主干模板方法.为什么我们传入一个模型? [英] Backbone template method. Why are we passing in a model?

问题描述

我不明白为什么我们将 model.toJSON() 传入这个模板:

app.TodoView = Backbone.View.extend({tagName: 'li',模板:_.template($('#item-template').html()),渲染:函数(){this.$el.html(this.template(this.model.toJSON()));返回这个；//启用链式调用}});

这个例子来自这个教程.

this.template(this.model.toJSON()) 对我来说是令人困惑的部分.模板方法似乎没有接受参数，对吗?这是怎么回事?

解决方案

Underscore _.template function 接受一个模板字符串作为参数(和可选的设置对象)并返回一个新的预编译模板函数，该函数接受一个对象作为参数.

这个对象是模板中使用的数据:

//创建模板函数var templateFunc = _.template("<%= name %>");//使用传递的数据渲染模板templateFunc({ name: "Émile" });//<span>埃米尔</span>

<块引用>

默认情况下，template 将数据中的值放置在本地通过 with 语句作用域.但是，您可以指定单个带有 variable 设置的变量名称.

_.template("Using 'with': <%= data.answer %>", {variable: 'data'})({answer: 'no'});

model.toJSON() 返回浅拷贝或attributes 模型的哈希值.

实现上面例子的等效:

var model = new Backbone.Model({ name: "Émile" });templateFunc(model.toJSON());//<span>埃米尔</span>

<小时>

对于 v1.7 之前的 Underscore.js，模板函数签名有点不同:

_.template(templateString, [数据], [设置])

如果传入一个数据对象，它没有返回函数，而是直接返回渲染后的模板字符串.

_.template('This is <%= val %>.', { val: "deprecated" });//这已被弃用.

I can't figure out why we are passing in a model.toJSON() into this template:

app.TodoView = Backbone.View.extend({
  tagName: 'li',
  template: _.template($('#item-template').html()),
  render: function(){
    this.$el.html(this.template(this.model.toJSON()));
    return this; // enable chained calls
  }
});

The example comes from this tutorial.

this.template(this.model.toJSON()) is the confusing part to me. The template method doesn't seem to take in an argument right? What is going on?

解决方案

Underscore _.template function takes a template string as argument (and optionally a settings object) and returns a new pre-compiled template function which takes an object as an argument.

This object is the data used within the template:

// creates a template function
var templateFunc = _.template("<span><%= name %></span>");

// render the template using the passed data
templateFunc({ name: "Émile" }); // <span>Émile</span>

By default, template places the values from your data in the local scope via the with statement. However, you can specify a single variable name with the variable setting.

_.template("Using 'with': <%= data.answer %>", {variable: 'data'})({answer: 'no'});

model.toJSON() returns a shallow copy or the attributes hash of the model.

To achieve the equivalent of the above example:

var model = new Backbone.Model({ name: "Émile" });
templateFunc(model.toJSON()); // <span>Émile</span>

---

For Underscore.js before v1.7, the template function signature was a little different:

_.template(templateString, [data], [settings]) 

If a data object was passed, it didn't returned a function, but returned the rendered template string directly.

_.template('This is <%= val %>.', { val: "deprecated" });
// This is deprecated.

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