javascript - 主干模型在错误验证时设置值

Question

我正在学习 backbone.js 并试图弄清楚如何使用验证方法。但我的问题是当我要求验证时验证被触发但它仍然保存无效数据。如此处所示 player.set('firstName', '', { validate: true }); 我将 lastName 变量设置为 '' 并保存该值，但它不应该。

编辑 - 更新了代码，现在它可以正常工作主干模型。

var Player = Backbone.Model.extend({
    defaults: {
        firstName: "Not specified",
        lastName: "Not specified",
        position: "Not specified"
    },
    validate: function (attributes) {
        // validate first name
        if (!attributes.firstName || attributes.firstName === '') {
            return 'you must have a first name';
        }
        // validate last name
        if (!attributes.lastName || attributes.lastName === '') {
            return 'you must provide a last name.';
        }
        // validate position
        if (!attributes.position || attributes.position === '') {
            return 'you must provide a position.';
        }
    },
    initialize: function () {
        // checks when firstName has changed
        this.on('change:firstName', function () {
            console.log("firstName attribute has changed.");
        });
        // checks when lastName has changed
        this.on('change:lastName', function () {
            console.log("lastName attribute has changed.");
        });
        // checks when position has changed
        this.on('change:position', function () {
            console.log("position attribute has changed.");
        });
        // check for valid inputs
        this.on('error', function (model, error) {
            console.log(error);
        });
    }
});

我在 chrome 开发工具中执行以下代码。

var player = new Player;
player.set({ firstName: "peter", lastName: "andrews", position: "outfield" }, { validate: true });
player.toJSON();
firstName attribute has changed. app.js:32
lastName attribute has changed. app.js:36
position attribute has changed. app.js:40
Object {firstName: "peter", lastName: "andrews", position: "outfield"}

player.set('firstName', '', { validate: true });
player.toJSON();
you must have a first name app.js:14
Object {firstName: "peter", lastName: "andrews", position: "outfield"}

Answer 1

来自Backbone docs :

If the attributes are valid, don't return anything from validate; if they are invalid, return an error of your choosing.

您的验证函数正在使用 console.log 打印错误字符串，但不返回任何内容。

尝试将您的 validate 函数更改为如下内容:

validate: function (attributes) {
    // validate first name
    if (!attributes.firstName || attributes.firstName === '') {
        return 'you must have a first name';
    }
    // validate last name
    if (!attributes.lastName || attributes.lastName === '') {
        return 'you must provide a last name.';
    }
    // validate position
    if (!attributes.position || attributes.position === '') {
        return 'you must provide a position.';
    }
},