我需要在服务器的所有响应中捕获可能的登录页面,因此我全局覆盖了Backbone.sync,因此我可以在传递之前检查所有错误.
Backbone.originalSync = Backbone.sync;
Backbone.sync = function (method,model,options) {
var originalSuccess,originalError;
console.log("sync override...");
// remember original success so we can call it if user logs in successfully
originalSuccess = options.success;
// proxy the error callback to first check if we get a login page back
originalError = options.error;
options.error = function (model,xhr,options) {
if (xhr.status === 200 && xhr.responseText === "") {
// parse error from empty response (jq1.9 invalid json,ok)
originalSuccess(model,options);
} else {
console.log("Sync error " + statusTxt + "," + thrown.message);
if (xhr.status === 200 || xhr.status === 302 || xhr.status === 0) {
// login page returned instead of json...
// open a new window with relogon.html to trigger a new login
window.showModalDialog("../relogon.html");
} else {
// normal error,pass along
if (originalError) {
originalError(model,options);
}
}
}
};
// call the original sync
Backbone.originalSync(method,options);
};
当从0.9.9变为1.0时,这种情况很糟糕.看起来原始的Backbone.sync以不同的方式包装其错误处理程序,导致我的错误处理程序首先被调用,带有jquery xhr签名.
我不得不将错误处理程序的签名更改为：
options.error = function (xhr,statusTxt,thrown) {
好吧现在它有效,但我觉得我做错了.
有一个更好的方法吗？
我尝试使用jquery promises,但我需要能够从错误状态切换到成功(当调用originalSuccess时),这似乎不适用于promises.
解决方法
您可以构建自己的jQuery
Deferred object来更改默认的Backbone.sync行为
Backbone.sync = function (method,opts) {
var xhr,dfd;
dfd = $.Deferred();
// opts.success and opts.error are resolved against the deferred object
// instead of the jqXHR object
if (opts)
dfd.then(opts.success,opts.error);
xhr = Backbone.originalSync(method,_.omit(opts,'success','error'));
// success : forward to the deferred
xhr.done(dfd.resolve);
// failure : resolve or reject the deferred according to your cases
xhr.fail(function() {
if (xhr.status === 200 && xhr.responseText === "") {
dfd.resolve.apply(xhr,arguments);
} else {
if (xhr.status === 200 || xhr.status === 302 || xhr.status === 0) {
console.log('login');
}
dfd.reject.apply(xhr,arguments);
}
});
// return the promise to add callbacks if necessary
return dfd.promise();
};
承诺反映了您选择的最终状态.
http://jsfiddle.net/AsMYQ/4/为失败演示,http://jsfiddle.net/AsMYQ/5/为成功.
如果可以的话
>你可能不应该将Backbone.sync绑定到你的登录处理.使用来自Backbone或jQuery.ajaxError的事件,如@Andrey建议的那样>您的服务器响应应指示授权失败,可能是401状态>当您覆盖同步时,不要忘记返回延迟的promise / jqXHR对象,这可能会派上用场
