麻烦引用变量Collections.where方法中渲染功能 [英] Trouble referencing variable in Collections.where method within render function

问题描述

我遇到了一些麻烦一块骨干code的。下面的code涉及渲染功能。我可以检索所有车型。我的麻烦出现，当我尝试使用Collections.where的方法以线条为标志号＃1。正如你所看到的，我已经通过了一个对象类型，渲染功能，但由于某种原因，我无法就行＃1 customers.where方法中引用它。当我把这个方法的字面数字，如45它的工作原理。有没有解决这个某种方式让我可以通过该变量引用？

很多

感谢

 渲染：功能（选件）{    VAR认为这=;
    如果（options.id）{        VAR的客户=新客户（）;
        customers.fetch（{
            成功：函数（客户）{
   / *＃1  - ＆GT; * / VAR火枪手= customers.where（{musketeerId：options.id}）;
                的console.log（musketeers.length）//不为options.id工作是失败的最后一行
                VAR模板= _.template（$（'＃客户列表的模板）。HTML（）{
                    客户：customers.models
                }）;
                。该$ el.html（模板）;
                的console.log（customers.models）;
            }
        }）;    }其他{
        VAR模板= _.template（$（'＃客户列表的模板）HTML（）{}）;
        。该$ el.html（模板）;
    }
}
 

解决方案

尽管没有明确记载， 收藏＃其中 用途的全等（ === ）搜索时。从href=\"http://backbonejs.org/docs/backbone.html#section-101\" rel=\"nofollow\">精源$ C ​​$ C 的

 其中：函数（ATTRS，第一）{
  如果（_.isEmpty（ATTRS））先返回？无效0：[];
  返回此[第一？ 发现'：'过滤器']（函数（模型）{
    对（在ATTRS VAR键）{
      如果（！ATTRS [关键] == model.get（键））返回false;
    }
    返回true;
  }）;
}，
 

注意 ATTRS [关键] == model.get（键）的回调函数内，不会考虑 10 （可能的 ID 值）和 '10'（可能的搜索值从提取＆LT;输入＆GT; ）是一个匹配。这意味着，

  customers.where（{musketeerId：10}）;
 

可能会找到的东西，而

  customers.where（{musketeerId：'10'}）;
 

不会的。

您可以避开这样的事情与 parseInt函数 ：

  //的路要走，你从中提取`＆LT值;输入＆GT;`...
options.id = parseInt函数（$ input.val（），10）;
 

I have run into some trouble with a piece of backbone code. The code below relates to a render function. I can retrieve all the models. My trouble arises when I try to use the "Collections.where" method at line marked number #1. As you can see, I have passed an object literal into the render function but for some reason I am unable to reference it within the customers.where method on line #1. When I give this method a literal number like 45 it works. Is there some way around this so I can pass the variable reference in?

Thanks alot

render: function(options) {

    var that = this;
    if (options.id) {

        var customers = new Customers();
        customers.fetch({
            success: function (customers) {
   /* #1 --> */ var musketeers = customers.where({musketeerId: options.id});
                console.log(musketeers.length) //doesn't work as options.id is failing on last line
                var template = _.template($('#customer-list-template').html(), {
                    customers: customers.models
                });
                that.$el.html(template);
                console.log(customers.models);
            }
        });

    } else {
        var template = _.template($('#customer-list-template').html(), {});
        that.$el.html(template);
    }
}

解决方案

Although it isn't explicitly documented, Collection#where uses strict equality (===) when searching. From the fine source code:

where: function(attrs, first) {
  if (_.isEmpty(attrs)) return first ? void 0 : [];
  return this[first ? 'find' : 'filter'](function(model) {
    for (var key in attrs) {
      if (attrs[key] !== model.get(key)) return false;
    }
    return true;
  });
},

note the attrs[key] !== model.get(key) inside the callback function, that won't consider 10 (a probable id value) and '10' (a probable search value extracted from an <input>) to be a match. That means that:

customers.where({musketeerId: 10});

might find something whereas:

customers.where({musketeerId: '10'});

won't.

You can get around this sort of thing with parseInt:

// Way off where you extract values from the `<input>`...
options.id = parseInt($input.val(), 10);

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