Tiny JavaScript data-binder using Object.observe.

DataBind.js

var DataBind = function(el, model) {
    this.el = el;
    this.model = model;

    // Bind event handlers to this.
    this._updateModel = this._updateModel.bind(this);
    this._updateEl    = this._updateEl.bind(this);
    
    Object.observe(model, this._updateEl);
    this.el.addEventListener('keyup', this._updateModel, false);
};

// Update element value when model attribute changes.
DataBind.prototype._updateEl = function(change) {
    var val, name;
    
    for(var i = 0; i < change.length; i++) {
        name = change[i].name;
        if(this.el.dataset.bind === name) {
            val = change[i].object[name];
        
            this.el.value = val;
            this.el.innerHTML = val;
        }
    }
};

// Update model when element value changes.
DataBind.prototype._updateModel = function(change) {
    var attr = change.target.dataset.bind;
    this.model[attr] = change.target.value;
};

// Destroy current data binding.
DataBind.prototype.destroy = function() {
    this.el.removeEventListener('keyup', this._updateModel, false);
    Object.unobserve(this.model, this._updateEl);
};