IPython/html/static/widgets/js/widget_button.js

// Copyright (c) IPython Development Team.
// Distributed under the terms of the Modified BSD License.

define([
    "widgets/js/widget",
], function(widget){

    var ButtonView = widget.DOMWidgetView.extend({
        render : function(){
            // Called when view is rendered.
            this.setElement($("<button />")
                .addClass('btn btn-default'));

            this.update(); // Set defaults.
        },
        
        update : function(){
            // Update the contents of this view
            //
            // Called when the model is changed.  The model may have been 
            // changed by another view or by a state update from the back-end.
            var description = this.model.get('description');
            if (description.length === 0) {
                this.$el.html("&nbsp;"); // Preserve button height
            } else {
                this.$el.text(description);
            }
            
            if (this.model.get('disabled')) {
                this.$el.attr('disabled','disabled');
            } else {
                this.$el.removeAttr('disabled');
            }

            return ButtonView.__super__.update.apply(this);
        },

        events: {
            // Dictionary of events and their handlers.
            'click': '_handle_click',
        },
        
        _handle_click: function(){
            // Handles when the button is clicked.
            this.send({event: 'click'});
        },
    });

    return {
        'ButtonView': ButtonView,
    };
});