var CollectionView = Backbone.View.extend({
    appendItem: function() {},
    updateItem: function() {},
    removeItem: function() {},
    clear: function() {},
    repopulate: function() {
        this.clear();
        this.collection.each(this.appendItem, this);
    },
    bindCollection: function() {
        this.repopulate();
        
        this.collection
            .on('add', this.appendItem, this)
            .on('change', this.updateItem, this)
            .on('remove', this.removeItem, this)
            .on('reset', this.repopulate, this);
    },
    unbindCollection: function() {
        this.collection.off(null, null, this);
    },
    compileTemplates: function(templates) {
        this.templates = {};
        
        _.each(templates, function(template, name) {
            this.templates[name] = _.template(template);
        }, this);
    }
});
var Displayer = Backbone.View.extend({
    render: function(text) {
        this.$el.text(text);
        return this;
    }
});
var CollectionCounterView = CollectionView.extend({
    initialize: function(options) {
        if ('plurals' in options) {
            this.makeTitle = function(n) {
                return n + ' ' + options.plurals[n == 1 ? 0 : 1];
            };
        }
        this.bindCollection();
    },
    appendItem: function() {
        this.repopulate();
    },
    removeItem: function() {
        this.repopulate();
    },
    repopulate: function() {
        this.$el.html(this.makeTitle(this.collection.models.length));
    },
    makeTitle: function(n) {
        return n;
    }
});