Backbone collection - applyRecursive. To facilitate applying functions that need to traverse collection models and all their children.

backbone_collection_applyRecursive

// runs parameter function on all collection models (including children). Expects child collection to be defined in model as "nodes".
applyRecursive: function(func) {
    // takes the last given function parameter - recursion makes arguments array more complex, se need to flatten it out.
    var lastArg = _.chain(arguments).toArray().flatten().last().value();

    this.each(function(model) {
        func.call(model, func, lastArg);   // run function in context of the model.

        // if has nodes, apply function to nodes.
        if ((typeof model.nodes !== 'undefined') && (typeof model.nodes.models !== 'undefined') && (model.nodes.models.length > 0)) {
            model.nodes.applyRecursive(func, lastArg);
        }
    });
    // TODO: should trigger an event when complete to reactions. Implement internal counter for initiated functions, to find out end of recursions.
}