如何比较每个值？ [英] How to compare values in each?

问题描述

我发现比较助手的手柄 https://gist.github.com/doginthehat/1890659。
我尝试使用它：

I found compare helper for handlebars https://gist.github.com/doginthehat/1890659. And I try to use it like that:

{{#each item in model.records}}
<div>
    {{#compare model.currentUser.id item.poster_id}}
        <div class="author current">{{model.currentUser.name}}</div>
    {{else}}
        <div class="author remote">{{model.remoteUser.name}}</div>
    {{/compare}}
    <div class="td message-text">
        {{item.poster_id}}{{item.text}}
    </div>
</div>
{{/each}}

但它不工作。因为帮助器不能将第二个参数识别为整数值。助手只得到文本'item.poster_id'。我也试图用this.get（rvalue）获得帮助的值。但它仍然没有奏效。我读了很多关于它的问题，但我找不到解决方案。
请指教如何比较每个块中的值？或者也许我需要使用另一种方法。

But it doesn't work. Because helper doesn't recognize second argument as integer value. Helper gets only text 'item.poster_id'. Also I tried to get value in helper with this.get(rvalue). But it still didn't work. I read a lot of issues about it but I can't find solution. Please advise how to compare values in each block? Or maybe I need to use another approach.

推荐答案

要点中有一个问题。您需要提取缺点中的左值和右值。

There is a problem in the gist. You need to extract the lvalue and rvalue which were missing in the gist.

        lvalue = Ember.Handlebars.get(this,lvalue, options);
        rvalue = Ember.Handlebars.get(this,rvalue, options);
        var result = operators[operator](lvalue,rvalue);

这是更新的要点。
https://gist.github.com/thecodejack/a8de97f4ec410ea23722

这里是工作jsbin
http：/ /emberjs.jsbin.com/dolive/1/edit

Here is the working jsbin http://emberjs.jsbin.com/dolive/1/edit

更新：btw lvalue 和 rvalue 更正仅适用于emberjs。

Update: btw lvalue and rvalue correction is only for emberjs.

说明：基本上，由于您使用 registerHelper ，参数作为字符串值传递，而不是将其解析为变量。所以当你传递变量 var1 ， var2 （从我的jsbin链接）他们被认为是字符串var1和 var2而不是值（1，1）。

Explanation: Basically since you are using registerHelper, parameters are passed as string values rather than parsing them as variables. So when you pass variables var1 , var2(from my jsbin link) they are considered as strings "var1" and "var2" rather values(1,"1").

所以为了获取它们的值Ember提供了一个 Handlebars.get（）方法，它基本上是基于键字符串，上下文提供。文档链接 http://emberjs.com/api/classes/Ember.Handlebars.html #method_get

So inorder to fetch their values Ember provides a Handlebars.get() method which basically gets the value based on key string, context provided. Docs link http://emberjs.com/api/classes/Ember.Handlebars.html#method_get

但是如果您使用 registerBoundHelper ，则不需要 Ember.Handlebars.get（），因为params本身将具有值传递的关键字符串。文档链接 http://emberjs.com/api/classes/Ember.Handlebars.html #method_registerBoundHelper

But if you use registerBoundHelper we don't need Ember.Handlebars.get(), since params itself will have values passed rather key strings. Docs link http://emberjs.com/api/classes/Ember.Handlebars.html#method_registerBoundHelper

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