如何在执行路由方法之前运行"中间件"功能？

Question

假设我有一个骨干路由器,如:

routes:
  ""                          : "homepage"
  "catalog/:id"               : "catalogPage"
  "catalog/:id/products/:id2" : "productPage"

homepage   :           -> doStuff()
catalogPage: (id)      -> doOtherStuff()
productPage: (id, id2) -> doEvenMoreStuff()

和功能:

executeBefore = -> console.log("hello")

如果我希望每次调用路由并在相应的路由方法之前调用并执行executeBefore,除了在每个路由方法的开头插入对executeBefore的调用之外,还有一种简单的方法吗？

Answer 1

您可以覆盖route路由器类中的功能以拦截路由调用:

var Router = Backbone.Router.extend({
    routes: {
        "" : "homepage",
        "catalog/:id" : "catalogPage"
    },

    route: function(route, name, callback) {
        var router = this;
        if (!callback) callback = this[name];

        var f = function() {
            console.log('route before', route);
            callback.apply(router, arguments);
            console.log('route after', route);
        };
        return Backbone.Router.prototype.route.call(this, route, name, f);
    },

    homepage: function() {
        console.log("homepage");
    },
    catalogPage: function(id) {
        console.log("catalogPage "+id);
    }
});

var r = new Router();
Backbone.history.start();

和演示http://jsfiddle.net/nikoshr/EdLzh/

Answer 2

自2014年2月13日起，您可以使用router.execute(callback, args, name)（http://backbonejs.org/#Router-execute）执行此操作。

所以您的拦截器将看起来像这样

routes: {
    '': 'homepage',
    'catalog/:id': 'catalogPage',
    'catalog/:id/products/:id2': 'productPage'
},
execute: function(callback, args, name) {
    // Do your stuff here
    executeBefore();

    if (callback) callback.apply(this, args);
}

https://github.com/jashkenas/backbone/commit/791033dc1aab53e9e5c9366f64a854224f851231