', function(model, value, options) {
    console.log("Car description changed:", value);
});